固废新型掺合料对骨料碱活性抑制效能研究

Comparative Study on Inhibition Effect of Solid Waste New Admixture on Alkali Activity of Aggregate

针对粉煤灰紧缺地区水电工程混凝土骨料碱活性问题,研究了采用工业固废研发的新型复合掺合料对碱骨料反应膨胀的影响,并分析了不同掺量、不同配伍组成时新型复合掺合料对碱活性抑制效能的影响,并与粉煤灰的抑制效能进行了对比。结果表明:PL新型掺合料、TL新型掺合料均可以使砂浆棒的碱骨料反应膨胀率降低,降低程度与掺合料的掺量正相关;与采用的Ⅱ级粉煤灰相比,在以14d砂浆试件膨胀降低率表征的抑制效能方面,Ⅱ级粉煤灰的抑制效能优于PL新型掺合料、PL新型掺合料优于TL新型掺合料;PL新型掺合料或TL新型掺合料的碱活性反应抑制效能会随着磷渣粉或铁矿渣粉在复合掺合料体系中质量占比的提升而提高。

Aiming at the alkali activity of concrete aggregates of hydropower projects in areas with shortage of fly ash,the influence of new composite admixtures developed from industrial solid waste on reaction expansion of alkali aggregates was studied,and the influence of new composite admixtures on alkali activity inhibition efficiency at different dosages and compositions was analyzed and compared with that of fly ash.The results show that both new PL additives and new TL additives can reduce the alkali aggregate reaction expansion rate of mortar bar,and the degree of reduction is positively related to the amount of additives.Compared with the grade II fly ash used,the inhibition efficiency of grade II fly ash is better than that of new PL additives and new PL additives than that of TL additives in terms of the characterization of the reduction rate of expansion of 14d mortar specimens.The Alkali-activity inhibition efficiency of new PL or TL additives increases with the increase of the mass proportion of phosphorus slag powder or iron ore slag powder in the composite additive system.