PROPERTIES OF CIVIL ENGINEERING MATERIALS 2024 FOR STUDENTS

PROPERTIES OF CIVIL ENGINEERING MATERIALS Engr. Nana Kwame Obeng-Ahenkora (PE. IET , MGIOC, SM-CIOB) Dept of Civil & Env. Engineering CIVL 158 3 CREDIT HOURS

CIVL 158: PROCEM Objective To expose students to the behaviour of various materials used in Civil Engineering Content Properties of materials used in structural engineering design and construction (with particular reference to Ghana): concrete, timber, bricks (engineering and architectural), steel, admixtures and additives; Manufacture, composition and properties of cement; Types and properties of aggregates: laboratory and practical work includes aggregate grading; batching concrete mix proportioning and mixing; properties of wet concrete, workability measurement, casting and testing of cubes, Foundations and any other relevant materials COURSE OUTLINE

CIVL 158: PROCEM Assignments Course Works Group Work / Presentation Unannounced Quizzes Attendance ASSESSMENT

CIVL 158: PROCEM Phones should be on silent / off No eating and Chit chatting during lectures No copying of assignments Lateness will not be entertained / Be seated before start of lecture Raise your hand before speaking or leaving your seat. Use positive language Do not interrupt one another Respect your classmates and your Lecturer/Teaching Assistant Give advance notice in case you will miss the class Missing 3 lectures – You forfeit the course RULES

CIVL 158: PROCEM Civil engineering is a professional engineering discipline that deals with the design, construction, and maintenance of the physical and naturally built environment, including works like roads, bridges, canals, dams, and buildings. Civil engineering is the second-oldest engineering discipline. It is traditionally broken into several sub-disciplines including architectural engineering, environmental engineering, geotechnical engineering, structural engineering, transportation engineering, water resource engineering etc. Civil engineering takes place in the public sector from municipal through to national governments, and in the private sector from individual homeowners through to international companies. Introduction: Civil Engineering

CIVL 158: PROCEM A material engineer must be familiar with a wide range of materials used in a wide range of structures Responsibilities of a material engineer include but not limited to the following: Selection of materials for different structural components (roofs, walls, floors, sub-structures, etc.) Specification of materials Quality control of materials Introduction: Civil Engineering

CIVL 158: PROCEM There are five primary areas that must be evaluated in selecting appropriate materials and assemblies, as shown in Figure below: Material compatibility with climatic (environment) and cultural conditions Material compatibility with aesthetic conditions Construction consideration such as the applicability of material to occupancy and size of building, including durability, structural, and fire protection requirements Economic factors such as the environmental impact of obtaining raw materials, processing and fabricating building materials, transportation impact, Initial and ongoing costs, and recycling issues Mechanical and non-mechanical properties of the building materials Material Selection Criteria

CIVL 158: PROCEM Material Selection Criteria Material selection

CIVL 158: PROCEM CLASSIFICATION OF CIVIL ENGINEERING MATERIALS Material selection According to their phases According to their internal structure & chemical composition

CIVL 158: PROCEM CLASSIFICATION OF CIVIL ENGINEERING MATERIALS Material selection According to their phases Gases : Air, oxygen, CO2 Liquids : Water, chemical admixtures Semi-solids : Fresh pastes, mortars, asphalt Solids : Metals, hardened concrete

CIVL 158: PROCEM CLASSIFICATION OF CIVIL ENGINEERING MATERIALS Material selection According to their internal structure & chemical composition Metals : (formed by metallic bonds) Ferrous (iron, cast iron, steel) Non-ferrous (aluminum, copper, zinc, lead) Polymers : (long chains having molecules of C, H, O, N which are formed by covalent bonding. The chains are bound to eachother either by covalent bonds or Van der Waal’s forces.) Natural (rubber, asphalt, resins, wood) Artificial (plastics)

CIVL 158: PROCEM CLASSIFICATION OF CIVIL ENGINEERING MATERIALS Material selection According to their internal structure & chemical composition Ceramics : (mainly aluminosilicates formed by mixed bonding, covalent and ionic) Structural clay products (bricks, tiles, pipes) Porcelains Composite Materials : Natural (agglemerates) Artificial (Portland cement, concrete)

CIVL 158: PROCEM CLASSIFICATION OF CIVIL ENGINEERING MATERIALS Material selection According to their internal structure & chemical composition Reinforced Composite Materials : (reinforced concrete, reinforced plastics) One of the most important task of an engineer is to select the most suitable material for a given civil engineering structure.

CIVL 158: PROCEM Basic Properties of Building Materials Material selection Materials have different properties depending on what they are used for. Some materials are hard, others are soft. These are types of materials most commonly used in everyday life are given below. Physical Properties of Materials Chemical Properties of Materials Thermal Properties of Materials Electrical Properties of Materials Magnetic Properties of Materials Optical Properties of Materials Mechanical Properties of Materials

CIVL 158: PROCEM Basic Properties of Building Materials Material selection

CIVL 158: PROCEM PHYSICAL Properties of Materials Material selection Physical properties of the building material constitute the physical qualities needed to assess the material qualities without the aid of any external force. The following are the physical characteristics of engineering materials. Before getting into the physical properties, the relationship between weight and volume should be understood clearly A physical property is a characteristic of a substance that can be observed without changing the substance into another substance. (You can see it without changing what you’re looking at into something else.)

CIVL 158: PROCEM PHYSICAL Properties of Materials Material selection Examples physical properties include: Volume Mass Weight Size Density Melting point Boiling point

CIVL 158: PROCEM PHYSICAL Properties of Materials Material selection Examples physical properties include: density specific gravity porosity permeability surface energy

CIVL 158: PROCEM PHYSICAL Properties of Materials Material selection Other physical properties include: Color Hardness Odor Taste State of matter Texture Luster (shine) Flexibility Heat conductivity Electrical conductivity Solubility (ability to dissolve in water.) Shape Viscosity Ductility Malleability

CIVL 158: PROCEM CHEMICAL Properties of Materials Material selection A Chemical property is a characteristic of a substance that can only be observed by changing it into a different substance. Before getting into the physical properties, the relationship between weight and volume should be understood clearly The chemical composition of engineering material indicates the elements which are combined together to form that material. Chemical composition of a material effects the properties of engineering materials very much. The strength, hardness, ductility, brittleness, corrosion resistance, weldability etc. depends on chemical composition of materials. Hence, we should also have the knowledge of chemical composition of engineering materials.

CIVL 158: PROCEM CHEMICAL Properties of Materials Material selection Some of the chemical properties of engineering materials are listed below – Chemical composition Atomic bonding Corrosion resistance Acidity or Alkalinity

CIVL 158: PROCEM CHEMICAL Properties of Materials Material selection Chemical Composition The chemical composition of engineering material indicates the elements which are combined together to form that material. Chemical composition of a material effects the properties of engineering materials very much. The strength, hardness, ductility, brittleness, corrosion resistance, weldability etc. depends on chemical composition of materials. Hence, we should also have the knowledge of chemical composition of engineering materials. For Example the Chemical compositions of some materials are listed below

CIVL 158: PROCEM CHEMICAL Properties of Materials Material selection Sl. No. Material Chemical Composition 1. Steel Fe, Cr, Ni 2. Brass Cu = 90%, Ni = 10% 3. Bronze 90% Cu, 10% Ni 4. Invar Fe = 64%, Ni = 36% 5. Gun Metal Cu = 88%, Tin = 10%, Zn = 2% 6. German Silver or Nickel Silver or Electrum Cu = 50%, Zn = 30%, Ni = 20% 7. Nichrome Ni = 60%, Cr = 15%, Fe = 25% 8. Phosphor Bronge Cu = 89 – 95.50% , Tin = 3.50 -10%, P = 1% 9. Manganin Cu = 84%, Mn = 12%, Ni = 4% 10. Constantan Cu = 60%, Ni = 40%

CIVL 158: PROCEM CHEMICAL Properties of Materials Material selection Atomic bonding represents how atoms are bounded to each other to form the material. Many properties, such as melting point, boiling point, thermal conductivity and electrical conductivity of materials are governed by atomic bonding of materials. Hence, to understand the properties of materials, it is very important to study the atomic bonding of materials. Atomic bonds in materials are of following types, Ionic bond – forms by exchanging of valence electrons between atoms. Covalent bonds – forms by sharing of electrons between atoms. Metallic bonds – found in metals. Atomic bonding

CIVL 158: PROCEM CHEMICAL Properties of Materials Material selection Corrosion is a gradual chemical or electrochemical attack on a metal by its surrounding medium. Due to the corrosion, metal starts getting converted into an oxide, salt or some other compound. Corrosion of a metals is effected by many factors such as air, industrial atmosphere, acid, bases, slat solutions and soils etc. Corrosion has a very adverse effect on materials. Due to corrosion, the strength and life of a material is reduced. Corrosion resistance of a material is the ability of material to resist the oxidation in atmospheric condition. Generally pure metals such as iron, copper, aluminium etc. gets corroded in slowly in atmosphere. To avoid the corrosion of these metal in pure form, we use these metals in the form of alloys such as stainless steel, brass, bronze, German silver, Gunmetal etc. Corrosion Resistance

CIVL 158: PROCEM CHEMICAL Properties of Materials Material selection Acidity or Alkalinity is an important chemical property of engineering materials. A material is acetic or Alkane, it is decided by the ph value of the material. Ph value of a material varies from 0 to 14. Ph value of 7 is considered to be neutral. Ordinary water is having ph value of 7. The materials which are having ph value below 7 are called Acetic and Materials which are having ph value greater than 7 are called alkane. Acidity of Alkalinity of material indicates that how they react with other materials. Acidity or Alkalinity

CIVL 158: PROCEM ASSIGNMENT 1 Material selection Explain into details the other properties that are not explained in this slide

CONCRETE

CIVL 158: PROCEM WHAT IS CONCRETE Material selection Construction material Mixture of Portland cement, water, aggregates, and in some cases, admixtures. The cement and water form a paste that hardens and bonds the aggregates together. Often looked upon as “man made rock”. Versatile construction material, adaptable to a wide variety of agricultural and residential uses. Strong, durable, versatile, and economical.

