Reinforcing material types of steel reinforcement charectristic strength of steel

Content of this Article : Reinforcing material, Suitability of Steel as Reinforcing Material, charectristic strength of steel and types of steel reinforcement REINFORCING MATERIAL Concrete is weak in tension and it is to be reinforced properly with suitable material. The purpose of providing reinforcement in R.C.C. is : To take up all the tensile stresses developed in the structure. To increase the strength of concrete sections. To prevent the propagation of cracks developed due to temperature and shrinkage stresses. To make the sections thinner as compare to plain concrete section. To fulfill above criteria the reinforcing material should satisfy the following requirements : The reinforcing material should develop a perfect bond with concrete to transfer stresses from one material to other. It should have high tensile strength. It should be cheap, easily available and durable. The coefficient of thermal expansion of the reinforcing material should be nearly same as that…

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Concrete Mix Proportioning

 Concrete Mix Proportioning Concrete Mix Proportioning Concrete Mix Proportioning : The determine of the proportions of cement, aggregates and water to attain the desired strength and properties such as workability, durability etc., is called as concrete mix proportioning. The design of concrete mix is classified into following two types by IS 456:2000 (Clause 9) : (1)       Nominal mix concrete (2)       Design mix concrete.   Nominal Mix Concrete A concrete mix in which the proportions of cement, aggregate and water are adopted is called as nominal mix. It is not necessary that such a mix will give the desired strength and properties. For example, nominal mix proportions of M15 is 1:2:4. Nominal mix is not used for grades higher than M20. It is used for ordinary concrete works only. As per IS 456:2000 (Clause 9.3.1). The proportional of materials for nominal mix concrete shall be in accordance with the following Table…

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Properties of concrete

Conetnt of This Article  Properties of concrete : compressive strength,work-ability,Workability depends upon the following factors, The work ability can be measured by the following tests, Workability Requirements for Different Works,Durability Different Exposures with Normal Weight 20 mm Aggregates,Tensile Strength, Modulus of Elasticity, Poisson's Ratio, Creep, creep coefficient, Shrinkage, Freezing and Thawing, percentage of en trained air for nominal maximum size of aggregate, Sulfate, Attack Various Types of Environment Exposure Conditions See also: Requirements of good concrete mix and Grades of concrete Properties of concrete in plastic and hardened state Water cement ratio and slump test CEMENT CONCRETE AND ITS INGREDIENTS Properties of Concrete The properties of concrete depend upon the properties and proportions of its ingredients. The following are the important properties of concrete which are used in the design :   Compressive Strength The compressive strength of concrete is determined by the cube test. The characteristic compressive strength of…

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Concrete making materials Cement Aggregate and Water

Content of this article: Concrete making materials Cement: Ordinary portland cement, Rapid hardening Portland cement, Low heat Portland  cement,  Portland slag cement, Sulfate resisting cement, Portland pozzolana cement, white cement, Aggregate and Water Concrete Making Materials (1)       Cement Cement is the only chemically active ingredient of concrete which shows binding properties after reacting with water. It consist of silicates and aluminates of calcium which form a hardened mass after mixing with water. This type of cement is also known as hydraulic cement. There are many types of cements available in market, some of which are explained below : (i)        Ordinary Portland Cement Ordinary portland cement (OPC) is commonly used in construction. The Bureau of Indian Standard has classified OPC in three grades. This classification is based on the compressive strength of cement-sand mortar cubes. The face area of these cubes shall be 50 cm2. The cube is made of 1…

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Requirements of good concrete mix and Grades of concrete

Content of this Article: Concrete, Requirements of good concrete mix, Grades of concrete, The characteristic compressive strength of concrete R.C.C. consists of concrete and reinforcing material. The strength of an R.C.C. section depends upon the kind of concrete and reinforcement used.   Concrete The properties of concrete depends upon the proportions and type of its ingredients. A properly designed concrete mix is very durable. Requirements of good concrete mix (i)        The concrete should be mixed thoroughly to from a homogeneous mix. (ii)       Concrete should be compacted properly to prevent it from being porous. (iii)     Sufficient curing of concrete is required for developing full strength. (iv)      The water cement ratio should be appropriate, considering the strength and workability criteria. (v)       The concrete mix should be designed properly and should have all the ingredients in right proportions. (vi)      The water used for mixing should be free from all harmful organic substances.…

