碳纤维再生混凝土复合受剪力学性能试验

Composite shear mechanical properties of carbon fiber recycled aggregate concrete

  • 摘要: 为研究碳纤维再生混凝土复合受剪状态下的力学性能,以碳纤维掺量、压应力比、再生粗骨料取代率为试验参数,完成了102个立方体试件的复合受剪试验。试验观察了碳纤维再生混凝土试件的破坏形态,获取了剪切状态下荷载-位移曲线,分析了3种试验参数对试件剪切强度、峰值位移及损伤演化规律的影响。研究表明:压应力比对碳纤维再生混凝土试件的破坏形态有显著影响,随着压应力比的增大,试件的裂缝数量和角度增大;0.3vol%掺量的碳纤维可提高试件剪切强度12%左右,压应力比由0增至0.09和0.18后,试件剪切强度时分别是其的2.34倍、3.25倍,再生粗骨料取代率对峰值剪切强度影响较小;增大压应力比可有效减缓损伤的发展;采用的损伤本构能较好的反映复合受剪的剪力-位移关系。

     

    Abstract: To study the mechanical properties of carbon fiber recycled aggregate concrete under composite shear condition, the composite shear test of 102 cube specimens was completed with recycled coarse aggregate replacement rate, compressive stress ratio and carbon fiber content as test parameters. The failure mode of carbon fiber reinforced recycled concrete specimens was observed, and the load-displacement curve under shear state was obtained. The effects of three kinds of change parameters on the shear strength, peak displacement, and damage evolution law of specimens were analyzed. The research shows that the compressive stress ratio has a significant indigenous effect on the failure mode of the carbon fiber reinforced recycled concrete specimen, and the number and angle of cracks increase with the increase of the compressive stress ratio. 0.3vol% content of carbon fiber can improve the shear strength of the specimen by about 12%. When the compressive stress ratio increases from 0 to 0.09 and 0.18, the shear strength of the specimen is 2.34 and 3.25 times that of the specimen, respectively. The recycled coarse aggregate replacement rate has little effect on the peak shear strength. Increasing the compression stress ratio can effectively slow down the development of damage, and the adopted damage constitutive can better reflect the shear-displacement relationship of composite shear.

     

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