钢筋混凝土梁水平钢筋抗剪机理试验研究-土木工程专业论文.docxVIP

摘要摘要 摘要 摘要 本文首先从斜截面破坏的机理出发，提出在梁高范围内配置水平抗剪钢筋的 观点，继而设计试验模型研究钢筋混凝土梁在配置水平抗剪钢筋后斜截面的受力 性能。 为了研究不同剪跨比情况下，配置水平钢筋后梁的斜截面应力应变发展情 况，设计了试验模型系列1一四根同时配置垂直箍筋和水平钢筋的矩形梁；为了 研究不同加载方式对截面受力性能的影响以及水平抗剪钢筋配置后对截面抗剪 承载力的影响，设计了试验模型系列2一六根相同截面尺寸、相同纵向配筋、相 同剪跨比、相同垂直箍筋配置但加载方式、水平配筋有所不同的矩形梁。 试验中．观察了从裂缝出现到模型破坏的全过程，记录了斜裂缝的发展状况、 箍筋及截面破坏时的荷载，并测量了水平抗剪钢筋和垂直箍筋在各个工作阶段的 应变。试验结果表明： ①钢筋混凝土梁在增加水平抗剪钢筋配置后，剪压区截面在各个工作阶段基 本保持平截面。 ②水平钢筋在荷载作用下均出现拉应变，说明其承担了主拉应力的水平分 量。 ③在反复荷载作用下，箍筋拉应变数值加大，说明骨料咬合力减小。 ④在有水平钢筋时，箍筋屈服荷载增大，说明在有水平钢筋时箍筋发挥更完 全，而不用分出一部分面积去承担一部分主拉应力的水平分量，从而其屈服荷载 提高。 关键词：钢筋混凝土梁，水平抗剪钢筋，平截面假定，骨料咬合力，抗剪极限承 载力 AbstractAbstract Abstract Abstract On the basis of shear mechanism in RC beam，the concept of horizontal shear resistance steel reinforcement was presented．Test beams were designed to study the shear resistance behavior ofreinforeed concrete rectangle beam with rectangle section and horizontal steel bars． n order to study the shear behavior with horizontal steel bar．4 reinforced concrete beams with different shear span ratio were tested．Each beam had the same cross·section and contained the same quantity of main longitudinal steel，stirrup，and horizontal steel reinforcement． Furthermore，in order to study the influence of different load mode and horizontal steel reinforcement to ultimate shear behavior,6 reinforced concrete beams with the same rectangle section，with without the same quantity of longitudinal and vertical steel reinforcement were tested． During the experiment，the whole process from the first crack to structure failure WaS observed．The diagonal crack development，stirrup yielding load，and failure load were recorded． The strain of horizontal steel bar and stirrup at different load stage were measured．The tests showed the following results： ①In the conventional reinforced concrete beam with appropriate longitudinal steel and stirrup reinforcement adding horizontal shear resistance steel bars，the sections within the shearspan remain basically plain at each load stage． @)Under the action of toad，the horiz