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Retaining walls and Breast walls

Content of The Article : Retaining walls and Breast walls, Retaining walls,Retaining wall Terminology,Back fill,Back fill slope,Batter,Dowels,Footing, Footing key,Weep wholes, Grade, Heel, Horizontal temperature/shrinkage reinforcing, Keyway, Principal reinforcing, Retained height, Stem, Surcharge, Toe, Breast Walls. Retaining walls and Breast walls Retaining walls. The walls constructed for retaining or supporting earth against their back are called retaining walls. Earth cannot remain vertical but would be in a state of equilibrium when it assumes a natural angle which is called angle of repose. If it is desired to be retain the earth vertically, that portion of the earth will have to be supported by a wall called retaining wall. The back of the wall is in the form of steps and the face of the retaining wall may be either vertical or battered. The width at the base will depend upon the height of earth to be retained as the more the height,…

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Various types of bonds used in brick masonry

Content of this article : Types of bonds, Stretcher bond, Header bond, English bond, main features of English bond,Arrangement of Bricks in English Bond, Flemish bond, Dutch bond, Garden wall bond, Raking bond,Two varieties of raking bond viz., Diagonal bond and Herring bone bond, Facing bond. See also : Technical terms in masonry Comparison of Brick and Stone Masonry Brick masonry Earth composition of Bricks Types of Bonds The bricks being uniform in size can be arranged in a variety of ways. The following are the various types of bonds used in brick masonry : Stretcher Bond. In this type of Bond all the bricks are laid as stretchers, that is length wise, as shown in Fig. 2.29. This bond is used-in half brick thick walls. Header Bond In this bond, all the bricks are laid all headers. The elevation of the wall laid in header bond is shown in Fig.…

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Brick Masonry

Brick Masonry The art of construction in bricks is called brick masonry; Bricks are laid with cement mortar or lime mortar. In ordinary and inferior quality of works, mud mortar is also used. Brick masonry laid with cement mortar is stronger and more durable than that laid, with lime mortar. But lime mortar is very commonly used due to its low cost. Bricks are made in a range of varieties, each intended for a specific purpose, but all are created from some combination of sand, water, clay, and heat. Building brick, or common brick, is used in construction and is often "cored" with two rows of holes to save material and reduce weight. Face brick is chosen for visible surfaces or exposed walls and comes in different colors, sizes, and shapes. Firebrick is made with special clay to offer additional heat resistance in fireplaces or boiler rooms. Glazed brick is…

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Technical Terms in masonry

Technical Terms in masonry Back and Backing. The internal surface of the wall is called back and the material used on the back is called backing. Face and Facing. The outer or exposed face of the wall is called face and the material used on the face is called facing. Hearting and Filling. The interior portion of wall between the face and back is called hearting and filling. Prepeds. These are imaginary lines containing vertical joints of the masonry. Voids. These are spaces left between the blocks of stone in the masonry. Spalls. These are chips or stone pieces used for backing up or filling the interstices in stone masonry. String course. It is a horizontal projecting course of masonry, usually projecting from the face of the wall, intended to throw off rain water. It also gives architectural appearance and adds to the strength of the wall. Cornice. It is…

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Comparison of Brick Masonry and Stone Masonry

Comparison of Brick Masonry and Stone Masonry,Brick masonry,Stone masonry, Masonry is the art of the construction in brick or stone. Except in dry masonry some mortar is used to bind the bricks or blocks of stones, with each other. There are in general two types of masonry, viz., Brick Masonry and Stone masonry. Brick masonry is that in which bricks are used while in stone masonry, stone blocks are used.  Comparison of Brick Masonry and Stone Masonry Generally brick masonry is cheaper than stone masonry and can be easily constructed. The minimum, thickness of wall in stone masonry can be 35 cm whereas, in brick masonry, walls of 10 cm thickness can be constructed. The brick masonry construction proceeds very quickly whereas the stone masonry construction proceeds vary slowly, as the bricks are handy whereas stones are not. Skilled masons are required for stone masonry construc­tion, whereas unskilled laymen can…

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