Experimental Study On The Behaviour Of Composite GFRP Concrete Block Wall

Fiber-reinforced polymers (FRP) provide a new alternative for strengthening of masonry structures. And with the advantages of convenient construction, reduced construction time, and economical construction cost .etc. this strengthening method is more and more popular. This paper presents an experimental investigation into the effectiveness of using glass-fiber reinforced polymers (GFRP) in existing concrete small hollow block walls strengthening to resist out-of-plane loads.Four unreinforced masonry walls (1790×790×190mm3) were constructed with concrete small hollow block and grouted with C20 and C40 concrete. In those four specimens, three were externally strengthened with glass fiber-reinforced polymers (GFRP) composite strips, and the contrast specimen wall-0 is an exception. Out-of-plane load was uniformly applied to the four specimens with an air bag. The main parameters measured in the experiment are the values of the distributed load, the tensile strains in composites, the compressive strains in the compression zone and the deflection at midspan .etc.Through the analysis of experimental results, detailed researches are done on the composite walls'out-of-plane flexural capacity, delamination of GFRP, load-deflection response and so on, with the critical coverage ratio defined, some equations to predict the out-of-plane flexural capacity of specimens on under-reinforced condition and over-reinforced condition given, and the shearing strength of masonry walls under out-of-plane loads discussed; And it is also concluded from the experiment that the load-deflection curves can be divided into two linear phases (before and after cracking), and the corresponding formula which can predict the deflections of specimens are given; Besides, Chen and Teng model is applied in order to study delamination of GFRP, and the delamination shapes predicted fit well with the experiment results.