Author: haroonkhan

Prefabricated RCC lintels can be used conveniently over windows, door openings and passage openings. Precast lintels indirectly accelerate the speed of construction as the curing period is eliminated. Precast RCC lintels are preferred for small spaces up to 2 m (Fig. 9.3) and they are usually cast in wooden moulds and cured well in advance.…

Different types of precast concrete units are discussed below. 9.6.1 Hollow Concrete Blocks Hollow concrete blocks are manufactured in various shapes and sizes. Blocks of concrete are moulded in a machine. Details of standard size blocks, which are used for different works, are given below: The face thickness of blocks is maintained as 5 cm…

Processes of manufacture comprise a main process supplemented by an auxiliary process and a subsidiary process (Sharma, 1988). 1. Main Process The activities involved in the main process are given below: 2. Auxiliary Process The activities affecting the successful functioning of the main process are as follows: 3. Subsidiary Process The activities that help to…

In this case the components are manufactured at the site or as near to the site as possible. This type of manufacturing is employed for specific jobs that last for a short span of time. Locally available labour force is as for as possible used and the equipment and moulds are rented. Generally, the work…

Factory prefabrication is adopted in a centrally located plant for the manufacture of standardized components on a long-term basis. The production unit has to work throughout the year preferably under a closed shed to avoid the effects of seasonal variations. The feasibility of the introduction of the latest manufacturing technique should be considered. Further, there…

Crucial factors that are to be considered for effective production and supply of precast concrete components are: Manufacture of precast concrete units can be done in a centrally located factory, or in a site where a precasting yard is set up at or near the site of work.

The preferred dimensions for different elements of a building considering the basic module are as follows: 1. Flooring and Roofing Scheme Precast slabs or other precast structural flooring units: 2. Beams 3. Columns 4. Walls 5. Staircase Width – Nominal width shall be in multiples of 1 M 6. Lintels 7. Sunshades/Chajja Projections Normally acceptable…

Modular Co-ordination For prefab construction and for the precast elements, modular co-ordination has to be followed. In this case, some basic module has to be adopted for general application to buildings and their components. The value of the basic module chosen is 100 mm for maximum flexibility and convenience. The symbol used for the basic…

There are certain aspects that discourage the use of precast concrete units under the following conditions:

Precast concrete has several advantages over cast-in-situ concrete: