Advance Technique of Precast Concrete Production

The rate of infrastructure development growth and the necessity of producing better quality construction material demand shifting from conventional method of the production to certain advanced techniques. Water–cement ratio plays an important role in the quality of concrete product. High water–cement ratio produces lower strength concrete and vice versa. Normally, water–cement ratio required for hydration of cement is as low as 0.23 as compared to what is being practised during actual mixing considering the workability factor. Concept of extracting water after mixing and filling the mould can yield a higher strength. One such technique of precast concrete production is the “wet pressing”, in which wet concrete is pressed within the moulds using hydraulic pressure to expel out the excess water present in the concrete. Pressing time generally varies from 10 to 30 s based on the quality of materials used and quantity of water added. Pressed products are then immediately lifted and stacked in the shade for overnight curing. These products are then cured only for 3 days by sprinkling water. The study focuses on wet pressing technique of precast concrete production and comparison of products produced by this technique and old conventional methods. Wet pressed products provide better compressive strength, hardness, surface finish, durability and also reduce permeability and curing time. Method also proves to be faster and economical.