CIVL 158: PROCEM WHAT IS CONCRETE Material selection Can be placed or molded into virtually any shape and reproduce any surface texture. The most widely used construction material in the world. In the United States almost twice as much concrete is used as all other construction materials combined. The ready-mix concrete producer has made concrete an appropriate construction material for many applications.

CIVL 158: PROCEM WHAT IS CONCRETE Material selection Concrete is a mixture of sand, gravel, crushed rock or other aggregate held together by a hardened paste of cement and water. This mixture, when properly proportioned, is at first a plastic mass that can be cast or molded into a predetermined size and shape. Upon hydration of the cement by the water, concrete becomes stone like in strength, hardness and durability

CIVL 158: PROCEM INGREDIENTS CONCRETE Material selection

CIVL 158: PROCEM INGREDIENTS CONCRETE Material selection Typically comprised of cement, gravel, sand and water, minor differences in the cement variants used to make concrete may occur, but sand, gravel and water remain constant. Cement the main ingredient, the most commonly used variant is Portland Cement. Gravel used to increase the internal strength of the mix by the concrete contractor, if made without it, it wouldn't be able to support heavy loads and could quickly break down and cause cracks to form on the surface.

CIVL 158: PROCEM INGREDIENTS CONCRETE Material selection Sand this is used to fill the holes left between the particles of gravel, as air pockets are not conducive to a good concrete mix. Adding sand also helps to smooth out the mix. Water used to help mix the other 3 ingredients together, it gives concrete its workability, and how much water is used, will determine the strength of the concrete mix.

CIVL 158: PROCEM ADVANTAGES OF CONCRETE Material selection Abilit y to be cast E conomical D urable F ire resistant E nerg y efficient O n - site fabrication Versatility

CIVL 158: PROCEM DISADVANTAGES OF CONCRETE Material selection Compared to other binding materials, the tensile strength of concrete is relatively low. Concrete is less ductile. The weight of concrete is high compared to its strength. Concrete may contain soluble salts. Soluble salts cause efflorescence

CIVL 158: PROCEM COMPOSITION OF CONCRETE Material selection Cement + Coarse Aggregate + Fine Aggregate + Water + Chemical Admixtures In its simplest form, concrete is a mixture of paste and aggregates. The word concrete comes from the Latin word " concretus " (meaning compact or condensed). Concrete solidifies and hardens after mixing with water and placement due to a chemical process known as hydration. The water reacts with the cement, which bonds the other components together, eventually creating a robust stone-like material. Concrete is used more than any other man-made material in the world. As of 2006, about 7.5 cubic kms of concrete are made each year—more than one cubic meter for every person on Earth

CIVL 158: PROCEM COMPOSITION OF CONCRETE (WATER) Material selection Water acts as lubricant for the fine and coarse aggregates and acts chemically with the cement to form the binding paste for the aggregate and reinforcement. Water is also used for curing the concrete after it has been cast into the forms. Water used for both mixing and curing should be free from injurious amount of deleterious materials. Portable waters are generally considered satisfactory for mixing and curing of concrete. Less water in the cement paste will yield a stronger, more durable concrete; more water will give an freer-flowing concrete with a higher slump.

CIVL 158: PROCEM COMPOSITION OF CONCRETE (WATER) Material selection Impure water used to make concrete can cause problems when setting or in causing premature failure of the structure. Hydration involves many different reactions, often occurring at the same time. As the reactions proceed, the products of the cement hydration process gradually bond together the individual sand and gravel particles and other components of the concrete, to form a solid mass.

CIVL 158: PROCEM COMPOSITION OF CONCRETE (WATER-CEMENT RATIO) Material selection Water-Cement ratio is the ratio of volume of water mixed in concrete to volume of cement used. The strength and workability of concrete depend to a great extent on the amount of water used. For a given proportion of the materials, there is an amount of water which gives the greatest strength. Amount of water less than this optimum water decreases the strength and about 10 percent less may be insufficient to ensure complete setting of cement. More, than optimum water increases the workability but decrease the strength. An increase in 10% above the optimum may decrease the strength approximately by 15% while an increase in 50% may decrease the strength to one-half.

CIVL 158: PROCEM COMPOSITION OF CONCRETE (WATER-CEMENT RATIO) Material selection The use of an excessive amount of water not only produces low strength but increases shrinking, and decreases density and durability. According to Abram’s Water-Cement Ratio law, lesser the water-cement ratio in a workable mix, greater will be its strength. According to Powers, cement does not combine chemically with more than half the quantity of water in the mix. Water-cement ratio needs to be about 0.25 to complete the hydration reaction. Typical values of w/c are between 0.35 and 0.40 because they give a good amount of workability without sacrificing a lot of strength.

CIVL 158: PROCEM COMPOSITION OF CONCRETE (AGGREGATES) Material selection Aggregates, which account for 60 to 80 percent of the total volume of concrete, are divided into two distinct categories. Coarse Aggregate Aggregate size more than 4.75mm Gravels constitute the majority of coarse aggregate used in concrete with crushed stone making up most of the remainder Fine Aggregate Aggregate size less than 4.75mm Fine aggregates generally consist of natural sand or crushed stone with most particles passing through a sieve.

CIVL 158: PROCEM COMPOSITION OF CONCRETE (AGGREGATES) Material selection Aggregate processing consists of crushing, screening, and washing the aggregate to obtain proper cleanliness and gradation. Once processed, the aggregates are handled and stored in a way that minimizes segregation and degradation and prevents contamination. Aggregates strongly influence concrete's freshly mixed and hardened properties, mixture proportions, and economy Sand, gravel and crushed stone are the primary aggregates used. All aggregates must be essentially free of silt and/or organic matter

CIVL 158: PROCEM COMPOSITION OF CONCRETE (CEMENT) Material selection Crystalline compound of calcium silicates and other calcium compounds having hydraulic properties. Considered hydraulic because of their ability to set and harden under or with excess water through the hydration of the cement’s chemical compounds or minerals

CIVL 158: PROCEM COMPOSITION OF CONCRETE (CEMENT) Material selection Uses Main use is in the fabrication of concrete and mortars Modern uses Building (floors, beams, columns, roofing, piles, bricks, mortar, panels, plaster) Transport (roads, pathways, crossings, bridges, viaducts, tunnels, parking, etc.) Water (pipes, drains, canals, dams, tanks, pools, etc.) Civil (piers, docks, retaining walls, silos, warehousing, poles, pylons, fencing) Agriculture (buildings, processing, housing, irrigation

CIVL 158: PROCEM COMPOSITION OF CONCRETE (CEMENT) Material selection Hydraulic Cements Hydraulic lime: Only used in specialized mortars. Made from calcination of clay-rich limestones. Natural cements: Misleadingly called Roman. It is made from argillaceous limestones or interbedded limestone and clay or shale, with few raw materials. Because they were found to be inferior to portland , most plants switched. Portland cement: Artificial cement. Made by the mixing clinker with gypsum in a 95:5 ratio.

CIVL 158: PROCEM COMPOSITION OF CONCRETE (CEMENT) Material selection Hydraulic Cements Portland-limestone cements: Large amounts (6% to 35%) of ground limestone have been added as a filler to a portland cement base. Blended cements: Mix of portland cement with one or more SCM (supplementary cemetitious materials) like pozzolanic additives. Pozzolan-lime cements: Original Roman cements. Only a small quantity is manufactured in the U.S. Mix of pozzolans with lime.

CIVL 158: PROCEM COMPOSITION OF CONCRETE (CEMENT) Material selection Hydraulic Cements Masonry cements: Portland cement where other materials have been added primarily to impart plasticity. Aluminous cements: Limestones and bauxite are the main raw materials. Used for refractory applications (such as cementing furnace bricks) and certain applications where rapid hardening is required. It is more expensive than Portland. There is only one producing facility in the U.S.

CIVL 158: PROCEM COMPOSITION OF CONCRETE (CEMENT - PORTLAND CEMENT) Material selection Most active component of concrete The greatest unit cost in concrete, Its selection and proper use are important in obtaining most economically the balance of properties desired for any particular concrete mixture. The production process for Portland cement first involves grinding limestone or chalk and alumina and silica from shale or clay.

