在深入分析混凝土冻融破坏机理及其影响因素的基础上,提出在混凝土中双掺硅粉和粉煤灰的方法,并按有关规范要求进行普通混凝土与双掺混凝土抗冻性能的对比试验。试验结果表明:双掺混凝土因基于“等量替换法”用硅粉和粉煤灰替换了一部分水泥,减小了水泥用量和增大了水灰比,故双掺混凝土的强度和弹性模量均明显低于普通混凝土,但减水剂的使用降低了水胶比,使双掺混凝土的抗冻性能优于普通混凝土。
A method of adding silica fume and fly ash to the concrete was presented based on investigating concrete freeze-thaw mechanism and its influential factors .The frost resistance testing of both ordinary concrete and the concrete mixed with silica fume and fly ash was conducted .The results showed that both the compressive strength and elastic modulus of the concrete mixed with silica fume and fly ash were lower than those of ordinary one due to part of cement replaced by silicon powder and fly ash based on the equivalent substitution method , in that case , the content of cement was reduced and the water-cement ratio was increased .However, the use of water reducing agent reduced the ratio of water to cementitious material , which leaded to a better frost resistance of double mixing concrete than that of ordinary concrete .