煅烧煤矸石粉掺合料制备及对混凝土性能影响

通过胶砂强度评价法,确定煅烧煤矸石粉掺合料最佳制备工艺条件为:煅烧温度750℃、恒温2 h、研磨3 min;在此基础上,研究煤矸石掺合料与其他掺合料复掺比例对混凝土工作性、抗压强度、抗冻性的影响。结果表明:煅烧煤矸石粉与矿粉或粉煤灰最佳复掺比例为3∶7,与粉煤灰复掺,混凝土塌落度值、7 d、28 d抗压强度高于与矿粉复掺。与粉煤灰复掺,冻融循环次数可达550次;与矿粉复掺,冻融循环次数达到500次。综合各项指标,煅烧煤矸石粉与粉煤灰的相容性优于与矿粉之间的相容性,二者复合使用,既能改善混凝土拌合物的工作性,又能保证混凝土强度。

Effect of the Preparation Process of Calcined Coal Gangue Powder Admixture on Concrete Performance

Through the method of glue sand strength evaluation, the optimum preparation conditions of the calcined coal gangue powder blending material is as follows: calcination temperature 750 ℃, constant temperature 2 h, grinding 3 min. The effects of proportion of coal gangue and other admixtures on the workability, compressive strength and frost resistance of concrete was studied on this basis. The results show that calcined coal gangue powder mixed both with ratio of 3:7, the concrete slump and compressive strength of 7 d and 28 d is higher than with mineral powder mixed when mixed with fly ash. For the resistance to freeze-thaw, the freezing-thawing resisting can reach 550 times when fly ash mixed with calcined coal gangue powder, but 500 times when mixed with slag. The mixing between fly ash and calcined coal gangue powder had a better compatibility than the slag on the basis of all indexes, not only improve the workability of concrete mixture, but also guarantee the strength.