CIVL 158: PROCEM COMPOSITION OF CONCRETE (CEMENT - PORTLAND CEMENT) Material selection Type I/II Portland cements are the most popular cements used by concrete producers Type I cement is the general purpose cement and most common type. Unless an alternative is specified, Type I is usually used. Type II cement releases less heat during hardening. It is more suitable for projects involving large masses of concrete--heavy retaining walls

CIVL 158: PROCEM COMPOSITION OF CONCRETE (TYPES- PORTLAND CEMENT) Material selection Cement type Use I 1 General purpose cement , when there are no extenuating conditions II 2 Aids in providing moderate resistance to sulfate attack III When high-early strength is required IV 3 When a low heat of hydration is desired (in massive structures) V 4 When high sulfate resistance is required IA 4 A type I cement containing an integral air-entraining agent IIA 4 A type II cement containing an integral air-entraining agent IIIA 4 A type III cement containing an integral air - entraining agent

CIVL 158: PROCEM COMPOSITION OF CONCRETE (PROPERTIES OF CEMENT) Material selection Fineness, Soundness Consistency Setting time Compressive strength Heat of hydration Loss of ignition

CIVL 158: PROCEM PRODUCTION OF CONCRETE Material selection

CIVL 158: PROCEM PRODUCTION OF CONCRETE (MIXING) Material selection The operation of manufacture of concrete is called ‘mixing’. The mixing can be done by two methods: HAND MIXING Mixing is done manually on a steel plate,, 2m x 2m in size or on a clean hard surface. This method is resorted to when the quantity of concrete needed for the work is small. Sand and cement in appropriate proportions are mixed first in a dry state. The coarse aggregate is then added and the whole mixture is mixed thoroughly with the help of shovels. The predetermined amount of water is then sprinkled over the mix, till the colour of concrete obtained is homogeneous and workable mix is obtained.

CIVL 158: PROCEM PRODUCTION OF CONCRETE (MIXING) Material selection MACHINE MIXING Concrete should normally be mixed in a mechanical mixer. The main part of the mixer is a drum in which the ingredients are mixed thoroughly by mechanically rotating the drum. The drum is made of steel plates, with a number of blades put in inclined position in the drum. As the drum rotates, the materials encounter resistance to rotation from the blades and this disturbing effects helps in a good mixing of the ingredients. The mixers are either operated electrically or else are driven by oil engines attached to them. Coarse aggregate should be fed first, then sand and lastly cement.

CIVL 158: PROCEM PRODUCTION OF CONCRETE (MIXING) Material selection MACHINE MIXING (CONT’D) In the revolving state, when the three get thoroughly mixed, water should be added either with the help of a can or automatically through the pipe attached to the mixer. Mixing should be continued until there is a uniform distribution of the materials and the mass is uniform in colour and consistency, but in no case shall the mixing be done for less than two minutes . Concrete mixers may be of two types: Batch Mixers Continuous Mixers

CIVL 158: PROCEM PRODUCTION OF CONCRETE (MIXING) Material selection MACHINE MIXING (CONT’D) Batch type mixers are employed for work of relatively small magnitude. Batch type mixers can either be of tilting drum type or closed drum type. In the tilting drum type, drum rotates about a trunnion axis and is so arranged that it is quiet easy to rotate and tilt it when it is empty as well as when full. In the close drum type, the drum remains rotating in one direction and is emptied by means of the hopper which tilts to receive the discharge Continuous mixers are used in mass concreting work where a large and continuous flow of concrete is required. In these mixtures, processes of feeding, mixing and emptying go on continuously without break.

CIVL 158: PROCEM PRODUCTION OF CONCRETE (TRANSPORTING) Material selection Concrete should be handled from the place of mixing to the place of final deposit as rapidly as practical by methods which will prevent the segregation or loss of any of the ingredients. If the segregation does occur during transport, the concrete should be remixed before being placed. During hot or cold weather, concrete should be transported in deep containers, on account of their lower ration of surface area to mass, reduce the rate of loss of water by evaporating during hot weather and loss of heat during cold weather.

CIVL 158: PROCEM PRODUCTION OF CONCRETE (PLACING) Material selection The concrete should be placed and compacted before setting commences and Should not subsequently be disturbed. Method of placing should be such as to preclude segregation. Before concrete is placed, it should be ensured that the forms are rigid, in their correct position, well cleaned and oiled. Oiling of these forms will prevent the concrete from sticking to it, and it will then be easier to remove the forms when they are no longer required.

CIVL 158: PROCEM PRODUCTION OF CONCRETE (PLACING) Material selection Concrete should not be poured into the forms only at one point, but should be uniformly spread on all the sides for better compaction. When the work has to be resumed on a surface which has hardened, such surface should be roughened. It should then be swept clean, thoroughly wetted and covered with a 13mm layer of mortar composed of cement and sand in the same ratio as the cement and sand in the concrete mix.

CIVL 158: PROCEM PRODUCTION OF CONCRETE (PLACING) Material selection The Surface should be thoroughly wetted and all free water removed. The surface should then be coated with neat cement grout. The first layer of concrete to be placed on this surface should not exceed 150mm in thickness, and should be well –rammed against old work, particular attention being paid to corners and close spots.

CIVL 158: PROCEM PRODUCTION OF CONCRETE (PLACING) Material selection This 13mm layer of mortar should be freshly mixed and placed immediately before the placing of the concrete. Where the concrete has not fully hardened, all laitance should be removed by scrubbing the wet surface with wire or bristle brushes, care being taken to avoid dislodgement of particles of aggregate.

CIVL 158: PROCEM PRODUCTION OF CONCRETE (COMPACTING) Material selection The removal of entrapped air during production of concrete and the uniform, dense arrangement of the constituents of concrete are effected during the compacting of corners. The density and consequently, the strength and durability of concrete depend upon this operation. Concrete should be thoroughly compacted during the operation of placing and thoroughly worked around the reinforcement, around embedded fixtures and into corners of the form work.

CIVL 158: PROCEM PRODUCTION OF CONCRETE (COMPACTING) Material selection Concrete is compacted by vibration, during which the vibrator communicates rapid vibrations of low amplitude to the particles, as a result of which the concrete becomes fluid, that is to say, its mobility is increased, and the particles, in movement, under the force of gravity occupy a more stable position, which volume of concrete is least. Vibrators are of three general types: Internal Vibrators, External Vibrators, Surface Vibrators.

CIVL 158: PROCEM PRODUCTION OF CONCRETE (COMPACTING) Material selection Internal or immersion vibrators consists of a vibrating element enclosed in a casing which is immersed in fresh concrete and transmit vibrations through the vibrator body. External or form vibrators are fastened to the form work by a clamping device and transmit vibrations to the concrete through the form. In precast members of concrete, the vibrating tables are very helpful. These tables vibrate the entire mass of concrete uniformly.

CIVL 158: PROCEM PRODUCTION OF CONCRETE (COMPACTING) Material selection Surface vibrators, set up on the concrete surface after placing, transmit vibrations to it through a working platform. They are generally employed in concrete road construction. Mechanical method of compacting the concrete is used only when the mix is stiff. Over-vibration or vibration of very wet mixes is harmful and should be avoided. Alternatively, concrete may be compacted manually by rodding, temping or hammering. Rodding is generally done to compact thin vertical members while temping is done for compacting concrete for slabs etc.,

CIVL 158: PROCEM PRODUCTION OF CONCRETE (CURING) Material selection Concrete that has been specified, batched, mixed, placed, and finished "letter-perfect" can still be a failure if improperly or inadequately cured. Usually the last step in a concrete project and, unfortunately, is often neglected even by professionals

CIVL 158: PROCEM PRODUCTION OF CONCRETE (CURING) Material selection Curing has a major influence on the properties of hardened concrete such as durability, strength, water-tightness, wear resistance, volume stability, and resistance to freezing and thawing. Proper concrete curing for agricultural and residential applications involves keeping newly placed concrete moist and avoiding temperature extremes (above 90°F or below 50°F) for at least three days. A seven-day (or longer) curing time is recommended.

CIVL 158: PROCEM PRODUCTION OF CONCRETE (CURING) Material selection The best curing method depends on: Cost, Application equipment required, Materials available, Size and shape of the concrete surface. Prevent the loss of the mixing water from concrete by sealing the surface. Can be done by: Covering the concrete with impervious paper or plastic sheets, Applying membrane-forming curing compounds.

CIVL 158: PROCEM PRODUCTION OF CONCRETE (CURING) Material selection Begin the curing as soon as the concrete has hardened sufficiently to avoid erosion or other damage to the freshly finished surface. Usually within one to two hours after placement and finishing.

CIVL 158: PROCEM PRODUCTION OF CONCRETE (BATCHING) Material selection The process of measuring concrete mix ingredients by either mass or volume and introducing them into the mixer. To produce concrete of uniform quality, the ingredients must be measured accurately for each batch. Most concrete today is batched and mixed by ready mixed concrete plants \ The two methods of concrete batching are listed below. Volume Batching Weight Batching

CIVL 158: PROCEM PROPERTIES OF CONCRETE Material selection Compressive strength Workability Durability Maximum nominal size of aggregate Grading and the type of aggregates Elasticity Cracking Shrinkage cracking Tension cracking ASSIGNMENT SUBMIT: 29 TH JUNE 2023

CIVL 158: PROCEM TEST ON CONCRETE (SLUMP TEST) Material selection

CIVL 158: PROCEM TEST ON CONCRETE (COMPRESSIVE TEST) Material selection

CIVL 158: PROCEM TEST ON CONCRETE (COMPACTION TEST) Material selection

CIVL 158: PROCEM RECYCLING ON CONCRETE Material selection increasingly common method of disposing of concrete structures recycling is increasing due to -improved environmental awareness - governmental laws -economic benefits Recycling concrete provides -environmental benefits -conserving landfill spac

CIVL 158: PROCEM ASPHALT Material selection Asphalt is also referred to as bitumen whose main source is petroleum from where it is derived as the semi-solid compound and it is a thick, sticky, black, highly viscous liquid. It is classed as pitch and it is found in both natural deposits as well as in refined products. Asphaltum was the term that was used for asphalt before the 20th century. The primary use of the asphalt goes into the construction of the road which accounts for 70% of the asphalt that is explored. Here the asphalt is used as glue and the binder is mixed with the construction aggregate materials in order to develop the asphalt concrete. Sealing flat roofs, production of roofing felts and bituminous waterproofing products are the main products that are developed from asphalt other than concrete.

