Optimization of Multi-additives for Expansive Soil Improvement Using Response Surface Methodology

Central composite design, a type of response surface methodology (RSM), was combined with Derringer and Suich desirability function approach (DFA) in this study to optimize multi-additives for expansive soil improvement. The additives, which ranged from 2 to 8% for Ordinary Portland cement (CM) and 0–20% for both sawdust ash (SDA) and quarry dust (QD), were all added by air-dried weight of the expansive soil. The soil properties evaluated as the...