Qian Hui, Zhang Qingyuan, Zhang Xun, Deng Enfeng, Gao Jundong
School of Civil Engineering, Zhengzhou University, Zhengzhou 450001, China.
Materials (Basel). 2021 Dec 21;15(1):12. doi: 10.3390/ma15010012.
In order to realize the self-centering, high energy consumption, and high ductility of the existing building structure through strengthening and retrofit of structure, a method of reinforced concrete (RC) beam strengthened by using Shape Memory Alloy (SMA) and Engineered Cementitious Composites (ECC) was proposed. Four kinds of specimens were designed, including one beam strengthened with enlarging section area of steel reinforced concrete, one beam strengthened with enlarging section area of SMA reinforced concrete, beam strengthened with enlarging section area of SMA reinforced ECC, and beam strengthened with enlarging section area of steel reinforced ECC; these specimens were manufactured for the monotonic cycle loading tests study on its bending behavior. The influence on the bearing capacity, energy dissipation performance, and self-recovery capacity for each test specimens with different strengthening materials were investigated, especially the bending behavior of the beams strengthened by SMA reinforced ECC. The results show that, compared with the ordinary reinforced concrete beams, strengthening existing RC beam with enlarging section area of SMA reinforced ECC can improve the self-recovery capacity, ductility, and deformability of the specimens. Finally, a revised design formula for the bending capacity of RC beams, strengthened with enlarging sections of ECC, was proposed by considering the tensile capacity provided by ECC, and the calculated values are in good agreement with the experimental value, indicating that the revised formula can be well applied to the beam strengthening with enlarging section of SMA-ECC Materials.
为了通过结构加固和改造实现既有建筑结构的自复位、高耗能和高延性，提出了一种利用形状记忆合金（SMA）和工程水泥基复合材料（ECC）加固钢筋混凝土（RC）梁的方法。设计了四种试件，包括一根采用增大钢筋混凝土截面面积加固的梁、一根采用增大SMA钢筋混凝土截面面积加固的梁、一根采用增大SMA增强ECC截面面积加固的梁以及一根采用增大钢筋增强ECC截面面积加固的梁；制作这些试件用于对其弯曲性能进行单调循环加载试验研究。研究了不同加固材料对各试件承载力、耗能性能和自恢复能力的影响，尤其关注了SMA增强ECC加固梁的弯曲性能。结果表明，与普通钢筋混凝土梁相比，采用增大SMA增强ECC截面面积加固既有RC梁可提高试件的自恢复能力、延性和变形能力。最后，考虑ECC提供的抗拉能力，提出了ECC增大截面加固RC梁抗弯承载力的修正设计公式，计算值与试验值吻合良好，表明该修正公式可很好地应用于SMA - ECC材料增大截面梁加固。