CIVL 158: PROCEM ASPHALT Material selection Also known as bitumen Dark brown to black Highly viscous Hydrocarbon produced from petroleum distillation residue. At least 80% carbon, which explains its deep black color. Sulphur is another ingredient. Primarily used as a sealant for rooftops and a durable surface for roads, airport runways, playgrounds and parking lots. Asphalt can be separated from the other components in crude oil By the process of fractional distillation, usually under vacuum conditions.

CIVL 158: PROCEM ASPHALT Material selection Types of Asphalt When heated, asphalt materials soften and become elastic under some conditions. Except when used as a binder or adhesive, asphalt's mechanical properties are of little importance. The grades of asphalt are as follows: Natural Asphalt Residual Asphalt Mastic Asphalt Asphalt Cement Cutback Asphalt Asphalt Emulsion

CIVL 158: PROCEM ASPHALT ( Types of Asphalt Cont’d) Material selection Natural Asphalt: Lake asphalt and Rock asphalt are two types of natural asphalt. At depths of 3 to 60 metres, lake asphalt can be found as fossil deposits in areas like Trinidad's lakes. It is made up of 40 to 70 percent pure bitumen with around 30 percent water content. Residual Asphalt : It's made by combining crude petroleum oil with an aspheric base and distilling it. Mastic Asphalt : This is also known as artificial asphalt, is made by combining the required minerals, such as limestone, dust, fine and coarse aggregates, with black bitumen that has been heated to a liquid state. It hardens into a hard elastic block as it cools. It is reheated on the job site and used for waterproofing and pavement construction. Mastic asphalt is long-lasting, rugged, water-resistant, non-absorbent, non-flammable, and quiet.

CIVL 158: PROCEM ASPHALT ( Types of Asphalt Cont’d) Material selection Asphalt Cement: It is a mixture of bitumen and asphalt with flux oils that have adhesive properties and can be used to make mastic asphalt. In the production of bituminous pavements, it is favoured. Cutback Asphalt : It is a liquid asphalt that is made up of asphalt cement and a petroleum solvent. Since they minimise asphalt viscosity for lower temperatures, they are used in bituminous paints, roof repairs, and other applications. Asphalt Emulsion : This is a suspension of small asphalt cement globules in 50 - 60% water with a 1% emulsifying agent. Tack coats, fog seals, slurry seals, bituminous surface treatments, and material stabilisation are all examples of low-temperature applications..

CIVL 158: PROCEM ASPHALT ( Types of Asphalt Cont’d) Material selection Rolled Asphalt: Made of aggregate, or solid materials such as sand, gravel, or recycled concrete, with an asphalt binder. Used to make roads and other surfaces, such as parking lots, by being applied in layers and compacted. Different types of rolled asphalt are distinguished according to the process used to bind the aggregate with the asphalt .

CIVL 158: PROCEM UNANNOUNCED QUIZ THURSDAY 22 ND JUNE 2023 Material selection DURATION: 10 MINS Explain in simple terms what concrete is and list the ingredients of concrete Explain soundness of cement What is the main responsibility of the material’s Engineer? List the processes involved in concrete production Mention 5 general properties of civil engineering materials

CIVL 158: PROCEM Material selection Hot mix asphalt concrete (HMAC) Produced at 160 degrees Celsius. This high temperature serves to decrease viscosity and moisture during the manufacturing process, resulting in a very durable material. HMAC is most commonly used for high-traffic areas, such as busy highways and airports.

CIVL 158: PROCEM Material selection Warm mix asphalt concrete (WAM or WMA) Reduces the temperature required for manufacture by adding asphalt emulsions, waxes, or zeolites. Benefits both the environment and the workers, as it results in less fossil fuel consumption and reduced emission of fumes.

CIVL 158: PROCEM Material selection Cold mix asphalt concrete , Emulsified in soapy water before mixing it with the aggregate, eliminating the need for high temperatures altogether. The asphalt produced is not nearly as durable as HMAC or WAM Typically used for low traffic areas or to patch damaged HMAC.

CIVL 158: PROCEM Material selection Mastic concrete , Also called sheet asphalt. Lower bitumen content than the rolled asphalt. Used for some roads and footpaths. Used also in roofing and flooring Stone mastic asphalt (SMA), is another variety. Becoming increasingly popular as an alternative to rolled asphalt. Benefits include -Anti-skid property -The absence of air pockets But if laid improperly May cause slippery road conditions.

CIVL 158: PROCEM PHYSICAL PROPERTIES OF ASPHALT Material selection Durability - A measure of how asphalt binder physical properties change with age. - Sometimes called age hardening . - In general, as an asphalt binder ages, its viscosity increases and it becomes more stiff and brittle. Safety Asphalt cement like most other materials, volatilizes (gives off vapor) when heated. Flash point. For safety reasons, the flash point of asphalt cement is tested and controlled.

CIVL 158: PROCEM PHYSICAL PROPERTIES OF ASPHALT Material selection Rheology The study of deformation and flow of matter. Deformation and flow of the asphalt binder in HMA is important in HMA performance. HMA pavements that deform and flow too much may be susceptible to rutting and bleeding, while those that are too stiff may be susceptible to fatigue cracking. Purity . Asphalt cement, as used in HMA paving, should consist of almost pure bitumen. Impurities are not active cementing constituents and may be harmful to asphalt performance.

CIVL 158: PROCEM AGGREGATES Material selection Aggregates are inert materials mixed with a binding material like cement or lime in the preparation of mortar or concrete. Granular material of mineral composition such as sand, gravel, shale, slag or crushed stone.

CIVL 158: PROCEM CLASSIFIACTION AGGREGATES Material selection Natural Aggregates Artificial Aggregates

CIVL 158: PROCEM NATURAL AGGREGATES Material selection All natural aggregates particles originally formed a part of a larger parent mass. many properties of the aggregates depend entirely on the properties of the parent rock. E.g. chemical and mineral composition, petrological character, specific gravity etc. some properties are possessed by the aggregates but absent in the parent rock: particle shape and size, surface texture, and absorption.

CIVL 158: PROCEM ARTIFICIAL AGGREGATES Material selection They are obtained either as a by-product or by a special manufacturing process such as heating. (blast furnace slag, expanded perlite).

CIVL 158: PROCEM CLASSIFICATION OF AGGREGATES ACCORDING TO THEIR PETROLOGICAL CHARACTERISTICS Material selection Igneous rocks: are formed by solidification of molten lava. (granite) Sedimentary rocks: are obtained by deposition of weathered & transported pre-existing rocks or solutions. (limestone) Metamorphic rocks: are formed under high heat & pressure alteration of either igneous & sedimentary rocks (marble).

CIVL 158: PROCEM CLASSIFICATION OF AGGREGATES ACCORDING TO THEIR SIZE Material selection Fine Aggregates Coarse Aggregates

CIVL 158: PROCEM FINE AGGREGATES Material selection Particles of fine aggregates pass through 4.75mm(No.4) sieve .Most commonly used fine aggregates are sand etc.

CIVL 158: PROCEM Coarse Aggregates Material selection Coarse aggregates are retained on 4.75mm sieve. Aggregates the size of whose particle is bigger than 4.75 mm but smaller than 37.5 mm are known as coarse aggregates. It specially includes gravel and crushed stones.

CIVL 158: PROCEM CLASSIFICATION OF AGGREGATES ACCORDING TO UNIT WEIGHT Material selection Heavy weight agg .: Hematite, Magnetite Specific Gravity, Gs > 2.8 Normal weight agg .:Gravel, sand, crushed stone 2.8 < Gs < 2.4 Light weight agg .:Expanded perlite, burned clay Gs < 2.4

CIVL 158: PROCEM Material selection Weight Examples of Aggregates Used Uses for the Concrete ultra-lightweight vermiculite, ceramic, diatomite, pumice, scoria, perlite, can be sawed or nailed, also used for its insulating properties (250 to 1450 kg/m3). lightweight expanded clay, shale or slate, crushed brick used primarily for making lightweight concrete for structures, also used for its insulating properties (1350 to 1850 kg/m3). normal weight crushed limestone, sand, river gravel, crushed recycled concrete used for normal concrete projects heavyweight barlite, magnetite , steel or iron shot; steel or iron pellets used for making high density concrete for shielding against nuclear radiation

CIVL 158: PROCEM Material selection Vermiculite ULTRA-LIGHTWEIGHT Aggregates Perlite Pumice Scoria Diatomite

CIVL 158: PROCEM Material selection LIGHTWEIGHT Aggregates Expanded clay (left) Expanded shale (right) Crushed Brick

CIVL 158: PROCEM Material selection NORMAL WEIGHT Aggregates River gravel Crushed Concrete Crushed Limestone

CIVL 158: PROCEM Material selection HEAVYWEIGHT Aggregates Magnetite (left) Magnetite-sand(right)

CIVL 158: PROCEM Material selection Ranges of particle sizes found in aggregates for use in concrete

CIVL 158: PROCEM Material selection PARTICLE SHAPE & SURFACE TEXTURE: In addition to petrological character, the external characteristics, i.e. The shape & surface texture of aggregates are of importance. Particle Shape Rounded : Completely water worn & fully shaped by attrition. (River Gravel) Irregular : Partly shaped by attrition so it contains some rounded edges. (Land Gravel)

CIVL 158: PROCEM Material selection PARTICLE SHAPE & SURFACE TEXTURE: Angular: Has sharp corners, show little evidence of wear. (Crushed Stone) Flaky: Thickness is relatively small with respect to two other dimensions. (Laminated Rocks) Elongated: Have lengths considerably larger than two other dimensions.

