The team led by Aravinda Kumar Vasu and teammates Ragav S and Kirubakaran S participated in the four-stage competition that included awareness, ideation, business modelling and founding a start up to a jury at Anna University.

Through this project the Sona team solved the problem of discarded plastic filling up waste dumps on the city outskirts while reducing demand for natural resources like natural sand, water and raw materials for cement. Availability of salt-free water for making and curing building products too is becoming a major issue affecting the life of new structures.  

Innovative Replast Pavers and Building Blocks, built without using water and cement, use Industrial by-products like steel slag, copper slag, fly-ash, and waste plastics to replace cement.  

The process involves collection of waste plastics, shredding and heating. Molten plastic mixed with the steel slag or fly-ash along with certain admixture is then placed in the paver and brick moulds. As plastic acts as the binding material, it reduces the gaps and improves the bonding strength between aggregates. After cooling, it has to be taken out from the moulds. In this product, molten plastics act as binding agents as well as a filler with other materials. Hence, there is no need for water for making and curing the products.

As per Indian Roads Congress guidelines for the use of waste plastic in hot bituminous mixes no toxic gases are generated for temperatures up to 180⁰C. Generally, plastics start melting at 100⁰C. Hence between 100⁰C and 180⁰C, plastics can be melted and mixed with other materials. Semi-automated machines were designed for melting and mixing the plastics to make pavers and building blocks.  

The project in addition to paving the way for eco-friendly products reduces construction materials cost to half. Since no curing and drying is required the rate of production of these products is high. 

The low-cost, good quality Replast building products do not compromise the mechanical properties and durability. This alternate sustainable product could change the face of the construction industry.