Hydration-based integrated modeling of the strength, carbon emissions, and abrasion resistance of cement-natural zeolite concrete

초록

Although concrete incorporating natural zeolite powder has been extensively studied, performance prediction models for natural zeolite powder-containing concrete based on hydration mechanisms remain scarce. To address the lack of hydration models and hydration-based performance predictions for natural zeolite powder concrete, a binary cement-natural zeolite powder concrete hydration model is proposed in this study. On the basis of the proposed hydration model, the reaction degrees of both zeolite powder and cement are predicted. Increasing the level of zeolite replacement from 15% to 25% decreases the reaction degree from 0.559 to 0.453 (w/b ratio = 0.30) and from 0.537 to 0.431 (w/b ratio = 0.25), representing a reduction of approximately 19-20%. In comparison, decreasing the water-to-binder ratio from 0.30 to 0.25 at a fixed zeolite replacement level yields only a 4-5% decrease. On the basis of the reaction degrees of zeolite powder and cement, linear strength models are developed to predict the compressive strength and the flexural strength. The predicted compressive and flexural strengths are consistent with the experimental results, with correlation coefficients of 0.953 and 0.950, respectively. Carbon emissions per unit volume are calculated from the mixture proportions and sustainability database and then converted into carbon emissions per unit strength on the basis of the predicted compressive strength. The results reveal that the unit-strength carbon emissions decrease with decreasing water-to-binder ratio and increasing zeolite powder replacement level. Furthermore, on the basis of strength- and abrasionrelated experimental parameters, an abrasion resistance prediction model for zeolite powder concrete is proposed. In terms of the Cantabro loss and wear depth, the correlation coefficients between the predicted and experimental results are 0.871 and 0.927, respectively. The proposed hydration, strength, carbon emission, and abrasion resistance models are mechanistically based, and their coefficients remain constant within the considered ranges of zeolite replacement levels (0-25%) and water-to-binder ratios (0.25-0.46). Overall, the integrated hydration degree-based prediction framework developed in this study guides the engineering application of low-carbon zeolite concrete and promotes the achievement of carbon neutrality in the concrete industry.

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