CIVL 158: PROCEM Material selection PARTICLE SHAPE & SURFACE TEXTURE: FLAT ELONGATED ANGULAR ROUND

CIVL 158: PROCEM Material selection PARTICLE SHAPE & SURFACE TEXTURE: Rounded aggregates are suitable to use in concrete because flaky & elongated particles reduce workability, increase water demand & reduce strength. In the case of angular particles, the bond between agg. Particles is higher due to interlocking but due to higher surface area, angular particles increase water demand & therefore reduce workability. As a result, for the same cement content & same workability rounded agg. Give higher strength.

CIVL 158: PROCEM Material selection SURFACE TEXTURE This affects the bond to the cement paste & also influences the water demand of the mix. 1. Smooth: Bond b/w cement paste & agg is weak. 2. Rough : Bond b/w cement paste & agg. is strong. Surface texture is not a very important property from compressive strength point of view but agg. Having rough surface texture perform better under flexural & tensile stresses.

CIVL 158: PROCEM Material selection SURFACE TEXTURE

CIVL 158: PROCEM Material selection GRADING OF AGGREGATES Grading is the particle-size distribution of an aggregate as determined by a sieve analysis using wire mesh sieves with square openings. Lecture Continues at Practical sessions

CIVL 158: PROCEM Material selection CHEMICAL ADMIXTURES Admixtures are those ingredients in concrete other than Portland cement, water, and aggregates that are added to the mixture immediately before or during mixing The major reasons for using admixtures are To reduce the cost of concrete construction To achieve certain properties in concrete more effectively than by other means To maintain the quality of concrete during the stages of mixing, transporting, placing, and curing in adverse weather conditions To overcome certain emergencies during concreting operations

CIVL 158: PROCEM Material selection CHEMICAL ADMIXTURES

CIVL 158: PROCEM Material selection CHEMICAL ADMIXTURES The most common types of admixtures are: Accelerators : - Speed up the hydration (hardening) of the concrete. - Typical materials used are CaCl 2 and NaCl. Acrylic retarders : - Slow the hydration of concrete, and are used in large or difficult pours. - Typical retarder is table sugar, or sucrose (C 12 H 22 O 11 ). Air Entraining agents : -T he most commonly used admixtures for agricultural concrete. -P roduce microscopic air bubbles throughout the concrete. - Entrained air bubbles: I mprove the durability of concrete exposed to moisture and freeze/thaw action. Improve resistance to scaling from deicers and corrosive agents such as manure or silage.

CIVL 158: PROCEM Material selection CHEMICAL ADMIXTURES Water-reducing admixtures -Increase the workability of plastic or "fresh" concrete, allowing it be placed more easily, with less consolidating effort. -High-range water-reducing admixtures are a class of water-reducing admixtures Increase workability Reduce the water content of a concrete. Improves its strength and durability characteristics.

CIVL 158: PROCEM Material selection FOUNDATIONS

CIVL 158: PROCEM Material selection FOUNDATIONS The main objectives of foundation design are to:- Ensure that the structural loads are transmitted to the subsoil safely, economically and without any unacceptable movement during the construction period and throughout the anticipated life of the building or structure

CIVL 158: PROCEM Material selection FOUNDATIONS Assessment of site conditions in the context of the site & soil investigation report Calculation of anticipated structural loading Choosing the foundation type , should consider: Soil condition Type of structure Structural loading Economic factors Time factors relative to the proposed contract period Construction problem Sizing the chosen foundation in the context of loading, ground bearing capacity & any likely future movement of the building / structure Basic Design Procedure

CIVL 158: PROCEM Material selection TYPES OF FOUNDATIONS Foundations may be broadly classified as shallow Foundation Deep foundation Shallow Foundation: According to Terzaghi, a foundation is shallow if its depth is equal to or less than its width. • Types of shallow foundation ( Assignment –submit : Thursday 17 th August 2023 ) Spread footing Combined footing Strap Footing Mat Foundation or Raft Foundation

CIVL 158: PROCEM Material selection TYPES OF FOUNDATIONS Deep Foundation those in which the depth of the foundation is very large in comparison to its width. Which are not constructed by ordinary methods of open pit excavations. Types of Deep foundation ( Assignment –submit : Thursday 17 th August 2023 ) Types of Deep Foundations: Pile foundation Pier foundation Well or cassion foundation

CIVL 158: PROCEM Material selection Bearing capacity Bearing capacity is the power of foundation soil to hold the forces from the superstructure without undergoing shear failure or excessive settlement. When a foundation is loaded it settles. This settlement increase more or less linearly with the increase in loading pressure Beyond a certain loading pressure, the foundation settles rapidly or sinks into the ground causing rupture of the ground. This loading pressure at which the failure by rupture of the ground takes place is termed as ‘Bearing capacity’ of the foundation.

CIVL 158: PROCEM Material selection TIMBER Carpentry General Advantages of Timber Use of Timber Qualities of Good Timber. Defects in Timber. Methods of seasoning

CIVL 158: PROCEM Material selection TIMBER Read more at : https://www.technologystudent.com/joints/forest3a.html

CIVL 158: PROCEM Material selection TIMBER Timber has been in very common use for- engineering purposes since ancient times. Even today there are certain works, where timber is considered as the most ideal material. Today although materials like steel, cement, stone bricks etc. have occupied lot of field, where timber was almost used, still timber continues to be an important structural material. There is difference between terms timber and wood. Wood includes all types of wood which may be burning wood, structural wood, furniture wood etc. But wood suitable for use as a structural material is called timber. So we can say: Wood is usually used to refer to the material in its natural state...timber refers to it after it has been modified by man. So you go to the forest to collect wood for the fire, and to the DIY store to get timber for doing up your house

CIVL 158: PROCEM Material selection TIMBER Timber is obtained from trees. Timber denotes structural wood. A standing living tree is known as standing timber. Rough timber. When tree has been cut and its stem and branches are roughly converted into pieces of suitable lengths. Converted timber When roughly converted timber is further sawn and converted into commercial size the planks, logs, battens, posts, beams, etc

CIVL 158: PROCEM Material selection TIMBER

CIVL 158: PROCEM Material selection ADVANTAGES OF TIMBER It is easily available every where. Its salvage value is high. It can be easily transported by converting large pieces into smaller pieces. Working on timber is easy. Timber constructions can be easily repaired. Additions and alterations to timber structures can be easily done. It can be easily jointed. In marine works, timber is considered as an ideal material as it does not corrode. Cement and iron structures corrode in sea water, if they are not protected with special preservative. Being light in weight, it is preferred for building works in earth quake prone regions. It is an excellent material for decorative and general use furniture. Lot of other internal decorations can be carried out with it. It can with stand, shocks better than iron and concrete. It is good insulator of electricity and heat. It is good sound absorbing material. Timber can be easily strengthened by attaching steel or other material with it

CIVL 158: PROCEM Material selection USES OF TIMBER

CIVL 158: PROCEM Material selection QUALITIES OF GOOD TIMBER Following are the qualities of good timber. A good timber should be hard and durable. It should be capable of resisting the actions of fungi, chemicals and physical agencies. The fibers of the timber should be straight and compact. The timber should be free from knots , wists , upsets, burls shakes, flaws etc. Its color should be dark. It should be obtained preferably from heart wood. Color should be uniform. It should be properly seasoned. Its freshly cut surface should smell sweet. Its weight should be heavy.

