| 陈宇良,晏方,张绍松,叶培欢*,徐鸿飞.再生混凝土直剪力学性能试验及其本构关系[J].实验力学,2022,37(3):341~350 |
| 再生混凝土直剪力学性能试验及其本构关系 |
| Direct shear mechanical properties test and constitutive relations of recycled aggregate concrete |
| 投稿时间：2021-08-19 修订日期：2021-10-07 |
| DOI：10.7520/1001-4888-21-188 |
| 中文关键词: 直剪 再生混凝土 破坏机理 剪切强度 本构方程 |
| 英文关键词:direct shear recycled aggregate concrete failure mechanism shear strength constitutive equation |
| 基金项目:国家自然科学基金(51908141)；广西科技基地和人才专项(AD19110068)；广西工程材料与结构重点实验室(GXHRI-WEMS-2020-05)；广西高校中青年教师科研基础能力提升项目(2019KY0361) |
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| 中文摘要: |
| 为研究再生混凝土的直剪力学性能，以再生粗骨料取代率为变化参数，设计了66个试件进行直剪试验。本文通过试验观察了试件破坏形态，获取了再生混凝土全过程荷载-位移曲线及力学性能指标，分析了取代率对再生混凝土力学性能的影响。结果表明：直剪作用下再生混凝土发生典型的脆性破坏，剪切斜裂缝小于10°，断面酥碎；与普通混凝土相比，再生混凝土峰值剪力略微降低，幅度小于6.3%；随着取代率增大，再生混凝土峰值剪力变化不大，峰值位移、残余强度升高。再生混凝土直剪强度由黏结强度、咬合强度、摩阻强度构成，三者在总体中占比均为1/3。文中提出了再生混凝土直剪强度计算公式，并拟合得到了再生混凝土分段式剪切本构方程，拟合结果与实测结果吻合良好。 |
| 英文摘要: |
| In order to study the effect of recycle coarse aggregate replacement ratio on the mechanical properties of recycled aggregate concrete (RAC), 66 standard cubes were designed to test direct shear strength. The failure mode of the specimen was observed, the load-displacement curve and mechanical index of the specimens were obtained, and the failure mechanism and the effect of replacement ratio on mechanical performances of specimens were disclosed. The results show that the typical brittle failure of recycled concrete occurs under direct shear, shear cracks <10° and the section is brittle. Compared with natural concrete, the peak shear force of RAC is slightly reduced, within 6.3%. With the replacement ratio increases, the peak shear force of RAC change slightly, and the peak displacement and residual strength increase. The shear strength of RAC is comprised of cohesion strength, aggregate interlock strength and interface friction strength. In overall shear strength composition, the ratio of cohesion strength, aggregate interlock strength and interface friction strength are equal and was 1/3. The formula for calculating the direct shear strength of RAC was proposed. The segmented shear constitutive equation of recycled concrete was established and the fitting results are consistent with the measured results. |
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