低掺量矿物掺合料对C30喷射混凝土性能的影响

Effect of Mineral Admixture with Low Content on the Performance of Sprayed Concrete

对比纯水泥体系,文章从净浆凝结时间、砂浆早期强度、混凝土力学强度与干燥收缩性能等方面探究了低掺量矿物掺合料对C30喷射混凝土性能的影响,结果表明:矿物掺合料以低掺量形式单掺或复掺会造成喷射混凝土的凝结时间延长,同掺量下粉煤灰对体系的缓凝效果要强于粒化高炉矿渣粉;喷射混凝土的早期力学强度及干燥收缩性能受低掺量矿物掺合料的影响而有所劣化,但通过火山灰水化反应及微骨料填充效应提高了喷射混凝土的后期强度,有利于满足C30强度等级的喷射混凝土力学性能要求。

Compared to pure cement group, the effect of effect of mineral admixture with low content on the performance of sprayed concrete is investigated via cement slurry setting time, mortar early strength,mechanical strength and drying shrinkage behavior of sprayed concrete. Results shown that the coagulation performance of sprayed concrete was retarded with mineral admixture introduced, singly or jointly. Such retarded effect of fly ash was stronger than that with granulated blast furnace slag. On the other hand, when mineral admixtures were used, the early strength and drying shrinkage values of sprayed concrete could be deteriorated. But the long-term strength was enhanced due to the pozzolanic reaction and micro-aggregate filling effect, induced by the mineral admixtures, thus was beneficial for the mechanical strength demand of C30 sprayed concrete.