CIVL 158: PROCEM Material selection QUALITIES OF GOOD TIMBER Following are the qualities of good timber. It should be easily workable. It should not clog the teeth of saw and should be capable of being easily planned. Timber should be tough i.e., it should be capable of resisting shocks. It should be able to withstand the weathering affects. It should be strong enough to withstand bending, direct and shear effects efficiently. A clear ringing sound should be emitted by the timber when struck. Heavy dull sound indicates decayed timber. It should offer adequate fire resistance

CIVL 158: PROCEM Material selection

CIVL 158: PROCEM Material selection DEFECTS Defects that develop after felling the tree. Bow Cup Twist Radial shakes Wane Diagonal grains The defects that usually occur in the timber may be classified into two categories as follows: Defects that develop during growth of the tree. Shakes Twisted timber Upsets or rupture Knots Wind cracks Burls

1.Defects that develop during growth of tree have been briefly discussed as follows: 1.1 Shakes. This is most serious type of defect in timber. These are sort of cracks which partly or completely separate the fibers of wood. A shake is nothing, but separation of the timber along the grains. Shakes may be of several types. 1.1.1 Star shakes These are radial cracks or splits that extend from bark towards the sap wood. They usually remain confined up to the plane of sap wood only. The cracks are widest at the circumference and go on narrowing as they proceed towards the Centre of the tree CIVL 158: PROCEM DEFECTS

Reasons of star shake Star shakes usually develop due to fierce heat and frost When logs having this defect are sawn they usually separate out into a number of pieces and hence become useless . Star shakes CIVL 158: PROCEM DEFECTS

1.1.2 Heart shakes. These splits or cracks occur in the central part of the trees. There are widest at the centre and go on narrowing as they proceed towards outside. This defect usually occurs in over-matured trees. This defect is usually caused due to shrinkage of the heart wood. Heart shakes divide the tree cross-section into several parts. Straight running heart shake is not as serious as twisted heart shake. CIVL 158: PROCEM DEFECTS

1.1.3Cup shakes. This defect develops curved slit between successive annual rings. The split does not run for the full circumference of the annual rings. This defect usually develops due to unequal growth. Another possible reason for their development may be contraction of timber under atmospheric changes together with the twisting action of strong winds. CIVL 158: PROCEM DEFECTS

CIVL 158: PROCEM DEFECTS 1.1.4 Ring Shake When cup shake defect runs for full circumference of the annual ring, it is called ring shake. It is more serious than cup shake 1.1.5 Radial shakes. They are similar to star shakes. They are numerous, fine and irregular. They usually occur when felled tree is exposed to sun for seasoning. The cracks run for a short distance from bark to-wards the centre and then follows the course of an annual ring and ultimately goes towards the pith.

CIVL 158: PROCEM 1.1.6 Twisted Fibres They are caused by twisting of young trees constantly in one direction under the action of strong prevalent winds. Timber with twisted fibres is unsuitable for sawing. The timber having this defect is mostly used for posts and poles in an unsawn condition 1.1.7 Upset This defect is caused due to injury suffered by wood fibers by crushing or compression. Upsets are mainly due to improper felling of tree and exposure of tree in its young age to fast blowing wind. This defect indicates change in direction of wooden fibers. DEFECTS

CIVL 158: PROCEM 1.1.8 Knot Knots are generally developed at the bases of branches cut off from the tree. This phenomenon ultimately results in the formation of dark, hard rings, known as knots. As knots break the continuity of the wooden fibers , they form a source of weakness. The amount of weakness caused by the knot depends upon the position, size, and degree of grain distortion around it. Knot is the most commonly encountered defect of wood. It is impossible to procure timber free of knots. Knots may be dead, live loose, or tight. Tight knots are not objectionable unless they are too large. Their presence on tension members is objectionable. It is very difficult to plane the timber at knots. DEFECTS

CIVL 158: PROCEM 1.1.9 Wind Cracks The outer layers of a standing tree suffer from the effect of shrinkage due to atmospheric agencies. This causes cracks on the outer surface only. These cracks are known as wind cracks. DEFECTS

CIVL 158: PROCEM DEFECTS 2 . Defects that develop after felling the tree. Conversion of timber is done almost immediately after felling The tree. The defects that may develop after felling the tree and also during conversion and seasoning are the following: 2.1 Bow when planks of converted of timber shrink and bend in curved form , in the direction of length.

CIVL 158: PROCEM 2.2 Cup: this defect is indicated when wooden planks bend in curved from in transverse direction. 2.3 Twist A plank which has distorted spirally along its length DEFECTS

CIVL 158: PROCEM SEASONING OF TIMBER As fresh timber which is obtained from trees contains about 30 to 40 % sap or moisture. This sap is very harmful for the life of a timber. Therefore, it is necessary to remove that sap by applying some special methods. All those methods which are used for removing the sap from timber are collectively termed as seasoning of timber. Advantages of seasoned timber: It has reduced weight, It is strong and durable, It has resistance to decay or rot, It takes high polish, It is easier to work, Its life is more. Types of Timber Seasoning : The main types of timber seasoning are as under. Natural or Air Seasoning Water Seasoning Artificial Seasoning Kiln Seasoning, Boiling, Chemical Seasoning, Electric Seasoning, &

CIVL 158: PROCEM SEASONING OF TIMBER Natural Seasoning : In the air seasoning or natural seasoning or natural drying, seasoning of timber, timber is dried by direct action of air, wind and sun. In this method, the timber logs are arranged one over the other, keeping some space or distance between them for air circulation of fresh air. Generally this type of seasoning requires few months to over a year, this is very slow process. Kiln Seasoning : In kiln seasoning timber is placed in a chamber with some special heating arrangement. In this process one thing should be kept in mind that heating system should be under control, other wise timber will be crack or wrap . The time required for this seasoning is 3 to 12 days. This is quick process. Artificial Seasoning

CIVL 158: PROCEM SEASONING OF TIMBER Artificial Seasoning (d) Electric Seasoning: In this method electric current is passed through the timber logs. The time required for this seasoning is 05 to 08 hours. (3) Water Seasoning: In water seasoning, timber logs are kept immersed whole in the flowing water. The sap present in timber is washed away. After that logs are taken out from water and are kept in open air, so water present in timber would be dried by air. The time required for this type of seasoning is 2 to 4 weeks.

CIVL 158: PROCEM Plywood Produced by gluing many layers of split wood together. The grains are arranged alternatively to eliminate distortion. The plywood is a very good modern construction material whose quality depends on type of wood used, glue used and pressure of steam used in gluing.

c) Blocks: Very thick eg. 25 x 25 mm(width-depth) or 20 x 25 mm or 30 x 30 mm BLOCK Many grades of wood exist depending on the strength. BLOCK CIVL 158: PROCEM

BRICK TECHNOLOGY CIVL 158: PROCEM

CIVL 158: PROCEM

History of Brick Masonry A No one really knows the age of brick masonry. B Common sense would dictate that the lack of construction materials for shelter in lands where no natural stone was available, would lead to innovations with whatever material is at hand C Where there was land there was soil, and if there was water there was mud. And soil particles stick together and form a hard mass when the sun dries the moisture. D Mud bricks were molded by hand and allowed to dry in the sun, and stockpiled for future use. Small units were easily handled. CIVL 158: PROCEM

E Mud bricks were stacked with mud mortar, which varied in thickness to accommodate irregular shapes. F It was learned that the best bricks were made of soil that had very tiny particles and became sticky when wet. The material we call clay. G In the southwest regions of North America, “Adobe” bricks were made of a clay that has come to be known as adobe clay, which was particularly good for making mud bricks. Adobe was further strengthened by adding short strands of straw to the mix. Adobe bricks are still made and used today. CIVL 158: PROCEM

H Consistency of size did not become prevalent until units were cast into molds, which greatly facilitated ease of assembly. I The industrial revolution of the late 1800s brought about the firing of masonry in kilns, which made the units very hard and strong. J In the early 1900s other materials surpassed brick in use because of strength requirements for buildings too tall and heavy to be supported by a “mass” type wall. K But brick has and intimacy about it that remains a warm and friendly material for use in construction of residences and office buildings CIVL 158: PROCEM

BRICK MORTAR A Mortar is a vital part of brick construction. B As bricks are made of clay, then fired in a furnace to remove the moisture and make them hard, they are impossible to make in exact, consistent size – but in modern day it is close . C In early times, mortar was used as a cushion to align the assembly process to maintain square and plumb in a structure. Additional strength in the mortar mix was not necessary because it was made of the same material as brick. D But since fired bricks are much stronger than the original sun-dried clay, the strength of mortar was improved to make stronger buildings. CIVL 158: PROCEM

E With the development of natural cement for the manufacture of concrete , it became a natural matrix for masonry mortar. F Mortar is a mix much like concrete; which consists of stone aggregates held together by a matrix. In the case of concrete, that consists of a gradation of large rocks, smaller rocks, and still smaller particles (sand) – all mixed consistently and held together by a paste of cement and water, which hardens by a chemical process called hydration. G Masonry mortar is a mixture of sand, cement, and water, with the addition of lime to lend smoothness and workability to the mix. CIVL 158: PROCEM

Mortar Functions Provides for full bearing of weight Maintains the strength of the masonry wall Seals against moisture and vermin Bonds the masonry units together It should be a part of the aesthetic value of a building. CIVL 158: PROCEM

MAKING BRICKS A Early molding of bricks was done by shaping a mass of mud by hand. B Then individual single molds made of wood increased production and consistency of size. C Then multiple molds made of wood increased production even more. D Today, very sophisticated methods exist for shaping bricks by extruding clay through a steel form, then cutting to individual units with wire. CIVL 158: PROCEM

Wood molds for making brick CIVL 158: PROCEM

E The making of bricks became more sophisticated with units extruded and wire cut, then fired in gas kilns. Production and quality of units increased tremendously. F The color of bricks up until approximately 20 years ago depended upon the color of clay, which was found in large deposits in the ground. G Constant use of brick as a veneer in residential and commercial construction as population grew, led to depletion of consistent color clay deposits. H Now, nearly all brick used in residential construction are made of any clay, but given their color by a slurry mix that is applied to the units before firing. CIVL 158: PROCEM

