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纤维增强复合材料(FRP)在配筋砌体和混凝土结构加固领域,已经得到广泛应用。但对用FRP加固的砌体(或构件)的力学性能,特别是在恶劣环境下工作的构件性能,研究仍然不够充分。本文以采用在基材表面嵌入FRP方法(NSM-FRP),加固配筋混凝土砌块砌体试件,并对试件的力学性能进行研究;主要针对试件在经受不同环境荷载后的抗弯性能进行研究,分析了不同类型环境荷载对其力学性能的影响。本文所述试验,是将FRP加固后的混凝土砌块墙体试件,置于由电脑控制的环境模拟舱内,对其施加了350次不同环境荷载的循环,以模拟现实的自然环境条件。该环境条件模拟了美国中部地区20年的典型气候条件。共砌筑了7片配筋混凝土砌块砌体墙片试件,其中一片的原材料、几何参数与其它试件完全相同,但未进行加固处理的墙片试件作为参照组试件。上述墙片试件内布有低碳钢、配筋率(ρ)相同。本文将研究对象分为两组,每组有三个试件,采用NSM技术,分别使用碳纤维筋(CFRP)、玻璃纤维增强材料(GFRP)筋和碳纤维织物片(CFRP)对三个试件进行加固处理。第一组试件经过至少28天的实验室养护后进行力学试验,另一组则进行为期72天模拟自然环境条件的养护后,再进行试验。墙片试件成型养护后,需要承受加载速率为1.27mm/min的四点循环加载,以测试其抗弯承载力。试验结果可知,对比用CFRP筋和GFRP筋加固的墙片试件,用CFRP筋加固墙片受养护条件影响更大。加固后的配筋混凝土砌块砌体墙片的破坏形态包括两种,分别是混凝土砌块受剪破坏和FRP加固材料从砌体表面的剥离破坏。
Fiber reinforced composites (FRP) have been widely used in the field of reinforced masonry and concrete structures. However, the research on the mechanical properties of FRP reinforced masonry (or component), especially the performance of components working in harsh environment, is still not enough. In this paper, reinforced concrete block masonry specimens are reinforced by embedding FRP method (NSM-FRP) on the substrate surface, and the mechanical properties of the specimens are studied. Performance of the study, analysis of the different types of environmental load on the mechanical properties. The test described in this article is to put FRP reinforced concrete block wall specimens in a computer-controlled environment simulation chamber and apply 350 cycles of different environmental loads to simulate the actual natural environment conditions. This environmental condition simulates 20 years of typical climatic conditions in the central United States. A total of seven masonry reinforced concrete block masonry wall specimens, one of the raw materials, geometric parameters and other specimens exactly the same, but did not reinforce the wall specimens as a reference group specimens. The wall pieces of test pieces are made of mild steel with the same reinforcement ratio (ρ). In this paper, the subjects were divided into two groups, each with three specimens. NSM technology was used to reinforce the three specimens with carbon fiber reinforced plastic (CFRP), glass fiber reinforced plastic (GFRP) and carbon fiber woven fabric deal with. The first group of specimens was subjected to mechanical tests after at least 28 days of laboratory maintenance while the other group was subjected to 72 days of simulated natural environmental conditions before being tested. After molding and curing of the wall specimens, the four-point cycle loading with a loading rate of 1.27 mm / min is required to test the flexural capacity. Test results show that, compared with CFRP tendons and GFRP tendons reinforcement wall specimens, reinforced with CFRP tendons affected by conservation conditions more. Reinforced reinforced concrete block masonry wall failure forms include two kinds, namely, shear damage to concrete blocks and FRP reinforcement material from the masonry surface peel damage.