玻纤格栅配筋砌体受力性能及基于性能抗震设计方法研究

There are several defects of the reinforced masonry structures, such as the reduction of the strength, thermal bridge effect that is not conducive to energy-saving insulation causing by thicker mortar joint, and the corrosion of rebars. To resolve those defects, our team is proposed to replace the horizontal rebars in reinforced masonry structures by glass fiber grid which is one of common seen geotextile material in asphalt pavement. Through this replacement, it could not only improve the seismic performance corrosion resistance, but also increase the compressive strength and energy-saving insulation by reducing the thickness of mortar joint. Systematic test and theoretical study have been conducted, including the bond anchorage mechanism between glass fiber grid and special mortar, the axial compressive property, the bending tensile performance, the seismic performance under low reversed cyclic loading. The theoretical model of shear and compressive strength based on the theory of reinforced concrete softened truss theory has been defined. Shear bearing capacity formula is obtained to understand the influence of various factors that promote the theoretical research. Three levels fortification of displacement performance index has been given by Performance-based seismic design theory. A simplified method for determining the target structure displacement has been obtained on the basis of improved capacity spectrum method by Chopra. It promotes the study of masonry structure seismic design theory. The new kind of masonry structure system—glass fiber grid reinforced masonry conducted by our team. It has a broad prospect in application. It has good application prospect and important theoretical value and practical significance in the masonry structure seismic and promoting the development of building energy efficiency.

针对配筋砌体存在配筋层砂浆灰缝较厚，降低了强度及热桥效应不利于节能保温，而且钢筋易被锈蚀等缺点。项目组拟采用在沥青路面中铺设的玻纤格栅土工材料替代配筋砌体中的水平钢筋，其具有提高抗震性能、有效减小灰缝厚度、方便施工及耐腐蚀等优点。本项目对玻纤格栅与专用砂浆的粘结锚固机理、玻纤格栅配筋砌体的轴心受压性能、弯曲受拉性能和低周反复荷载作用下的抗震性能进行了系统的试验和理论研究；建立基于钢筋混凝土软化桁架理论的剪压强度理论模型，给出受剪承载力计算公式，深入理解各因素的影响，促进理论研究；并基于性能抗震设计理论，给出对应我国抗震规范三水准设防的位移性能指标，在Chopra改进的能力谱方法基础上，提出结构目标位移的简化确定方法，促进了砌体结构抗震设计理论研究。本项目提出了一种新型的砌体结构形式—玻纤格栅配筋砌体，具有很好的应用前景，对砌体结构抗震及促进建筑节能的发展具有重要的理论价值和现实意义。

针对配筋砌体存在配筋层砂浆灰缝较厚，降低了强度及热桥效应不利于节能保温，而且钢筋易被锈蚀等缺点。项目采用在沥青路面中铺设的玻纤格栅土工材料替代配筋砌体中的水平钢筋，其具有提高抗震性能、有效减小灰缝厚度、方便施工等优点。项目对(1) 玻纤格栅材料力学性能；(2) 玻纤格栅配筋砌体基本受力(抗压、弯曲受拉及抗剪)性能试验；(3) 低周反复荷载作用下玻纤格栅配筋砌体墙片的抗震性能试验；(4) 玻纤格栅配筋砌块墙体抗震性能有限元分析及抗震设计计算四个方面进行了系统的试验和理论研究。通过以上研究内容项目得出如下结果：(1)明确了玻纤格栅材料力学性能、玻纤格栅配筋砌体的轴心受压性能、弯曲受拉性能及抗剪性能。提出玻纤格栅配筋砌体的抗压、抗弯及抗剪承载力计算公式及本构关系模型；(2)得到玻纤格栅配筋砌体墙体的低周反复荷载作用下的破坏现象、荷载特征值及位移特征值，对比分析不同参数设计墙体的滞回曲线、骨架曲线、刚度退化曲线、能耗系数及延性系数等。根据试验同时得出：玻纤格栅墙与素墙相比开裂荷载提高了26%，极限荷载提高了20%，配纤维格栅能够提高墙体抗剪承载力，同时能延缓墙体开裂；随着玻纤格栅配纤率提高开裂荷载变化不大，极限荷载及延性提高较为明显；但配格栅墙体承载力及延性值略低于配钢筋墙体，建议提高配纤维率；(3)建立玻纤格栅配筋砌块墙体的恢复力模型。深入理解各因素对抗剪承载力的影响，根据拉摩理论建立的玻纤格栅配筋砌体抗震抗剪承载力计算公式。给出层间位移角计算值及目标位移的确定方法，促进了砌体结构抗震设计理论研究。项目提出的新型砌体结构形式—玻纤格栅配筋砌体是可行的，玻纤格栅可以作为钢筋的理想替代品用于砌体水平灰缝中，具有很好的应用前景，对砌体结构抗震及促进建筑节能的发展具有重要的理论价值和现实意义。