Unit I _1 Stones.pptx

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1. Building Construction Practice & Concrete Technology

2. List out the materials used in a Building

3. CIVIL ENGINEERING MATERIALS

4. S T ONES The stones which are suitable for the construction of the structures such as retaining walls, abutments, dams, barrages, roads etc . Building stones should possess enough strength and durability . Ex: Granite, sandstone, lime stone, marble, slate etc

5. S T ONES

6. S T ONES

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9. COMMON USES OF BUILDING STONE: U sed in foundations of buildings, Used in construction of dams, barrages, etc, C rushed ( powdered ) form , is used as artificial sand, U sed as raw material for manufacturing of cement, U sed as material for construction of road and railway tracks , if it is in broken form U sed as decorative material in buildings, U sed as parts of buildings such as lintels and arches, etc, It is also used as thin slabs for building roofing, U sed for ornamental works in buildings

10. Uses of stone as a building material are: Used in stone masonry , where it is naturally available. As coarse aggregate in cement concrete (crushed form of rock). As a roofing material in the form of slates. As a flag or thin slab for paving. As a soling material in the construction of highways and runways. As ballast for railway tracks. As a veneer for decorative front and interior of buildings. Limestone for construction of important buildings like temples, churches and mosques. Limestone for the manufacture of cement and as a flux in blast furnace.

11. Uses of stone as a building material are: Used in stone masonry , where it is naturally available. As coarse aggregate in cement concrete (crushed form of rock). As a roofing material in the form of slates. As a flag or thin slab for paving. As a soling material in the construction of highways and runways. As ballast for railway tracks. As a veneer for decorative front and interior of buildings. Limestone for construction of important buildings like temples, churches and mosques. Limestone for the manufacture of cement and as a flux in blast furnace.

12. Characteristics of good building stones: Hardness Durability Appearance Strength Toughness Weathering Workability Fire resistance Specific gravity

13. Characteristics of good building stones: Hardness: Hardness indicates resistance to cutting and resistance to abrasion (rub with each other). S tones are generally used in roads and railway tracks construction . Ex: Loss Angles Abrasion test . Durability: Durability is the power of stone resist ance from atmospheric and other external effects. It depends upon: Chemical composition, Physical structure, Resistance to weathering effects, Place where it is used

14. (3) Porosity and Absorption: Stone can hold water either through porosity or absorption. L ess porous stones absorb less moisture. Porous stones are not suitable for building construction . Decomposition : Gases and acids in rain water dissolve some constituents of stone and cause the stone decay. Disintegration : In cold countries water freezes and expands and thus disintegrates the stones. (6) Reliability : When exposed to fire stone , it should resist fire. Characteristics of good building stones:

15. Appearance and color : Bright color stones are preferred for architectural purpose but those are soft and less durable . Physical Strength : Crystalline structures are more durable than non-crystalline structure stone Seasoning Qualities : A good building stone should have good seasoning qualities. The period 3-6 months are enough for seasoning. Fire resistance : A good building stone should be fire resistant. Basalt and trap resist fire but some varieties of igneous and metamorphic stones are very weak against fire . Characteristics of good building stones:

16. Rocks Sedimentary (S) Rocks Ex: sand stone, lime, mud stones Metamorphic (M) Rocks formed due to Pr. & temp If Pr. is high, Ex: marble/quartzite If temp is high shale/schist Igneous (I) Rocks formed due to temp Ex: basalt/granite in extreme temps magma Formation is f(Pr. and temp)

17. Geological Cycle: Weathering of Rocks – Transportation - Deposition - Upheaval

18. Classification of rocks (stones) or varieties of stones: There are three main classes of rocks. (1) Chemical classification : Chemically stones are stones are classified into three groups. (i) Argillaceous Rocks: Argillaceous or clay stones are those stones which contain (alumina Al 2 O 3 ) (clay) as principal constituent. These stones are less durable stones. All clay stones belong to this group. Ex: Slate , Laterite, etc.

19. Silicious Rocks: The stones which contain (Silica SiO 2 ) as principal constituent are called silicious rocks. These stones are durable stones . Ex: granite, q uartzite and s and stone etc . Calcareous Rocks: The stones which contain calcareous material (CaCO3) as principal constituent are called calcareous rocks. They also contain some proportion of siliceous and clay matter . Ex: marble stone and lime stone, etc.

20. (2) PHYSICAL CLASSIFICATION: Physically rocks are classified as: Stratified Rocks: The rocks which are split into thin slabs or layers easily are called stratified rocks. Ex: Slate , Sand stone and Lime stone . Unstratified Rocks: These rocks cannot be easily split into thin slabs or layers are called unstratified rocks. All igneous rocks are essentially unstratified and metamorphic rocks may be either stratified or unstartified. Ex: Granite , Basalt Foliated rocks: These rocks have a tendency to be split up in a definite direction only . Foliated structure is very common in case of metamorphic rocks.

21. (3) GEOLOGICAL CLASSIFICATION: S tones are classified into three groups as per this calssification . (i) Igneous or Primary Rocks : These are primary rocks which are formed from molten magma. They represent different structural features depending upon the condition of solidification and composition. Generally igneous rocks are strong and durable. These are also called unsratified or eruptive rocks. Ex: granite, basalt, trap, etc.

