Relevance and Assessment of Fly Ash-Based Sintered Aggregate in the Design of Bricks, Blocks and Concrete

Abstract

This paper presents the investigation carried out to evaluate the relevance and assessment of bricks, blocks and concrete using sintered aggregate. The main advantages regarding the use of lightweight aggregate concrete in construction are primarily to reduce the self-weight structures besides attaining better thermal insulation performance. Materials can thus be used for producing lightweight solid or hollow concrete blocks as well as bricks for walling purpose. The granular sintered fly ash is found to be best with use of powder fly ash while making bricks and blocks. For making concrete, mixes have been prepared with 20, 30 and 40% replacement of natural aggregate with sintered fly ash aggregate, keeping all in the aggregate grading was unchanged. Concrete with sintered fly ash aggregates up to 40% replacement by volume. The percentage increase of fly ash aggregate decreases the strength of concrete but these are well above the target strength. Research is carried out to evaluate the aggregate samples for evaluations of specific gravity, water absorption, bulk density, particle size, mechanical properties and soundness of aggregate as per relevant Indian standards to assess its suitability in use of sintered aggregate in making bricks and blocks, mixes for concrete with sintered aggregate. To reduce the drying shrinkage in brick, we can use calcinated gypsum instead of cement. The presence of lime in the absence of cement increases the drying shrinkage in brick.