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针对普通再生混凝土性能普遍较差的问题,将再生混杂纤维与硅粉组成的纤维复合增强材料掺入再生混凝土,达到提高再生混凝土框架节点抗震承载能力的作用。通过3个纤维复合增强再生混凝土框架梁柱中节点试件的低周反复加载试验,对其破坏形态、承载机理及承载能力等进行了研究。结果表明:通过添加纤维复合增强材料,克服了再生混凝土节点受力和破坏多沿再生骨料新老砂浆界面呈酥松状破坏,即脆性破坏的弊端。在与普通再生混凝土节点配筋相同的条件下,纤维复合增强再生混凝土框架节点开裂较晚,节点裂缝开展延缓,有效抑制梁端纵筋黏结滑移,承载力提高,变形能力增强,纤维复合增强再生混凝土框架节点较普通再生混凝土框架节点的转角延性系数提高18.91%。节点区纵筋和箍筋应变分别达到2.0×10-3及2.5×10-3,表明添加纤维复合增强材料后混凝土与钢筋具有更好的协同工作性能。
Aiming at the poor performance of ordinary recycled concrete, the fiber reinforced composite material composed of recycled hybrid fibers and silica fume is incorporated into recycled concrete to improve the seismic load carrying capacity of recycled concrete frame joints. The low-cycle repeated loading test of the joint specimens in the beam-column of the reinforced concrete frame strengthened by three fiber composites was carried out and the failure mode, bearing mechanism and bearing capacity were studied. The results show that the shortcomings of brittle failure, ie, brittle failure, along the interface between the new and old mortar of recycled aggregate are overcooked by the addition of fiber composite reinforcements. Under the same conditions as ordinary recycled concrete joints, the joints of FRP reinforced concrete frame are delayed in cracking and the cracks in joints are delayed. The bond-slip of longitudinal reinforcement in the beam ends is restrained, the bearing capacity is increased, the deformation capacity is enhanced, and the fiber reinforced composite reinforced recycled concrete The corner ductility coefficient of frame joints is 18.91% higher than ordinary recycled concrete frame joints. The longitudinal strain and stirrup strain in the joint region reach 2.0 × 10-3 and 2.5 × 10-3, respectively, which shows that the concrete and reinforcing bar have better synergistic working performance after adding fiber composite reinforcements.