干湿循环下复合固废填料配比对强度的影响

Abstract

Nine series of samples of composite lightweight geomaterials were produced by mixing waste foundry sand, fly ash, expanded polystyrene (EPS) bead, water and Portland cement in proportions, which were exposed to designated drying-wetting (D-W) cycles. Uniaxial compression tests were carried out on the samples to investigate the effect of mix proportions onto the structural integrity of the geomaterial. Results indicate that the geomaterial offers promise as soil-cement mixtures after up to 8 D-W cycles. Along with increase of cement content, the compressive strength of the geomaterial gains in initial 2-3 D-W actions. To add fly ash properly enhances the strength gain and D-W resistance of the geomaterial. Although EPS addition prompts the light weight of the geomaterial, its addition, if above 1% (by mass), will lead to strength loss. Optimal mix proportions for the geomaterial are suggested. = 通过对不同配比的9组复合固废轻质填料(简称轻质填料)试样在不同干湿循环次数下的单轴抗压强度试验,分析了干湿循环下各组分掺入比对轻质填料抗压强度的影响.结果表明:轻质填料经历8次干湿循环后仍有较好的力学性能,达到或超过水泥土的强度要求.随着水泥掺量的增加,轻质填料在早期干湿循环过程中强度提高,有助于后期抗干湿循环.适量掺入粉煤灰,有利于提高轻质填料的强度及抗干湿循环能力.聚苯乙烯颗粒超过1％(质量分数),会衰减轻质填料的强度和降低其抗干湿破坏的能力.提出了轻质填料的配比范围.