Scientists have developed technology that addresses two important issues: conserving extracted raw material resources and reducing emissions.
Researchers have developed a technology to produce energy-efficient walling materials using construction and demolition (C&D) waste and alkali-activated binders, the Science and Technology Ministry said Thursday.
Called low carbon bricks, they do not require high temperature firing, and avoid the use of high energy materials such as Portland cement. The technology will also solve the disposal problems associated with C&D waste mitigation.
Conventionally, building envelopes consist of masonry walls constructed with fired clay bricks, concrete blocks, hollow clay blocks, fly ash bricks, lightweight blocks, etc.
Envelopes spend energy during their production, thus generating carbon emissions, and consume extracted raw material resources which lead to unsustainable constructions.
Masonry units are made either through the firing process or using high energy binders or embedded carbon such as Portland cement.
The annual consumption of bricks and blocks in India is around 900 million tons. In addition, the construction industry generates huge amounts (70-100 million tonnes per year) of construction and demolition waste (CDW).
In order to promote sustainable construction, two important issues must be addressed when manufacturing masonry units: conserving the resources of extracted raw materials and reducing emissions.
Moving towards this goal, scientists at the Indian Institute of Science (IISc) have developed a technology to produce alkali-activated bricks or blocks using fly ash and kiln slag.
The team of researchers developed bricks with low embedded carbon content from CDW waste through an alkaline activation process using fly ash and crushed slag and characterizing the thermal, structural and durability characteristics of low-carbon bricks. carbon content and their masonry.
After checking the physicochemical and compaction characteristics of the CDW, the optimal mixing ratios of the materials were obtained, then the production process evolved to produce low carbon bricks. Based on the optimum proportions of binder, compressed bricks were produced. The bricks have been examined for their technical characteristics.
The main beneficiary of this development undertaken by IISc Bangalore, with funding from the Department of Science and Technology, is the construction industry in general and the building sector in particular. This technology will also alleviate the disposal problems associated with C&D waste.
âA start-up has been registered which will be operational within 6 to 9 months to manufacture low-C bricks and blocks with technical assistance from IISc.
“The start-up unit will act as a technology diffusion unit through training, capacity building and provision of technical know-how to establish such business units across India,” said note Professor BV Venkatarama Reddy, IISc Bangalore.