Researchers from the Indian Institute of Science (IISc), Bengaluru have developed low carbon bricks that are made from construction and demolition (C & D) waste. These bricks do not require high- temperature firing, and avoid the use of high- energy materials such as Portland cement, said Ministry of Science And Technology on Thursday.
The technology producing energy- efficient walling materials will also solve the disposal problems associated with C & D waste mitigation. Conventionally, building envelopes consist of masonry walls built with burnt clay bricks, concrete blocks, hollow clay blocks, fly ash bricks, lightweight blocks, and so on. Scientists have developed this technology for alkali- activated bricks or blocks by utilising fly ash and furnace slag.
According to the Ministry, the annual consumption of bricks and blocks in India is about 900 million tonnes. Besides, the construction industry generates vast amounts (70-100 million tonnes per annum) of construction and demolition waste (CDW). Conserving mined raw material resources and emission reduction should be addressed while manufacturing the masonry units.
The discovered technology also aims to mitigate the disposal problems associated with the C&D wastes. The process of mixing materials like fly ash and ground slag through alkali activation in optimum ratios were obtained after ascertaining the physic-chemical and compaction characteristics of CDW. Based on this optimum binder proportions, the compressed bricks were manufactured
B.V Vnkatarama Reddy, professor at IISc said, “A start- up has been registered which will be functional within 6-9 months to manufacture low-C bricks and blocks with IISc’s technical help.”
He added, “The start- up unit will act as technology dissemination unit through training, capacity building, and providing technical know- how for establishing such commercial units across India.”