softwareng

Category: 5. Concrete

  • walls Formwork

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    Ibrahim
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    Wall formwork consists of sheets, studs, ties and braces. Sheets are supported by vertical studs and horizontal wales. Ties are provided to maintain the distance between the sheets and to resist the spalling action of the concrete. Small pieces of wood called spacers can be used and should be removed when the concrete reaches this…

  • Mixing by using machines

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    Ibrahim
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    Concrete mixing for reinforced concrete work and medium or large scale concrete work is always done by machine. Machine mixing is not only efficient and fast but also economical when the quantity of concrete is high. Concrete mixers can be classified as batch mixers and continuous mixers. Batch mixers prepare concrete batch by batch at…

  • Mixing by using hands

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    Ibrahim
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    For small-scale non-critical concrete works, hand-mixing is practiced. Since the mixing cannot be complete and efficient, 10 percent more cement must be added to compensate for the inferior concrete produced by this method. An impervious concrete or brick floor of sufficient size to pick up a bag of cement should be handled. Spread measured amounts…

  • Concrete Mixing

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    Ibrahim
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    Thorough mixing of materials is essential to produce homogeneous concrete. Mixing should ensure that the mass is uniform, uniform in color and consistency. Two methods are adopted for mixing concrete. HandshakeMechanical blending

  • Factors affecting concrete

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    Ibrahim
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    The main factors affecting the workability of concrete are given below. Water contentMix the proportions.The size of collections Use of compoundsForm of CollectionsClassification of Collections

  • Concrete Slump test

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    Ibrahim
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    Slump test is done to assess the workability of concrete. It does not measure all factors contributing to workability, nor is it always representative of concrete placement. However, it is easily used as a control test and gives an indication of the uniformity of the concrete from batch to batch. The apparatus for conducting the…

  • Concrete Durability

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    Ibrahim
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    Concrete must be able to withstand the forces of cracking due to natural and chemical causes. Durability of concrete can be increased by using good quality materials, adopting optimum water to cement ratio, using dense grade aggregates, careful mixing and compaction and proper curing.

  • Concrete Strength

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    Ibrahim
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    The concrete must be strong enough to withstand the pressure exerted on it with the required factor of safety. Concrete strength is measured in N/mm2 as mentioned earlier and is the ultimate compressive strength of 15 cm cubes after 28 days of curing (sometimes 7 days of curing strength is also known). The tensile strength…

  • Concrete properties

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    Ibrahim
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    Cement concrete has the following important properties: It has a high compressive strength. It is corrosion free and has no appreciable effect of environmental agents.It provides a hard surface that is able to resist abrasion.It is more economical than steel, as sand and coarse aggregates, which are the bulk of concrete, are generally available at…

  • Cement Water Ratio

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    Ibrahim
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    Cement and water are the only two chemically active elements in concrete. By their combination they form a glue-like binder paste, which surrounds and coats the particles of the inert mineral aggregates, sets and upon hardening binds the entire product into a composite mass. Next only to cement, water is the most important element in…