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预制空心楼盖板HPFL整体化后平面外强度研究
The Out-of-Plane Strength of The Precast Hollow Floor Plate after Integrity Reinforcement by HPFL
【作者】 杨芳；
【作者基本信息】 湖南大学 ， 建筑与土木工程（专业学位）， 2015， 硕士
【摘要】 本文对高性能水泥复合砂浆钢筋网(以下简称HPFL)薄层作为预制空心楼板的叠合层,对整体化后的预制空心楼盖板平面外强度进行试验研究。预制空心楼盖板HPFL整体化是结合预制圆孔空心板和HPFL薄层两者的优点,通过在板上铺设不同宽度的HPFL窄条带,使HPFL叠合层和空心板形成一个整体,增强楼板的整体性,进而增强板的平面外强度、克服预制空心楼盖板整体性差的问题,使HPFL预制空心楼盖板成为装配整体式楼盖体系。试验通过各拼装预制空心板下降的挠度值、叠合层裂缝开展情况,以及试件在各工况下任一预制空心板是否发生坍塌、坠落,进而研究预制空心楼盖板HPFL整体化后平面外强度。本试验主要对HPFL作为预制空心楼盖板的叠合层,在考虑两倍动力系数的情况下,通过三种工况对整体化后楼板的平面外强度进行研究。工况一为使用黄土分四级进行加载,加载结束后进行工况二;工况二为掏空试件A轴边板下的墙体,工况三在工况二的基础上掏空试件B轴中间两块板下的墙体,A、B轴见图2.6。通过板下墙体的撤出,模拟地震作用下板下任意位置墙体的破坏,研究HPFL作为预制空心楼盖板的叠合层对整体化的拼装楼盖板平面外强度的影响。本文通过ABAQUS有限元分析程序进行模拟四块板和六块板拼装的预制空心楼盖板模型,通过有限元模型计算出来的四块板整体化后强度值与实际试验结果符合较好。有限元还通过楼板悬挑1500mm来模拟墙体大面积倒塌的拼装楼板,模拟结果显示:板与叠合层未发生剥离,且无任何空心板发生坍塌、坠落。试验结果表明,预制空心板在板下不同位置的支撑墙体破坏后,整体化后的空心楼盖板件按空心板横向悬挑板受力,板端部产生向下挠曲,空心板横向悬挑长度为2块板宽(1000mm),叠合层与任意一块空心板之间均未出现剥离现象;没有HPFL作为叠合层的空心楼板发生脆性破坏,悬挑处空心板直接坍塌坠落。该试验证明HPFL整体化后的预制空心楼盖板,能有效地提高预制空心楼盖板的整体性,板的平面外强度增加,空心楼板在水平面的两个垂直方向上连续;整体化后的预制空心楼盖板成为水平面内任意向刚度接近无穷大的横向构件,拼装的预制空心楼盖板的整体性及抗震性能得到保证。本中提出的预制空心板HPFL整体化的方法不仅可供工程设计参考,也可为广大村镇地区在新建房屋中,使用价廉物美的预制空心板作为楼盖板提供整体化施工指导,同时对已有工程选用HPFL窄条带加固预制空心板构件提出一些建议。
【Abstract】 In this paper, the out-of-plane strength of the precast hollow hloor plate was investigated after integrity reinforcement by HPFL composite covers. HPFL is an abbreviation of the high performance Ferro-cement laminates. HPFL precast hollow floor slab is a perfect combination of both precast hollow circular hole and HPFL, by paving different widths HPFL of narrow strip on the surface of precast hollow slabs, so as to make HPFL composite covers and precast hollow slabs form a whole, enhancing the integrity of the floor and overcoming the fatal pro blem of precast hollow floors.This interity way could make HPFL precast hollow floor slab becoming monolithic assembly slab systems. We had research ed on the out-of-plane strength of the slabs reinforcement by measuring the deflection of each assembly prec ast hollow, crack development,and whether either precast hollow slabs collapsed in all cases.In the experience, the out-of-plane strength of the precast hollow hloor plate was investigated after integrity reinforcement by HPFL composite covers by three conditions under simulate earthquakes action. First case was used sands to add live load by four levels in consideration of twice times dynamic coefficient, after the loading ended, second case was emptied the wall under the first hollow slab at the side slabs of A-axis of wall, third case was emptied the wall of B-axis under the hollow slabs. Second case and third case were aimed to simulated wall collapsed at uncertain positions in earthquake. We also used Abaqus finite element analysis program to simulate and analyze the test model. The calculated deflections of hollow slabs in finite element model were match with the actual test results well.As the composite cover of precast hollow plate, HPFL can effectively improve the integrity of precast hollow floor slab, also increase the the out-of-plane strength of slab, made hollow slab continuous at both vertical directions of horizontal direction, and any stiffness of the horizontal components in this plane approaches infinity, so structural integrity and earthquake resistant performance o f hollow slabs are guaranteed. HPFL integrity reinforcement for precast hollow plate not only can be a reference in engineering design, but also in the majority of towns and villages areas using quality and inexpensive precast concrete hollow slab s in new buildings.