PL复合掺合料对骨料碱活性的抑制及孔溶液分析

The Inhibiting of PL Compound Mineral Additive on Alkali Aggregate Reaction and Analysis of Its Pore Solution

磷渣粉/石灰石粉复合掺合料(简称PL掺合料)作为替代粉煤灰的一种新型掺合料,其主要物理力学性能与粉煤灰接近,但其对于混凝土骨料的碱活性抑制效果尚需进一步研究。本工作采用石英砂作为活性骨料,在保证有效碱含量相同的前提下,对比了水泥、水泥+粉煤灰、水泥+PL掺合料等砂浆试件的砂浆棒膨胀率,并对38℃水养条件下长龄期试件的孔溶液进行跟踪测量。结果表明,合适掺量的PL掺合料可有效抑制砂浆膨胀率,并显著降低活性骨料浆体孔溶液中碱离子浓度及pH值,从而达到抑制碱骨料反应的效果。

As an alternative additive,phosphorus slag and lime stone powder compound mineral additives(Abb.PL)have similar physical and mechanical properties as fly ash,however,the inhibiting effect on alkali aggregate reaction need more study work.In this work,quartz sand was applied as reactive aggregate.In the case of the same available alkali content,some mortar specimens containing cement,cement and fly ash,cement and PL were tested respectively for comparing the expansion rate,and the pore solution were analyzed from long term mortars under water curing condition of 38℃.The result indicated that,the proper dosage of PL could decrease the expansion rate and reduce the alkalinity and pH of the pore solution of active aggregate paste and then inhibit the alkali-aggregate reaction effectively.