煤矸石掺合料的制备及对高强混凝土性能影响

摘要

Through the study of calcining temperature, grinding time and ifneness on calcined gangue-cement glue sand strength to preparate coal-gangue admixture. The effects of species and proportion of admixture and water-reducer dosage on workability and the strength of concrete was studied on this basis. The results showed that spontaneous or calcined coal gangue powder mixed with silica fume could be used to prepare ready mixed high strength-concrete. The compressive strengths of the concrete with coal gangue -silica fume at 7 d and 28 d were signiifcantly higher than that with lfy ash-silica fume. The results indicated that there was a signiifcant effect of species and dosage of admixture on the compressive strengths of high strength concrete at 7 d. With the dosage of calcined coal gangue increasing, the concrete strength increased signiifcantly. There was a signiifcant effect of species and dosage of admixture on the splitting tensile strength of concrete at 28 d. Although the slump of the concrete mixture with coal gangue-silica fume was inferior to that with lfy ash-silica fume, but it could still satisfy the requirements of ready mixed concrete.%通过研究未燃煤矸石的煅烧温度、恒温时间以及细度对煤矸石-水泥胶砂强度的影响，制备煅烧煤矸石矿物掺合料，并检验胶砂流动度。在此基础上，研究热活化煤矸石掺合料（包括煅烧和自燃煤矸石两种）与其他掺合料复掺的品种、比例以及减水剂掺量对高强混凝土工作性和强度的影响。结果表明：热活化煤矸石粉与硅灰复掺，在高效减水剂共同作用下，配制预拌高强混凝土可行。热活化煤矸石与硅灰复掺，混凝土7 d、28 d抗压强度都明显高于粉煤灰和硅灰复掺。其中掺合料复掺品种及掺量对高强混凝土7 d抗压强度影响非常显著，随着热活化煤矸石粉掺量的递增，混凝土强度明显递增。复掺品种对混凝土28 d劈拉强度影响显著。热活化煤矸石与硅灰复掺对新拌混凝土坍落度的改善不及粉煤灰与硅灰复掺，但能满足预拌混凝土大流动性的施工要求。