清水再生混凝土梁的裂缝和破坏形态分析

Analysis of cracks and failure modes of fair-faced recycled concrete beams

通过四点弯曲的加载方法,对6根不同再生粗骨料和粉煤灰取代率的清水再生混凝土梁进行了试验研究,分析了不同取代率对梁的裂缝和破坏形态的影响。结果表明,以再生粗骨料取代部分天然粗骨料,对梁的抗拉性能具有降低作用;而以粉煤灰取代部分水泥,对梁的抗拉性能具有提高作用;当再生骨料取代率为40%、粉煤灰取代率为30%时,清水混凝土梁相比普通混凝土梁,其极限承载力仅降低2.38%,为最佳取代率。

In this paper,the four-point bending loading method was used to test the fair-faced recycled concrete beams with different replacement rates of aggregates and the replacement rate of fly ash. The replacement ratio of recycled aggregates and the substitution rate of fly ash were analyzed. The influence of cracks and failure modes of fair-faced recycled concrete beams. The results show,recycled aggregates have a reduced effect on the tensile properties of fair-faced concrete beams,while fly ash has an improved effect on the tensile properties of fair-faced concrete beams. When the recycled aggregate replacement rate is 40%,the fly ash substitution rate is 30%. When the concrete beam is lower than the ordinary concrete beam,the ultimate bearing capacity is only 2.38%,which is the optimal replacement rate.