Category: Concrete

Testing of fresh and hardened concrete is important in concrete construction. Tests are conducted on fresh concrete to check the workability of concrete, and on hardened concrete to determine the strength, creep effects, durability, etc.

Applied finish is the exterior application of rendering made on concrete structures. In this case the concrete surface is finished and kept wet after which mortar (1:3) is applied. The desired finish is then given to the mortar. Sometimes the rendering applied on a wall is pressed with a sponge. On repeating this process, the…

This is a commonly used method of surface finishing. It is important for a residential floor to be smooth. To obtain a smooth finish, first the proportioning of mix should be appropriate. The finishing of surface should be at the same rate as that of placing of concrete. Attention must be paid to the extent…

Concrete maintains the shape of formwork, i.e., centering work. Thus, keeping the required shape through formwork, viz., undulated fashionable shapes, V-shaped finishes, plain surfaces, etc., any pleasing surface can be obtained. The imaginative ideas of architects may be implemented by a careful formation of concrete surface. A properly made out formwork can give a very…

Finishing is the last stage in concrete construction. After casting of a concrete, the concrete does not offer a pleasant architectural appearance. In some cases like beams, finishing may not be needed. For a residential building, airport or road pavement and culvert and bridges, finishing is a must. Now-a-days, the centering materials are so made…

The following methods of curing are adopted depending on the type of work: Direct Curing In this method water is directly applied to the surface of curing. In this process, the surface is continuously cured by stagnating water, or using moist gunny bags, straws, etc. These methods are used for horizontal surfaces. Vertical surfaces can…

Compaction of concrete has to be done as early as possible after placing the concrete in place. The purpose of compaction is to expel air and bring the particles closer so as to reduce the void and make the concrete denser. This increased density will give higher strength and make the concrete impermeable. Over-compaction leads…

The mixed concrete should be conveyed to the concreting yard as early as possible but within the initial setting time of the cement. The choice of conveyance depends on several factors, viz., nature of work, distance from the mixing place to the construction site, height to be lifted, type of cement, etc. During the transit…

Mixing of concrete may be done by hand or by a machine. Mixing should be done thoroughly so that the ingredients are uniformly distributed, and this can be judged by uniform colour and the consistency of concrete. On a clean, hard and water-tight platform cement and sand are mixed dry using shovels until the mixture…

In this batching method, two units of measurements are employed: liquids are measured in litres and solids in cubic metres. That is all ingredients, viz., water, cement, sand and coarse aggregates are measured in litres, while the end-product concrete is measured in cubic metres. In volume batching, other quantities are measured keeping cement as the…