煅烧煤矸石粉对混凝土工作性和强度的影响

Effect of Calcined Coal Gangue Powder on Workability and Strength of Concrete

将小于5mm方孔筛的未燃煤矸石颗粒以不同温度、不同粉磨时间为间隔取点煅烧及粉磨,分别以30%取代水泥,以胶砂强度较高者确定煤矸石最佳的煅烧温度和粉磨时间。在此基础上采用正交试验,研究煅烧煤矸石粉、粉煤灰和矿粉复掺的相容性及对混凝土工作性和强度的影响。结果表明,清河门矿未燃煤矸石最佳煅烧温度750℃、最佳粉磨时间3min;煅烧煤矸石粉、粉煤灰和矿粉之间的不同品种复掺对混凝土拌合物工作性影响特别显著,对7d强度影响显著,对28d强度影响不明显。而掺量比例对工作性和28d强度影响不明显,对7d强度有一定影响。煅烧煤矸石粉与粉煤灰复掺的相容性最好,二者复合使用,既能改善混凝土拌合物工作性,又能保证混凝土7d和28d强度。

Unburned coal gangue particles of which particle size was less than 5 mm square sieve,was were calcined and ground at interval of different temperatures and different grinding time,and the The optimal calcining temperature and grinding time were determined by the highest strength of cement mortar with in which 30% cement was replaced by the calcined coal gangue. On this basis,using orthogonal design was adopt to study the consistency of calcined coal gangue powder,slag and fly ash compound and the effect of it on workability and strength of concrete. The results showed that the optimal of calcination temperature of Qing He-men coal gangue was is 750 ℃ and the optimal of grinding time was is 3 min.The compound admixture of admixtures including calcined coal gangue powder,slag and fly ash had has a very significant effect on workability of concrete,as well as on strength for 7 d of 7 d concrete,but not obvious on strength for 28 d of concrete at 28 d. While the compound proportion has not an obvious effect on workability and strength for 28 d of concrete at 28 d,but has a certain the effect on strength for 7 d concrete is relatively obvious. Combination of calcined coal gangue powder and fly ash compound using had showed the best consistency. They could not only improve both the workability of fresh mixture and but also and guarantee the 7 and 28 d strength of hardened concrete 7 d and 28 d of are greatly improved.