新型装配式建筑免拆模壳板抗裂性能试验研究

Experimental Study on Crack Resistance of New Prefabricated Building Shell Plates without Removing Molds

模块化集成建筑(MiC)由预制混凝土模块通过后浇混凝土连接组成。为了实现模块之间剪力墙的免支模浇筑,同时减少材料用量,设置了厚度仅3 cm的预制免拆模壳板,但其板型较薄,在混凝土浇筑过程中其受力性能和破坏机理尚不明确。故针对免拆模壳板的力学性能进行了试验并建立了有限元模型,同时设计了一种新型加载钢架,对3组预制钢筋混凝土免拆模壳板(不开洞、侧边开洞、中间开洞)进行静力梯形堆载试验,得出其开裂荷载、挠度曲线以及荷载-应变曲线等。结果表明:三组试件均在桁架钢筋处发生混凝土开裂且承载力始终保持增长趋势,说明模壳板承载能力良好;由三组试件裂缝发展情况可以看出,裂缝出现的位置和试件破坏的趋势基本相同。

Modular integrated Construction(MiC)consist of precast concrete modules connected by post-casted concrete.To realize the mold-free casting of shear walls between modules as well as material reduction,a prefabricated mold-free shell plate with a thickness of on⁃ly 3 cm was set up.Considering its thickness,the mechanical behaviors and failure mechanism of concrete in the process of concrete pouring were still to be clear.Therefore,the mechanical properties of the mold-free shell plate were experimentally studied and a finite element model was established.A new type of loading steel frame was designed.The static trapezoidal loading test was carried out on three grarps of prefabricated reinforced concrete mold shell plates(one without opening holes,one with opening holes on the side and one with opening holes in the middle).The cracking load,deflection curve and load-strain curve are obtained.The analysis and test re⁃sults show that the concrete cracking occurs in the truss reinforcement of the three groups of specimens and the bearing capacity keeps increasing all the time,indicating that the bearing capacity of the mold shell is good.The crack development of the three groups of spec⁃imens showed that the crack location and the failure trend of the specimen were basically the same.