Optimizing the Mix Design of Cementitious Composites Incorporating Volcanic Ash by Taguchi-TOPSIS Method

– This research investigates the potential of using volcanic ash (VA) as a partial replacement for cement in construction applications that require superior early-age properties. The study employs Taguchi methodology to optimize the cementitious composites by varying key factors, including binder content, water-to-binder ratio, dune sand substitution rate of natural sand, VA substitution rate of cement, and superplasticizer (SP) dosage. As each factor had four corresponding levels, an L16 orthogonal array was developed. Testing included the flow, setting time, and 1-day compressive strength. The Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) was employed to optimize for the three factors simultaneously. The results indicate that the optimum mix consisted of a binder content of 400 kg/m³, a water-to-binder ratio of 0.5, a dune sand substitution of 20%, a VA substitution of 20%, and an SP dosage of 0.75%. Accordingly, the optimum mix achieved a flow of 115 mm, a final setting time of 350 min, and a 1-day compressive strength of 18.1 MPa. This study demonstrates the optimum use of volcanic ash as a sustainable alternative to cement in construction applications with time-critical requirements.