Sustainability-driven model for predicting compressive strength in concrete structures

Abstract

Over the past few decades, enhancing the sustainability of concrete structures has become a worldwide necessity. This study proposes a mathematical model for predicting compressive strength (CS), aiming to further the objective of designing sustainable concretes incorporating silica-fume as a partial cementing replacement material. The article outlines the formulation, calibration, evaluation and validation of the proposed model. Various factors related to concrete mixture and age were considered in the formulation of the CS model, which employed multiple sub-models including a cement hydration model that considers cement chemical composition and hydration rate, along with other factors like aggregate packing density, capillary porosity, air pores, standard cement strength, paste-to-aggregate bond strength and presence of supplementary cementing materials. An experimental program consisting of 10 different concrete mixtures was designed to calibrate and evaluate the model. The model was then validated using databases from multiple literature sources, which consisted of 50 data points with diverse materials and mixture proportions, to test its accuracy and generalization capability. Results show that the proposed model closely matches the experimental data and has no sign of anomalies or distinct trends. The model’s coefficient of determination and standard error are 0.97 and 4.0 MPa, respectively. Moreover, model validation demonstrates high predictability and generalization capability, with a corresponding coefficient of determination and standard error of 0.93 and 4.4 MPa, respectively. Overall, this research suggests that the proposed mathematical model is a reliable tool to predict the CS of sustainable concretes that utilize silica-fume as a partial cementing replacement material.

Keywords

• Concrete
• sustainability
• compressive strength
• hydration
• packing density
• porosity