Basic types of brick: Common brick : Units made of clay where color and surface finish are not a factor, because of use as a “backup” structural material in an area where it will never be seen. Face brick : Units made where appearance is the main consideration. Face brick for commercial use is still made with specific colors of clay. Special bricks may be made for specific purposes. Should an Architect desire a special shape to be used in creating an unusual desired effect in a design, brick companies will custom make the units. CIVL 158: PROCEM

Fire brick is made of a specific type of white clay, with special additives for use in the firebox of fireplaces, ovens, kilns, and other firing mechanisms. Bricks, generally are made with holes (except fire brick) to reduce the weight of material not needed for structure, and to provide a method for additional adherence of mortar. Bricks made of the same material as concrete masonry units are available on a limited basis, but have never been accepted for widespread use. CIVL 158: PROCEM

BRICK SHAPES AND SIZES The text shows a chart with 12 sizes of bricks, but all available sizes and shapes are not listed. Two shapes of brick are commonly used, but many others are made for specific purpose. Modular Brick – nominally lay 8” long, 4” thick, & 3 courses high = 8”. Texas Tech uses modular brick. For use where strength and appearance is important. King Size Brick – nominally lay 10” long, 3” thick, & 2 ½” high. For use as a veneer where economy is the main concern. CIVL 158: PROCEM

Eight modular size bricks are required to lay one square foot of surface wall, but it takes only 5.4 king size bricks for the same area. So, king size brick are made strictly for economy. Bricks shapes made for appearance: Roman brick – basically 12” long, 4” thick, 1 ½” high. Norman brick – basically 12” long, 4” thick, 3 courses = 8” high. Big Johns – basically 12” long, 4” thick, 4” high. CIVL 158: PROCEM

BRICK ARRANGEMENT TERMINOLOGY A Bricks are laid in a variety of arrangements , mostly today for the sake of appearance. In earlier times when a wall consisted of several layers thickness, bricks were turned endways through the wall for structural bond. Named patterns evolved in the process, such as English bond, Flemish bond, etc. B Common course pattern for structure and appearance: Stretcher – Bricks laid flat end to end. Soldier – Laid vertically so the outside long edge shows. Rowlock - Laid so the end shows, vertically. Header – Laid so the end shows, horizontally CIVL 158: PROCEM

Basic Brickwork Terminology Bed Joint Head Joint Course - horizontal layer of brick CIVL 158: PROCEM

Brickwork Terminology Header - Bonds two wythes together Wythe: vertical layer 1 unit thick Soldier - Laid on its end, face parallel Rowlock - laid on face, end visible Stretcher - long dimension horizontal & face parallel to the wall CIVL 158: PROCEM

Brick Masonry - Sizes and Shapes There is No standard size Normal coursing - 3 modular bricks = 8” Larger sizes available Custom shapes & colors are available CIVL 158: PROCEM

CIVL 158: PROCEM

Masonry Joints Various tools are used to treat the surface finish of mortar joints. Some are done to repel water, but most are done for appearance . CIVL 158: PROCEM Concave Flush Raked Stripped Struck Weathered Vee

Concave joints done primarily for weather proofing CIVL 158: PROCEM

Raked joints are made primarily for appearance CIVL 158: PROCEM

PORTLAND CEMENT CIVL 158: PROCEM

Portland Cement → Gypsum+Portland Cement Clinker (pulverizing) Portland Cement Clinker → Calcareous & Clayey Materials (burning) Paste → P.C. + Water Mortar → P.C. + Water + Sand Concrete → P.C. + Water + Sand + Gravel CIVL 158: PROCEM

RAW MATERIALS OF P.C. Calcareous Rocks (CaCO 3 > 75%) Limestone Marl Chalk Marine shell deposits Argillocalcareous Rocks (40% < CaCO 3 < 75%) Cement rock Clayey limestone Clayey marl Clayey chalk CIVL 158: PROCEM

Argillaceous Rocks (CaCO 3 < 40%) Clays Shales Slates Portland cement is made by mixing substances containing CaCO 3 with substances containing SiO 2 , Al 2 O 3 , Fe 2 O 3 and heating them to a clinker which is subsequently ground to powder and mixed with 2-6 % gypsum. CIVL 158: PROCEM

CLINKER GYPSUM CIVL 158: PROCEM

PRODUCTION STEPS Raw materials are crushed, screemed & stockpiled. Raw materials are mixed with definite proportions to obtain “raw mix”. They are mixed either dry (dry mixing) or by water (wet mixing). Prepared raw mix is fed into the rotary kiln. As the materials pass through the kiln their temperature is rised upto 1300-1600 ° C. The process of heating is named as “burning”. The output is known as “clinker” which is 0.15-5 cm in diameter. Clinker is cooled & stored. Clinker is ground with gypsum (3-6%) to adjust setting time. Packing & marketting. CIVL 158: PROCEM

CIVL 158: PROCEM

REACTIONS IN THE KILN ~ 100 ° C→ free water evaporates. ~ 150-350C °→ loosely bound water is lost from clay. ~ 350-650 ° C → decomposition of clay→SiO 2 &Al 2 O 3 ~ 600 ° C → decomposition of MgCO 3 → MgO&CO 2 (evaporates) ~ 900 ° C → decomposition of CaCO 3 → CaO&CO 2 (evaporates) ~ 1250-1280 ° C → liquid formation & start of compound formation. ~ 1280 ° C → clinkering begins. ~ 1400-1500 ° C → clinkering ~ 100 ° C → clinker leaves the kiln & falls into a cooler. Sometimes the burning process of raw materials is performed in two stages: preheating upto 900 ° C & rotary kiln CIVL 158: PROCEM

CHEMICAL COMPOSITION OF P.C. Portland cement is composed of four major oxides (CaO, SiO 2 , Al 2 O 3 , Fe 2 O 3 ≥90%) & some minor oxides. Minor refers to the quantity not importance. Oxide Common Name Abbreviation Approx. Amount (%) CaO Lime C 60-67 SiO 2 Silica S 17-25 Al 2 O 3 Alumina A 3-8 Fe 2 O 3 Iron-oxide F 0.5-6 MgO Magnesia M 0.1-4 Na 2 O Soda N 0.2-1.3 K 2 O Potassa K SO 3 Sulfuric Anhydride Ś 1-3 CaO→limestone SiO 2 -Al 2 O 3 →Clay Fe 2 O 3 →Impurity in Clays SO 3 →from gypsum→not from the clinker CIVL 158: PROCEM

The amount of oxides in a P.C. Depend on the proportioning of the raw materials and how well the burning is done in the kiln. The chemical composition is found by chemical analysis. A typical analysis of O.P.C. Insoluble residue=0.2 Loss on ignition=1.4 C 63.6 S 20.7 A 6 F 2.4 Ś 2.1 M 2.6 N 0.1 K 0.9 Free C 1.4 Total 99.8 CIVL 158: PROCEM

CaO (C), SiO 2 (S), Al 2 O 3 (A) & Fe 2 O 3 are the major oxides that interact in the kiln & form the major compounds. The proportions of these oxides determine the proportions of the compounds which affect the performance of the cement. SO 3 →comes largely from gypsum P.C. alone sets quickly so some gypsum is ground with clinker to retard the setting time. CIVL 158: PROCEM

If too much gypsum is included it leads to distruptive expansions of the hardened paste or concrete. ASTM C 150 → SO 3 ≤ 3% in O.P.C. MgO+H 2 O→MH C+H→CH volume expansion & cause cracking. ASTM C 150 → M < 6% free C < 3% CIVL 158: PROCEM

Alkalies (Na 2 O & K 2 O) may cause some dificulties if the cement is used with certain types of reactive aggregates in making concrete. The alkalies in the form of alkaline hydroxides can react with the reactive silica of the aggregate & resulting in volume expansion after hardening. This process may take years. Na 2 O & K 2 O ≤ 0.6% CIVL 158: PROCEM

Insoluble Residue: is that fraction of cement which is insoluble in HCl. It comes mainly from the silica which has not reacted to form compounds during the burning process in the kiln. All compounds of P.C. is soluble in HCl except the silica. The amount of I.R., determined by chemical analysis, serves to indicate the completeness of the reactions in the kiln. ASTM C 150 → I.R. ≤ 0.75% CIVL 158: PROCEM

Loss on Ignition (L.O.I.): is the loss in weight of cement after being heated to 1000 ° C. It indicates the prehydration or carbonation due to prolonged or improper storage of cement & clinker. If cement is exposed to air, water & CO 2 are absorbed & by heating the cement upto 1000 ° C loose these two substances. ASTM C 150 → L.O.I. ≤ 3% for O.P.C. CIVL 158: PROCEM

COMPOUND COMPOSITION OF P.C. (OR CLINKER) Oxides interact with eachother in the kiln to form more complex products (compounds). Basically, the major compounds of P.C. can be listed as: Name Chemical Formula Abbreviations Tri Calcium Silicate 3CaO.SiO 2 C 3 S Di Calcium Silicate 2CaO.SiO 2 C 2 S Tri Calcium Aluminate 3CaO.Al 2 O 3 C 3 A Tetra Calcium Alumino Ferrite 4CaO.Al 2 O 3 .Fe 2 O 3 C 4 AF CIVL 158: PROCEM

