【2018-0307】自密实轻集料混凝土双轴受力力学性能

《复合材料学报》优先在线发表论文。

摘  要：为探究自密实轻集料混凝土双轴力学性能，采用三轴试验机对其进行双轴压-压和双轴拉-压试验，得到不同工况下的应力-应变曲线及其破坏形态，通过提取应力-应变曲线峰值应力和峰值应变，并与相关文献普通混凝土与轻集料混凝土研究成果对比，分析自密实轻集料混凝土双轴力学性能。研究结果表明：双轴压-压工况下，当侧向压应力较低时，试件主要呈现剪切破坏形态；当侧向应力较高时，试件呈劈裂破坏形态。双轴拉-压工况下，试件主要呈劈拉破坏形态，与侧向应力无关。随着侧向压应力的提高，自密实轻集料混凝土主压应力相对比无侧向应力工况具有明显提高，峰值应力最大提高均值幅度为68.08%，主拉应力随侧向压应力的提高逐步降低，最大降低幅度为62.35%。应用Kupfer双轴受力破坏准则验证自密实轻集料混凝土受侧向应力影响变化规律较为保守，同时基于Kupfer提出自密实轻集料混凝土双轴力学性能破坏准则，所得到的破坏准则方程具有良好的适用性。

关键词：自密实轻集料混凝土；双轴压-压；双轴拉-压；试验研究；破坏准则

Abstract: In order to explore the mechanical properties of self-compacting lightweight aggregate concrete under biaxial loading, the three axis test machine was used to carry out biaxial compression-compression and biaxial tension -compression. The stress-strain curve and its failure form under different working conditions were obtained. The peak stress and peak strain of the stress-strain curve were extracted, and the ordinary concrete and the lightweight aggregate concrete in the related literature were obtained. The biaxial mechanical properties of self-compacting lightweight aggregate concrete was compared with research results of ordinary concrete and the lightweight aggregate concrete. The results show that when the lateral pressure is low, the specimen mainly presents the shear failure mode and when the lateral stress is high, the specimen is split. Under the condition of biaxial tension-compression, the specimen is mainly splitting failure, which is independent of lateral stress. With the increase of lateral pressure stress, the main compressive stress of the self-compacting lightweight aggregate concrete is obviously higher than that without lateral stress, the maximum increaseing of peak stress is 68.08%, and the main tensile stress gradually decreases with the increase of lateral pressure stress, and the maximum decrease is 62.35%. Using the Kupfer biaxial stress failure criterion, it is proved that the influence of the lateral stress on the self- compacting lightweight aggregate concrete is more conservative. At the same time, the failure criterion of the self- compacting lightweight aggregate concrete biaxial mechanical properties is proposed based on Kupfer. The failure criterion equation has good applicability.

Keywords: self-compacting lightweight aggregate concrete; biaxial compression-compression; biaxial tension-compression; experimental research; failure criterion

作者：孙雪等，金陵科技学院 建筑工程学院，南京

通讯作者：余振鹏，东南大学 交通学院，南京

全文详见中国知网学术期刊优先数字出版。