钢纤维粉煤灰再生混凝土强度正交试验研究

发布时间：2018-01-13 10:03

本文关键词：钢纤维粉煤灰再生混凝土强度正交试验研究　出处：《建筑材料学报》2014年04期 　论文类型：期刊论文

【摘要】：利用正交试验方法对钢纤维粉煤灰再生混凝土(以下简称再生混凝土)的强度性能进行了试验,考察了粉煤灰取代率(质量分数)、钢纤维掺量(体积分数)和再生粗骨料取代率(质量分数)对再生混凝土28d立方体抗压强度、劈裂抗拉强度和抗折强度的影响,并对试验结果进行了系统分析.结果表明:粉煤灰取代率对再生混凝土抗压与抗折强度的影响规律一致,但对其劈裂抗拉强度的影响规律却不相同;再生混凝土抗压强度、劈裂抗拉强度和抗折强度均随钢纤维掺量的增加而增大,但钢纤维掺量对劈裂抗拉和抗折强度的影响显著,对抗压强度的影响较小;再生粗骨料取代率对抗压强度、劈裂抗拉强度和抗折强度的影响规律基本一致,强度总体上随再生粗骨料取代率的增大而增大.要使再生混凝土强度得到提高,需降低粉煤灰的取代率,增大钢纤维掺量和再生粗骨料取代率.当粉煤灰取代率在30%以内、钢纤维掺量在1.8%以内时,粉煤灰取代率对再生混凝土抗压强度的影响最大,其次是再生粗骨料取代率,最次是钢纤维掺量;钢纤维掺量对再生混凝土劈裂抗拉强度和抗折强度的影响最大,其次是粉煤灰取代率,最次是再生粗骨料取代率.
[Abstract]:The strength performance of steel fiber fly ash recycled concrete (hereinafter referred to as recycled concrete) was tested by orthogonal test method, and the replacement ratio (mass fraction) of fly ash was investigated. The effects of steel fiber content (volume fraction) and the replacement ratio of recycled coarse aggregate (mass fraction) on the compressive strength, splitting tensile strength and flexural strength of recycled concrete for 28 days. The experimental results show that the influence of fly ash substitution ratio on compressive strength and flexural strength of recycled concrete is consistent, but the influence law on splitting tensile strength is different. The compressive strength, splitting tensile strength and flexural strength of recycled concrete increase with the increase of steel fiber content, but the effect of steel fiber content on splitting tensile strength and flexural strength is significant, and the effect on compressive strength is small. The influence of replacement ratio of recycled coarse aggregate on compressive strength, splitting tensile strength and flexural strength is basically the same, and the strength increases with the increase of recycled coarse aggregate substitution rate, and the strength of recycled concrete should be improved. It is necessary to reduce the substitution rate of fly ash and increase the substitution ratio of steel fiber and regenerated coarse aggregate. When the replacement ratio of fly ash is less than 30%, the content of steel fiber is less than 1.8%. The replacement ratio of fly ash has the greatest influence on the compressive strength of recycled concrete, followed by the replacement rate of recycled coarse aggregate and the content of steel fiber. The effect of steel fiber content on the splitting tensile strength and flexural strength of recycled concrete is the greatest, followed by the replacement rate of fly ash and the replacement rate of recycled coarse aggregate.
【作者单位】：湖南大学土木工程学院;湘潭大学土木工程与力学学院;惠州学院建筑与土木工程系;
【基金】：国家自然科学基金资助项目(51278182) 湖南省大学生研究性学习和创新性实验计划资助项目(湘教通[2013]191号)
【分类号】：TU528.0
【正文快照】： 再生骨料具有孔隙率和吸水率大、压碎指标值高以及强度低等特点,再生骨料的这些特点在一定程度上决定了配制出的再生混凝土的性能较普通混凝土有较大程度的劣化[1-4].为了弥补这些缺陷,一些研究者在再生混凝土中掺入钢纤维,利用钢纤维的增强增韧作用改善再生混凝土的力学性能.

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