Strength investigation of tannic acid-modified cement composites using experimental and machine learning approaches

The application of tannic acid (TA) as reinforcement material in cement composites can effectively improve its sustainable development. Nevertheless, the efficacy of TA can be influenced by multiple factors, thereby impeding its practical utilization. This study primarily examines the effects of curing regimes on mechanical properties. It is found that the optimal condition is achieved at 90 degree celsius water curing. Under this regime, the addition of 0.025% TA results in a notable enhancement of 34.6% in flexural strength and 11.4% in compressive strength at 3 days. Then, this study establishes four models - RF, XGB, SVR, and ANN - to predict the compressive strength of TA-modified cement composites. The outcomes highlight that the XGB model has superior accuracy and generalization capability. It achieves a high R2 of 0.92 on the test set and an average R2 of 0.83 in a 10-fold cross-validation. Furthermore, the SHapley Additive exPlanations analysis reveals that TA ranks as the third most significant influencing factor, following the age and water content of the composites. And variables like age, nano silica, silica fume, and TA demonstrate positive correlations. They contribute positively to the development of compressive strength of the materials.