基于正交试验的活性粉末混凝土力学性能及耐久性研究

Mechanical Properties and Durability of Reactive Power Concrete Based on Orthogonal Experimental

通过正交试验设计了18组不同配合比的活性粉末混凝土(RPC),在常温养护制度下对其进行抗压强度和抗折强度试验研究,分析了砂胶比、水胶比、钢纤维掺量等因素对RPC力学性能的影响,考察了RPC破坏过程及形态。基于力学性能最优试验组,对该配合比进行优化,然后进行了抗冻融循环试验和抗硫酸盐侵蚀试验研究。试验结果表明:水胶比和钢纤维含量对RPC抗折和抗压强度影响显著,钢纤维含量过高导致RPC拌合物流动性较差,亦不经济,建议钢纤维体积含量控制在1.5%左右。RPC经冻融循环次数达150次时,其相对动弹模量为95.2%,质量损失忽略不计;经硫酸盐溶液侵泡的RPC试块强度相比在清水侵泡中提高了16.2%,RPC的抗硫酸盐侵蚀系数为116.5%。

According to the orthogonal design method, 18 mix proportions of RPC were designed. The mechanical properties such as compressive strength and flexural strength were tested at the room temperature curing. The failure process and pattern were observed. The influence of the water-binder ratio, the steel fiber content on mechanical properties of RPC was analyzed. Based on the mix proportion of the optimal mechanical properties in the orthogonal test, the durability such as the resistance of freezing- thawing cycle and sulfate were conducted. Tests show that the compressive strength and flexural strength were significantly effected by the water-binder ratio and the steel fiber content. The steel fiber content is too high to economic, resulting the fluidity of the mixture was poor and suggesting that the steel fiber volume content was controlled at about 1.5%. When the number of freezing-thawing cycles was 150 times, the relative dynamic modulus of RPC was 95.2% and the mass loss was very little. The strength of RPC immersed in the sulfate solution was increased by 16.2%, compared with specimen immersed in the water. The RPC resistance coefficient of sulfate attack was 116.5%.