混凝土多孔砖砌体水平灰缝钢筋锚固试验

摘要

目的 研究钢筋在砂浆中的粘结锚固机理及钢筋内力沿锚固长度的变化,确定钢筋在混凝土多孔砖水平灰缝中的锚固长度.方法 通过对17个试件51根钢筋的拉拔试验,采用改变其中一个参数而固定其余参数的方法,研究分析钢筋直径、竖向正应力、砂浆强度、钢筋埋置长度等因素对试验结果的影响.结果 随着正应力的增加界限锚固长度逐渐变短,当正应力为零时界限锚固长度最长,其值为390 mm,由此可建议在实际工程中钢筋在砂浆的锚固长度可取400mm.结论 混凝土多孔砖砌体水平灰缝钢筋的粘结强度比实心黏土砖的有较大下降,验证了现行规范中关于砌体钢筋锚固长度已不适合于混凝土多孔砖砌体.%This paper presents a research on the bond anchorage mechanism of reinforced bar in mortar and the changes of the internal force of reinforced bar along the anchor length,in order to determine the anchor length of reinforced bar in the horizontal mortar joint of concrete porous bricks. By using the pull-out tests on 17 specimens and 51 reinforced bars and by changing one of the parameters while fixing the rest,this paper alms to analyze the impact of factors such as the diameter of reinforced bar, vertical normal stress, the intensity of mortar, the buried length of reinforced bar on the results of the tests. With the increase of normal stress, the length of boundary anchor becomes shorter gradually. When normal stress is 0, the length of the boundary anchor becomes longest, and its value is 390mm. Therefore, we suggest that the length of the reinforced bar in anchor in an actual project should be 40O mm. The bonding strength of the reinforced bar in the horizontal mortar joint of concrete porous bricks drops greater than that of solid clay brick, which verifies that the length of masonry reinforced anchor is not suitable for concrete porous brick masonry structure in current regulations.