An Innovative Material with Strong Frost Resistance—Concrete Containing Dolomite Powder

作者：Xin Zhang, Yumei Luo, Wu Yao · 发表于：Materials · 年份：2022 · DOI：10.3390/ma15051721 · 被引用次数：18 · 研究领域：Concrete and Cement Materials Research、Innovative concrete reinforcement materials、Magnesium Oxide Properties and Applications

The effects of dolomite powder on the freeze-thaw resistance of C30 and C45 concrete were investigated in this manuscript. Scanning electron microscopy (SEM), the electric flux method, and a freeze-thaw cycle testing machine were used to determine the morphology, chloride penetration resistance, mass loss rate, and relative dynamic elastic modulus (Er) of concrete incorporating dolomite powder. Concrete's freeze-thaw resistance improved as the dosage of dolomite powder was increased. After 300 cycles, the mass loss rates of reference specimens of C30 and C45 concrete were 6.71% and 0.14%, respectively, whereas the mass loss rates of C30 and C45 concrete in the presence of dolomite powder at a 50% replacement level were 5.81% and 0.13%, respectively. After 225 cycles, the Er of C30 concrete was 42.57% and 48.56% in the case of dolomite powder at 0 and 50% replacement levels, respectively. Meanwhile, after 300 cycles, the Er of C45 concrete was 67.54% and 71.50% in the case of dolomite powder at 0 and 50% replacement levels, respectively. Accordingly, the structure of dolomite-containing cement-based materials became more compact. Based on the Weibull distribution, a damage model for concrete containing dolomite powder was proposed. It established that concrete treated with dolomite powder had a lower degree of damage than reference specimens when subjected to the same freeze-thaw conditions.