Mortar and Concrete overall surkhi function

Function of surkhi and mortar

1. 7.4. FUNCTIONS OF SAND AND SURKHI IN MORTARS 7.4.1. Functions of sand. It is used as an adulterant just to make the mortar economical. It does not provide any strength and hydraulicity to the mortar. It reduces the shrinkage of the binding material. It prevents development of cracks in the mortar on drying. It helps in hardening of fat lime by making it porous. It allows carbon dioxide, present in the air, to reach insider the mortar mass easily and thus helps in earlier setting of the mortar. It helps in making mortars and concretes of any desired strength by varying its proportion with the binding material.

2. 7.4. FUNCTIONS OF SAND AND SURKHI IN MORTARS A well graded sand adds density to the mortars and the concretes. It helps in forming a hardened mass of silicates as it is now believed that some chemical reaction takes place between silica and constituents of the cementing materials, particularly of lime and surkhí. 7.4.2. Functions of surkhi. It acts as an adulterant to make the mortar economical. It provides strength and hydraulicity to the mortar. It provides brick colour to the lime mortar.

3. STRENGTH OF MASONARY LAID DIFFERENT MORTARS Brick masonry in 1 : 3 cement mortar 1000KN/ sq. m Brick masonry in 1 : 4 cement mortar 880KN/ sq. m Brick masonry in 1 : 6 cement mortar 500KN/ sq. m Brick masonry in lime mortar. 440KN/ sq. m Ashlar stone masonry in 1: 3 cement mortar 1700KN/ sq. m Rubber masonry in 1 : 3 cement mortar 900 to 1100KN/ sq. m Rubber masonry in lime mortar. 300 to 500KN/ sq. m 7.6

4. Brick Masonry with cement Mortar Brick Masonry with Lime Mortar Ashlar Stone masonry with cement mortar Rubber masonry with cement mortar Rubber masonry with lime mortar

5. 7.7 SELECTION OF MORTAR FOR DIFFERENT ENGINEERING WORKS Very heavily stressed members of structure. 1:1 cement Sand mortar R.C.C. tanks, and other water retaining structures 1:1.5 cement sand mortar General R.C.C. works such as slabs, beams and columns; arch work or ashlar work in stone masonry, cement concrete roads, cement concrete flooring, pointing, plastering inside of swimming pools etc. 1:2 cement sand mortar Massive works, dams and retaining walls, lining of reservoirs and water channels, reinforced brickwork, half brick thick walls, columns or pillars, cornices, drip courses damp-proofing flooring, pointing, plastering etc. where fine finish is desired. 1:3 cement sand mortar

6. 7.7 SELECTION OF MORTAR FOR DIFFERENT ENGINEERING WORKS Masonry work below ground level, especially in water logged areas. 1:3 cement sand mortar or 1:3 lime sand mortar (The lime should be eminently hydraulic) Mass concrete in foundations, seining of wells, paving tiles, iron fixtures, cavity walls, plastering of ceiling and external plastering 1: 2 to 3 hydraulic lime mortar work, etc. where good finish is desired. 1: 4 cement sand mortar Ordinary brick masonry 1: 5 to 8 cement sand mortar Stone masonry in foundations and super- structures of ordinary buildings. 1 : 2 fat lime surkhii mortar

7. Loading... Introduction to Good Concrete Good concrete is essential for a wide range of construction projects. It provides the foundation for durable and sustainable structures. Presented to: Ar. Abdul Moeez . Presented by: M.Junaid , Mian Awais & Muhannad Usama

8. Characteristics of Good concrete: Crushing Strength The crushing strength of concrete, determined by breaking a cube, and often called the cube strength, reaches values of about  3 tons per square inch , that of granite 10 tons per square inch, and that of cast iron from 25 to 60 tons per square inch. Durability Durability of concrete is defined as the resistance of concrete against abrasion and deterioration. It means that how much damage a concrete member of structure can safely endure in its service life. CTM Machine Degradation of concerete due to non- durability

9. Resistance to fire Concrete provides the best fire resistance of any building material . It does not burn, it cannot be 'set on fire' like other materials in a building and it does not emit any toxic fumes, smoke or drip molten particles when exposed to fire. workability Concrete workability basically refers to  how easily freshly mixed concrete can be placed, consolidated and finished with minimal loss of homogeneity . Generally the workability of concrete is determined by how fluid the mix is (i.e. the cement to water ratio). Compactness of concrete Compaction is  the process which expels entrapped air from freshly placed concrete and packs the aggregate particles together so as to increase the density of concrete . It increases significantly the ultimate strength of concrete and enhances the bond with reinforcement. Fire resistance Compactness test

10. Impermeability of concrete The impermeability of concrete refers to  the property of concrete that cannot be pervaded by water, oil and other liquids with pressures . It plays an important role in the durability of concrete. Abrasion resistance of concrete Abrasion resistance of concrete means how well it can handle rubbing or friction without getting damaged.i.e , heavy things on them. Creep: Concrete creep is defined as:  deformation of structure under sustained load . Basically as long term pressure or stress on concrete can make it change shape. This deformation usually occurs in the direction the force is being applied. Like a concrete column getting more compressed, or a beam bending. Appearance of concrete: The appearance of concrete  can be varied by altering the proportions of the materials used or by using special additives . The material can also be coloured during the mixing process or after it is in place. Abrasion testing machine. Creep in Bridge beam

11. TOPIC 7.8 CONCRETE An artificial stone resulting from hardening of a mixture of a binding material, fine aggregate, course aggregate, and water in suitable proportion is called concrete. Preparation of different types of concrete Material required in the preparation of different types of concrete : Cement and lime are generally used as binding material. Sand, surkhi, clinder used as fine aggregate. Crushed stones, broken bricks, slag pumice, breeze, clinkers, are used as course aggregate.

12. A good Portland cement or lime , clean sand , and strong course aggregates are necessary for making a good concrete. The required strength of concrete can be obtained by : Careful selection of ingredients Correct grading of ingredients Accurate water measurement Good workmanship in mixing Transportation Placing Compaction and finishing Curing of concrete in the construction site. Concretes are usually named according to the binding material used in their preparation. Various forms of concrete is being used in the construction field these days. When building strength and durability is prime important then cement concrete is used.

13. “ Plain, reinforced and pre-stressed cement concretes are replaced other building materials very fast because , Better appearance, high crushing strength, More durability, Greater resistance to fire, Imperviousness, Quickness, Easy of monolithic construction, Long life, Less maintenance cost ,