(558ap) Utilization of the Nanosilica Synthesis Process Generated Waste in Concrete Blocks: An Environmental Friendly Solution

Prabhat Vashistha¹, S.K. Singh², Vivek Kumar³

¹Research Scholar, Indian Institute of Technology, Roorkee, prabhat0785@gmail.com

²CSIR-Central Building Research Institute, Roorkee, sksingh_cbri@yahoo.co.in

³Associate professor, Indian Institute of Technology, Delhi, Vivekk@iitd.ac.in

The need for nanosilica in market was estimated about 3,348 kilotons in 2015. Increasing demand from the rubber industry is expected to be a main aspect for boosting market growth in light of growing automotive industry. The global market is projected to reach USD 5,140.2 million by 2025, growing at a CAGR of 7.6% from 2016-2025. This growth is expected to be driven by growing use of nanosilica as an additive in various application segments such as concrete, rubber and others. At the same time it is also necessary to manage the waste generated through the process of nanosilica synthesis. In this paper, waste generated by nanosilica synthesis from fly ash is utilized. Nanosilica was synthesized with the alkali treatment of ash and acid precipitation. The remainings of fly ash after extraction of nanosilica from it was characterized for composition, morphology and size. This waste was used in cement based concrete for the replacement of fine aggregates in the proportion of 10, 20, 30, 40 and 50% by weight. Concrete blocks were evaluated for compressive strength after 7 and 28 days of curing. Concrete blocks produced with the replacement of fine aggregate with 30% attained up same compressive strength in comparison to the blocks without waste.

Keywords: solid waste, Fly Ash, Nano silica, Concrete