Evaluation of production cost of bricks using clay and stone dust-cement

Abstract

This study aimed to investigate whether mixing clay soil, stone dust, and 5% cement could enhance strength, reduce water absorption, and lower production costs, without compromising the material's quality. Clay soil from near FUTA, Akure and stone dust from a quarry were used. Tests were conducted on the raw materials, including sieve analysis, moisture content, bulk density, and specific gravity. Clay soil was partially replaced with stone dust at 0% (control), 5%, 10%, 15%, 20%, and 25%, with a constant 5% cement. 288 bricks were produced, 144 air-dried and 144 fired at 1000°C. Compressive strength and water absorption tests were performed on both burnt and unburnt bricks. The results showed that for burnt bricks at 28 days, water absorption ranged from 11.11% to 20.00%, and for unburnt bricks, 3.33% to 7.69%. The compressive strength of burnt bricks increased up to 15% stone dust replacement, then decreased, while unburnt bricks showed a gradual strength reduction with increasing replacement. Both results met NIS and BS standards for normal building bricks