22. (ii) Sedimentary or Secondary Rocks : These rocks are formed by transportation of particles from one location to other place . These are also called aqueous and stratified rocks . (or) The rocks which are formed by gradual deposition are called Sedimentary Rocks. Ex: Lime stone, sand stone, etc.

23. (iii) Metamorphic or Tertiary Rocks : Rocks which are formed due to metamorphic action of pressure or internal heat or by both (or) alteration of original structure due to heat and excessive pressure are called Metamorphic Rocks. Ex: Marble etc .

24. Tests on Building Stones Following are different tests on building stones: Acid test Attrition test Crushing test Freezing and thawing test Hardness Test Impact test Durability Test Microscopic Test Smith’s Test https://www.youtube.com/watch?v=7R-kSKws444 https://civiljungle.com/tests-on-stones/

25. Acid Test on Building Stone This test is carried out to understand the presence of calcium carbonate in building stone. This test gives the weathering resistance of the stone. A good building stone maintains its sharp edges and keeps its surface free from powder at the end of this test. If the edges are broken and powder is formed on the surface, it indicates the presence of calcium carbonate and such a stone will have poor weathering quality. This test is usually carried out on sand stones .

26. Attrition Test on Building Stone This test is done to find out the rate of wear of stones, which are used in road construction. The results of the test indicates the resisting power of stones against the grinding action under traffic. Quantity of material which is retained on the sieve is weighed. Percentage wear worked out as follows: Percentage wear = (Loss in Weight/Initial Weight) x 100 

27. Crushing Test on Building Stone Stone is cut into cubes of size 40 x 40 x 40 mm are finely dressed and finished. Specimen should be placed in water for about 72 hours before testing. Load is applied axially on the cube in a crushing test machine. Rate of loading is 140 kg/sq.cm per minute.

28. Freezing and thawing test Stone specimen is kept immersed in water for 24 hours. It is then placed in a freezing machine at -12 degC for 24 hours. Then it is thawed or warmed at atmospheric temperature. This should be done in shade to prevent any effect due to wind, sun rays, rain etc. This procedure is repeated several times and the behaviour of stone is carefully observed.

29. Hardness Test on Building Stone This test is carried out to determine the hardness of a stone. A cylinder of diameter 25mm and height 25mm is taken out from the sample of stone. Dorry’s testing machine is used for testing. The coefficient of hardness is found out from the following equation: Coefficient of hardness = 20 – (Loss of weight in gm/3) Alternatively, scratch the surface of stone with a knife

30. Impact Test To determine toughness of stone, impact test is carried out. The resistance of stones to impact is found by conducting tests in impacting the testing machine. It consists of a frame with guides where a  metal hammer weighing 13.5 to 15 kg  can freely fall from a  height of 380 mm.

31. Impact Test Aggregates of size 10 mm to 12.5 mm  are filled in a  cylinder in 3 equal layers,  every layer being  tamped 25 times. The same is then transferred into the  cup and again tamped 25 times . The hammer is then allowed to  fall freely onto the specimen 15 times . The specimen is then  sieved through a 2.36 mm sieve . Then, Impact value =  W2 / W1 where, W2 = Weight of Fines. W1 = Original Weight. The recommended impact values for various works are: (a) for wearing course ≯ 30% (b) for bituminous macadam ≯ 35% (c) for water-bound macadam ≯ 40%

32. Microscopic Test Geologists take thin sections of stones and placed under the microscope to study the various properties such as Average grain size Existence of pores, fissures, veins and shakes Mineral constituents Nature of cementing material Presence of any harmful substance Texture of stones etc.

33. Smith’s Test This test is performed to find the presence of soluble matter in a sample of stone. Few chips or pieces of stone are taken and they are placed in a glass tube. The tube is then filled with clear water. After about an hour, the tube is vigorously stirred or shaken. Presence of earthy matter will convert the clear water into dirty water. If water remains clear, stone will be durable and free from any soluble matter. This test is a qualitative test

34. Durability Test Durability or soundness test is performed to fine out the capacity of the stone to resist disintegration and decomposition. Durability = change in the mass in%

35. Tests on Building Stones Water Absorption Test The test is carried out as follows: From the sample of stone, a cube weighing about 50gm is prepared. Its actual weight is recorded as W1 gm. Cube is then immersed in distilled water for a period of 24 hrs. Cube is taken out of water and surface water is wiped off with a damp cloth. It is weighed again. Let the weight be W2 gm. Cube is suspended freely in water and its weight is recorded. Let this be W3 gm. Water is boiled and cube is kept in boiling water for 5 hours. Cube is removed and surface water is wiped off with a damp cloth. Its weight is recorded. Let it be W4 gm. From the above observations, values of the following properties of stones are obtained. Percentage absorption by weight after 24 hours =(W2 – W1) x 100 / W1 Percentage absorption by volume after 24 hours = (W2 – W1) x 100 / (W2 – W3) Volume of displaced water = W2 – W3 Percentage porosity by volume = (W4 – W1) x 100 / (W2 – W3) Density =W1 / (W2 – W3) kg/m3 Specific Gravity = W1 / (W2 – W3) Saturation Coefficient = (Water Absorption/Total Porosity) = (W2 – W1) / (W4 – W1)