The degree to which the potential reactions can proceed to “equilibrium” depends on: Fineness of raw materials & their intermixing. The temperature & time that mix is held in the critical zone of the kiln. The grade of cooling of clinker may also be effective on the internal structure of major compounds. CIVL 158: PROCEM

There are also some minor compounds which constitute few %, so they are usually negligible. Moreover, portland cement compounds are rarely pure. For example in C 3 S, MgO & Al 2 O 3 replaces CaO randomly. C 3 S→ALITE & C 2 S→BELITE Ferrite Phase: C 4 AF is not a true compound. The ferrite phase ranges from C 2 AF to C 6 AF. *C 4 AF represents an average. CIVL 158: PROCEM

RETAINING WALLS CIVL 158: PROCEM

RETAINING WALL Basic function – to retain soil at a slope which is greater than it would naturally assume, usually at a vertical or near vertical position CIVL 158: PROCEM

CIVL 158: PROCEM

Retaining wall failure at the Shin-Kang Dam CIVL 158: PROCEM

Design of retaining wall retaining walls have primary function of retaining soils at an angle in excess of the soil’s nature angle of repose. Walls within the design height range are designed to provide the necessary resistance by either their own mass or by the principles of leverage. Design consideration: Overturning of the wall does not occur Forward sliding does not occur Materials used are suitable The subsoil is not overloaded CIVL 158: PROCEM

Factors which designer need to take account Nature and characteristics of the subsoil's Height of water table – the presence of water can create hydrostatic pressure, affect bearing capacity of the subsoil together with its shear strength, reduce the frictional resistance between the underside of the foundation Type of wall Materials to be used in the construction CIVL 158: PROCEM

CIVL 158: PROCEM

Failure of retaining wall (dam) due to water pressure.. CIVL 158: PROCEM

Types of walls Mass retaining walls Cantilever walls Counterfort retaining walls Precast concrete retaining walls Precast concrete crib-retaining walls CIVL 158: PROCEM

Mass retaining walls Sometimes called gravity walls and rely upon their own mass together with the friction on the underside of the base to overcome the tendency to slide or overturn Generally only economic up to 1.8 m Mass walls can be constructed of semi-engineering quality bricks bedded in a 1:3 cement mortar or of mass concrete Natural stone is suitable for small walls up to 1m high but generally it is used as a facing material for walls over 1 m CIVL 158: PROCEM

Typical example of mass retaining walls BRICK MASS RETAINING WALL CIVL 158: PROCEM

Brick retaining wall Stone retaining wall CIVL 158: PROCEM

Typical example of mass retaining walls MASS CONCRETE RETAINING WALL WITH STONE FACINGS CIVL 158: PROCEM

Cantilever walls Usually of reinforced concrete and work on the principle of leverage where the stem is designed as a cantilever fixed at the base and the base is designed as a cantilever fixed at the stem Economic height range of 1.2 m to 6 m using pre-stressing techniques Any durable facing material can be applied to the surface to improve appearance of the wall CIVL 158: PROCEM

Cantilever wall CIVL 158: PROCEM

Two basic forms:- A base with a large heel A cantilever with a large toe Cantilever L Cantilever T CIVL 158: PROCEM

CIVL 158: PROCEM

Cantilever walls CIVL 158: PROCEM

CIVL 158: PROCEM

Counterfort retaining walls Can be constructed of reinforced or prestressed concrete Suitable for over 4.5 m Triangular beams placed at suitable centres behind the stem and above the base to enable the stem and base to act as slab spanning horizontally over or under the counterforts CIVL 158: PROCEM

CIVL 158: PROCEM

Precast concrete retaining wall Manufactured from high-grade pre cast concrete on the cantilever principle. Can be erected on a foundation as permanent retaining wall or be free standing to act as dividing wall between heaped materials which it can increase three times the storage volume for any given area Other advantages- reduction in time by eliminating curing period, cost of formwork, time to erect and dismantle the temporary forms Lifting holes are provided which can be utilized for fixing if required CIVL 158: PROCEM

application CIVL 158: PROCEM

CIVL 158: PROCEM

Precast concrete retaining walls CIVL 158: PROCEM

Pre cast concrete crib-retaining walls Designed on the principle of mass retaining walls A system of pre cast concrete or treated timber components comprising headers and stretchers which interlock to form a 3 dimensional framework or crib of pre cast concrete timber units within which soil is retained Constructed with a face batter between 1:6 and 1:8 Subsoil drainage is not required since the open face provides adequate drainage. CIVL 158: PROCEM

CIVL 158: PROCEM

Retaining Wall Uses Retaining walls are stabilizing structures that are used for holding back earth. There are many reasons for building these structures. Improve Property’s Appearance Create a Flat Area Make a Slope Useful Provide Handicapped Accessibility Improve Site Drainage Hold Back Water Simplify Maintenance CIVL 158: PROCEM

Retaining Wall Uses Improve Property’s Appearance With proper materials selection, retaining walls can become a highly attractive aesthetic feature of your property. They are wonderful devices for creating interest features in a landscape. You have probably seen many upscale entryways that utilize retaining walls to create a raised area for signage or to frame the entrance with raised landscaping beds. CIVL 158: PROCEM

Retaining Wall Uses Create a Flat Area Flat ground is almost always more useful than a steep slope. A retaining wall can convert a slope into a flat level area. This can allow for the construction of structures that otherwise couldn't be built on such a property, like a parking lot, sports field, or building. CIVL 158: PROCEM

Retaining Wall Uses Make a Slope Useful In many places around the world, whole mountainsides are cut into a series of steps supported by a series of retaining walls. Called terracing, this technique turns land that is too steep to grow crops into useful farm land. You can utilize this technique on your commercial property, too. Terracing can prevent erosion on steep areas, and can make a steep landscape far easier — and less costly — to maintain. CIVL 158: PROCEM

Retaining Wall Uses Provide Handicapped Accessibility Retaining walls are often used to create gently sloped ramps for wheelchair access CIVL 158: PROCEM

Retaining Wall Uses Improve Site Drainage Sometimes a retaining wall can be very useful in directing water on a property. They are also often used to address slope issues near bodies of water. If you are considering building one for this purpose, be aware that there are many local and state regulations that must be followed. It’s a good idea to find out what the permitting requirements are before even starting to work on the design for such a project. CIVL 158: PROCEM

Retaining Wall Uses Improve Site Drainage A seawall is a specialized type of retaining wall that separates land from water. Others function to protect the shore from erosion, to keep the shoreline from shifting, or to create a harbor or docking area for boats. Don’t forget, though — permitting requirements apply here as well! CIVL 158: PROCEM

Retaining Wall Uses Simplify Maintenance It is a lot easier to maintain a flat area than to have to prune, mow, or plant a slope. They also provide a natural separation between turf and beds. Over time, these easy-care features can shave significant amounts from the cost of landscape maintenance. CIVL 158: PROCEM

Waterproofing Structures Below Ground subject to penetration of ground water More extreme, if below H 2 O table Two basic approaches to Waterproofing Waterproof Membranes, or Drainage Generally - both used in tandem CIVL 158: PROCEM

Waterproofing Membranes Materials Liquid or Sheet (Plastic, asphaltic, synthetic rubber) Coatings (asphaltic) Cementitious Plasters & admixtures Bentonite clay Accessories Protection Board Waterstop Unit of Measure - SF, Mils (thickness) CIVL 158: PROCEM

Stone & Perforated Pipe Drainage Mat & Perforated Pipe Drainage Methods CIVL 158: PROCEM

CIVL 158: PROCEM

Damp proofing Typically, a liquid asphalt applied with a roller or sprayer Not an effective barrier for water under pressure. BUT, will prevent ground ‘moisture’ from migrating through a wall. Typically used in conjunction will drainage pipe. CIVL 158: PROCEM

Other Topics Paints Prefabrication Construction Robotics Reinforcements CIVL 158: PROCEM

PROPERTIES OF CIVIL ENGINEERING MATERIALS 2024 FOR STUDENTS

About This Presentation

Slide Content

Tags

Categories

Download

Quick Actions

Statistics

Related Slideshows

PROPERTIES OF CIVIL ENGINEERING MATERIALS 2024 FOR STUDENTS

About This Presentation

Slide Content

Slide 1

Slide 2

Slide 3

Slide 4

Slide 5

Slide 6

Slide 7

Slide 8

Slide 9

Slide 10

Slide 11

Slide 12

Slide 13

Slide 14

Slide 15

Slide 16

Slide 17

Slide 18

Slide 19

Slide 20

Slide 21

Slide 22

Slide 23

Slide 24

Slide 25

Slide 26

Slide 27

Slide 28

Slide 29

Slide 30

Slide 31

Slide 32

Slide 33

Slide 34

Slide 35

Slide 36

Slide 37

Slide 38

Slide 39

Slide 40

Slide 41

Slide 42

Slide 43

Slide 44

Slide 45

Slide 46

Slide 47

Slide 48

Slide 49

Slide 50

Slide 51

Slide 52

Slide 53

Slide 54

Slide 55

Slide 56

Slide 57

Slide 58

Slide 59

Slide 60

Slide 61

Slide 62

Slide 63

Slide 64

Slide 65

Slide 66

Slide 67

Slide 68

Slide 69

Slide 70

Slide 71

Slide 72

Slide 73

Slide 74

Slide 75

Slide 76

Slide 77