Advanced modeling of compressive strength in silica-modified oil well cement: impact of silicate, aluminate, and hydraulic moduli

This study explores the effect of cement chemical composition on the compressive strength (CS) of pure cement, cement modified with Nano Silica (NS), and Silica Fume (SF) across various mix proportions, curing times, and temperatures. Three new parameters, Silicate Modulus (SM), Aluminate Modulus (AM), and Hydraulic Modulus (HM), were introduced to evaluate cement composition’s impact on CS. SM combines SiO₂, Al₂O₃, and Fe₂O₃; AM integrates Al₂O₃ and Fe₂O₃; and HM includes CaO, SiO₂, Al₂O₃, and Fe₂O₃. Using 355 datasets, two mathematical models, Cubic (CUB) and linear and inverse (L&I), predicted CS, considering factors like cement composition, water-to-binder ratio, NS and SF content, curing time, and temperature. Statistical tools such as R2, RMSE, MAE, and SI validated model accuracy. The study assessed three scenarios: (1) multi-variate analysis of individual cement oxides; (2) bi-variate analysis using SM and AM, and (3) mono-variate analysis using HM. Introducing SM, AM, and HM improved model accuracy and reduced input parameters. Optimal NS and SF replacement percentages were 4.64% and 14.6%, respectively. SM, AM, and HM optimal values were 2.62, 1.38, and 2.21. Although initial costs increase with these replacements, they offer long-term benefits and align with sustainable construction practices.