竹-PVA纤维再生混凝土组合结构大棚棚架的性能研究

Study on Performance of Bamboo-PVA Fiber Recycled Concrete Composite Structure Greenhouse

竹-PVA纤维混凝土组合结构拱架由T型竹胶板拱架和PVA混凝土边桁架构成。参考相关文献推荐的跨高比结合结构力学求解器试算结果确定最优拱架跨度和高度及截面尺寸,并通过反复试验确定最终边桁架混凝土配合比。为确定棚架结构的实际承载特性,对普通单栋大棚拱架进行分级加载试验,测定加载过程的应变及位移变化量。整个加载过程中组合拱架在弹性状态下工作,竖向及水平位移均不超过10 mm,最大压应变为254×10^-6出现在拱架施加水平荷载侧的肩部腹板处,取抗压弹性模量为6760 MPa,按计算可得最大压应力为2 MPa,不大于容许应力50 MPa,试验结果表明组合拱架结构可满足一般大棚的荷重使用要求。

Bamboo-PVA fiber reinforced concrete composite structure arch was set up with T-shaped bamboo plywood arch and PVA concrete side truss.The optimal arch span,height and section size were determined by referring to the recommended span height ratio and the trial results of structural mechanics solver,and the final concrete mix ratio of side truss was determined by repeated tests.In order to determine the actual load-bearing characteristics of the shed structure,the ordinary single shed arch frame was tested by the step loading test to determine the strain and displacement change during the loading process.During the whole loading process,the composite arch worked in the elastic state,and the vertical and horizontal displacement were not more than 10 mm,the test maximum compressive strain was 254×10^-6,which appeared at the shoulder web of the side where the horizontal load was applied to the arch.The compressive modulus of elasticity was 6760 MPa,and the calculated maximum compressive stress was 2 MPa,which was not greater than the allowable stress 50 MPa.The test results show that the composite arch structure can meet the load requirements of the general shed.