配筋石膏梁受力性能试验研究

Experimental Research on Mechanical Properties of Reinforced Gypsum Beams

为研究配筋石膏梁的受力性能及配筋率和配筋形式的影响规律,对7根单筋石膏梁和5根双筋石膏梁进行了静力加载试验。试验结果表明:单筋试件B1~B5和双筋试件B8、B9均发生正截面受弯适筋破坏,单筋试件B6、B7发生超筋破坏;由于石膏实际强度较低导致截面受剪承载力偏低,试件B5、B6和B10发生受弯破坏的同时也发生了受剪破坏,B11、B12则发生受剪斜压破坏;发生正截面受弯适筋破坏的单筋试件,随着受拉钢筋配筋率的增加,试件的峰值承载力有所提高,位移延性系数逐渐减小;受拉纵筋相同时,配置受压纵筋可有效提高试件位移延性;配筋石膏梁基本符合平截面假定;各试件正常使用荷载下最大裂缝宽度和挠度均小于规范GB 50010—2010中规定的限值,配筋石膏梁可以满足正常使用极限状态要求。

To investigate the mechanical properties of reinforced gypsum beams and analyze the effects of reinforcement ratio and pattern,static loading tests were conducted on seven single-reinforced gypsum beams and five double-reinforced gypsum beams.The test results indicated that both the single-reinforced specimens B1-B5 and the double-reinforced specimens B8 and B9 exhibited bending failure at normal sections as proper reinforced concrete beams,while the single-reinforced specimens B6 and B7 demonstrated bending failure as over-reinforced concrete beams.Due to the low actual strength of gypsum,the shear bearing capacity of the section was relatively low.As a result,specimens B5,B6,and B10 experienced both bending failure and shear failure,and B11 and B12 underwent shear oblique compression failure.The peak bearing capacity of the proper reinforced specimens increased with the increase of the tensile reinforcement ratio,while the displacement ductility coefficient gradually decreased.When the tensile longitudinal reinforcement remained constant,the addition of compressive longitudinal reinforcement could effectively enhance the displacement ductility of the specimens.The reinforced gypsum beam basically conformed to the assumption of a plane section.The maximum crack width and deflection observed in each specimen under service load remained below the specified limit values,indicating that the reinforced gypsum beams satisfactorily met the requirements of the serviceability limit state in Design of Concrete Structures(GB 50010—2010).