Optimization of Sandrete Block based on Scheffe’s Model using Quarry Dust as Partial Replacement of River Sand

Abstract

This research work focuses on the optimization of sandcrete hollow block based on Scheffe’s model using quarry dust as partial replacement of river sand. The investigation shows that the specific gravity, uncompacted bulk density, moisture content and compacted bulk density of river sand and quarry dust are 2.71 and 2.74; 1523.8 kg/m3; 1767.86 kg/m3 and 7.89%; 1.46%; 1819.44 kg/m3 and 2005.95 kg/m3 respectively. The maximum average water absorption for hollow sandcrete blocks is 10.56% with 0.6:1:6.5 mix ratio for cement, quarry dust and river sand, which fell below 12% of the dry weight as stipulated by Nigerian Industrial Standards. The maximum average density of hollow sandcrete blocks is 1797.53 kg/m3 with 0.6375: 1: 6.1625 mix ratio which is within the threshold. Six optimization models were developed from a reduced second-degree polynomial: Ŷ=𝛽1𝑋1+𝛽2𝑋2+𝛽3𝑋3+𝛽12𝑋1𝑋2+𝛽13𝑋1𝑋3+𝛽23𝑋2𝑋3. The Optimum Experimental Strength and Model Predicted Strength correlate well with R2 of 0.93.