矿渣微细粉对水泥基材料抗酸雨侵蚀特性研究

模拟中国硫酸型酸雨情况,以普通硅酸盐水泥空白砂浆为参比体系,研究采用矿渣微细粉对于改善混凝土抗酸雨性能的影响.分别从质量损失率、抗压强度、抗折强度和微观显微分析手段研究了各项性能变化规律.研究结果表明:在试验条件下矿渣微细粉存在最佳掺量区间,以20%~30%为最佳.当掺量超过30%时,砂浆不能生成足够的C-S-H凝胶,结构较疏松,内部微裂纹未被新的水化产物填充密实,H+和SO42-更容易进入浆体内部,导致更严重的腐蚀破坏;而当掺量少于20%时,火山灰效应发挥不明显,也不能促进砂浆抵御酸雨的侵蚀.在模拟酸雨环境中浸泡98 d后.25%矿渣掺量的砂浆质量损失率最小仅为-38.2‰.且后期下降趋势最为平缓;对于抗压强度和抗折强度,在酸雨侵蚀条件下分别呈现不同的变化趋势,对于抗压强度的强化效果应控制矿粉的掺量不小于25%,而对于抗折强度,则应控 .制掺量不大于30%.综合考虑抗压强度和抗折强度,25%掺量最能强化砂浆抗酸雨侵蚀的性能;在SEM显微分析中可以观察到,矿粉砂浆较空白砂浆结构密实,微裂纹少.矿粉使水泥浆体的孔隙率明显下降,强化了集料界面黏结力,并减少了最大孔径的尺寸,大幅度提高混凝土的密实度,也就能更好地抵御酸雨离子的侵入.

Anti-acid rain erosion performance of cement materials of slag micro-fine powders

The chinese sulfate types acid rain's condition is simulated,taking ordinary portland cement blank mortar to be the contrastive system;using slag micro-fine powders to improve the concrete property of resisting acid rain is researched;the law of the properties are studied through mass loss rate,compressive strength loss,flexural strength loss and SEM microanalysis.The results show that,in our experiment's condition,slag micro-fine powders existed the best doping interval,taking for 20%~30% as the best mixin...