Optimized Compressive Strength Modeling of Mixed Aggregate in Solid Sandcrete Production

The paper presents the report of an investigation into the model development and optimization of the compressive strength of 60/40 sand/quarry dust solid sandcrete block. Quarry dust is a massive waste in quarry sites and can be combined with sand at studied ratios. The study applies the Scheffe’s optimization approach to obtain a mathematical model of the form f(xi1,xi2,xi3,,xi4), where xi are proportions of the concrete components, viz: cement, sand, quarry dust and water. Scheffe’s experimental design techniques are followed to mould various solid block samples measuring 450mm x 225mm x 150mm and tested for 28 days strength. The task involved experimentation and design, applying the second order polynomial characterization process of the simplex lattice method. The model adequacy is checked using the control factors. Finally a software is prepared to handle the design computation process to take the desired property of the mix, and generate the optimal mix ratios.