Why to go for Building Construction with precast?
There are many benefits over the conventional construction. The elegant benefits are high speed, good quality and neat construction with less wastage. Today precast concrete industry is highly
customer focused. Many innovative technologies have been adopted and practiced in the industry. Thermal, acoustic, seismic resistant technologies and beautiful pleasing architectural precast facades to the building are already available and practiced in many countries. Precast technology can be more popularized in Indian construction industry with such innovative products and construction methods.
Comparison of precast construction vs conventional building:
In precast the wastage is less than 1% as the majority of concrete work is done in factory and concrete is batched exactly according to the requirement.
In convention system wastage is usually 3-5%.
In precast pretension slab are used , the entire load calculated is taken care by the strand itself and the rest of the reinforcement is just a welded mesh. In general the steel quantity is less than 1% of concrete volume. Wastage will be well controlled and even the generated wastage will be used smaller precast components. In general the wastage will be 1-1.5%. In general steel quantity will be 1 to 1.5% of the concrete volume. wastage will be much higher comparatively , and it will be 3-5%.
Steel mould :
One time steel mould has to be fabricated and it shall be used for more than 500 cycles and most of the time it will be multiples of 500 only. After the usage also the moulds shall be scraped which will generate at least 50 % of fund invested. Has credit point for Green Building.
Its not applicable in convention system.
In precast very minimal form-work is required.
In convention system form-work are used for about 5 cycles and it has to be scraped. Against Green Building as it consumes more timber woods.
Production Yard :
In precast system separate yard is required
In convention system rebar yard and formwork yard is required.
In precast construction very minimal scaffold work required.
In convention system full-fledged scaffolding is required.
In precast system Logistic required for lifting and transporting components such as hydraulic crane, trailer, workers etc.
In convention system less logistic required as most of the time manpower is used to lifting the material.
In precast suitable cranes have to be used for lifting , storage and erection of components.
In convention system one crane is required for lifting materials.
In precast construction less manpower required at site and nominal manpower required at production yard.
In convention system huge manpower is required.
In precast the quality is 100% as its factory product.
In convention system quality is achieved about 75%.
In precast 90 % has safe and clean environment as most of the concrete, rebar and shuttering works will be handled separately at the yard.
In convention system only 50-60% clean environment is achieved.
Indirect cost :
In precast big savings as, Ceiling plastering is not required when precast slab are used. Brick wall and plastering is not required when precast slab are used. Moreover there is huge time savings, which means overheads, rent and other admin charges been saved and interest earned due to early payment by clients or early production for clients benefits them as well.
In convention system the time delay has become unavoidable in most of the projects, which leads to additional overhead and other expenses. Most of the projects suffers about 20 to 30% run off from the budget.