煤矸石掺合料的制备及对混凝土碱-骨料反应影响

Preparation and Effect of Coal-gangue Admixture on Alkali-aggregate Reaction of Concrete

通过强度评价法,研究了煅烧温度、恒温时间及冷却方式三种热处理技术对未燃煤矸石活性的影响,并将制备的煤矸石掺合料与粉煤灰、矿粉进行了性能对比。在此基础上,通过胶砂流动度和快速砂浆棒试验,研究了煤矸石掺和料的细度、掺量对其稠度和碱-骨料反应的影响。试验结果表明:机械和热活化的煤矸石粉具有微集料和活性效应,对拌合物稠度有一定的改善作用,对混凝土膨胀有一定的抑制作用,其中细度比掺量影响的权重大。当地煤矸石在750℃下煅烧3 h、细度达到1150 m2/kg且掺量控制在5%时,煤矸石掺和料对工作性的改善,以及混凝土碱-骨料反应膨胀抑制效果最好。

The effects of calcination temperature, constant temperature time and cooling mode on the activity of unburned coal-gangue were studied by strength evaluation method, and the coal-gangue admixture was prepared and compared with fly ash and slag on performance. On this basis, the influence of fineness and content of coal-gangue admixture on mortar consistency and alkali-aggregate reaction was studied by its mortar fluidity and accelerated mortar bar test. The results show that coal-gangue powder with mechanical and thermal activation has the effect on micro-aggregate and activity, which can improve the consistency of the mixture and inhibit the expansion of the concrete, and the inhibitory effect of fineness is more obvious. The work-ability of concrete with the local coal-gangue admixture is improved and the inhibition of alkali-aggregate reaction gets the best effect, when the local coal-gangue calcined at 750 ℃ for 3 h, the fineness is 1150 m2/kg and the content is control in 5%.