BFRP筋与玄武岩纤维再生混凝土粘结性能

BOND BEHAVIOR BETWEEN BFRP BARS AND BASALT FIBER REINFORCED RECYCLED AGGREGATE CONCRETE

为了研究玄武岩纤维再生混凝土与BFRP筋的粘结性能,通过42个试件的中心拉拔试验,研究再生粗骨料取代率、BFRP筋的直径以及筋材的表面特征对其的影响。试验结果表明:随着再生骨料取代率的增加,峰值极限粘结应力逐渐降低,峰值滑移量呈现先减小后增大的趋势;随着BFRP筋直径的增大,粘结应力逐渐增大,与峰值粘结应力对应的峰值滑移量逐渐增大,但整体的变化范围很小;筋材的表面状况对玄武岩纤维再生混凝土与BFRP筋的粘结性能影响很大。分别采用改进BPE模型、CMR模型及连续曲线模型的计算值与实验值比较分析其极限粘结应力,依据试验结果采用非线性回归分析得出粘结-滑移本构关系模型,该模型的计算值与实验值吻合较好。

To study the bond properties between BFRP bars and basalt fiber recycled concrete, the center pullout test with 42 specimens was performed. The influence of the replacement ratio of recycled coarse aggregate, the diameter and the surface characteristics of the BFRP bars were studied. The results indicate that with the increase of the replacement ratio of recycled aggregate, the bond stress of peak value decreases gradually, and the peak slip de- creases firstly and then increases. With the increase of the diameter of BFRP, the bond stress increases gradually, and the peak value of bond stress is gradually increased, the peak slip value corresponding to the peak bond stress is gradually increased. But the overall change range is very small. The surface condition of the BFRP bar has greatly influence on the bond behavior of the basalt fiber recycled concrete and the BFRP bar. Using the improved BPE model, CMR model, and the continuous curve model of the calculated value and the experimental value of the com- parative analysis of the ultimate bond stress, the bond-slip constitutive relation model is obtained by nonlinear re- gression analysis, and the calculated values of the model are in good agreement with the experimental results.