Experimental Study On Compressive And Seismic Performance Of Concrete Small-sized Hollow Block Masonry Reinforced With HPFL

The concrete small hollow block is a competitive and prospects of the development of new wall materials for the advantage of saving soil and section, and it is widely applied in our country since the1960s. However,the concrete hollow brick walls have larger brittleness and poor seismic performance .In recent years the several earthquakes especially the 7.1 magnitude quake that happened in Yushu in 2010,plenty of concrete hollow brick structures were damaged in the earthquake.It is investigated that many houses in Yushu were built with poor- quality hollow blocks and construction, and mainly they had no good anti-seismic measures and lacked the bearing capacity. Therefore,to find a economic and effective strengthening method for concrete small hollow blocks have important practical value.High Performance Ferrocement Laminate (HPFL) is a new type of inorganic material, which is gradually the favour of reinforcement industry and used widely because of its remarkable reinforcement effect,durability,ageing resistance,fire resistance performance,convenient construction and environmental protection.Our task group have done some research on concrete structure reinforced with HPFL,from which we drew a conclusion that the ultimate bearing capacity, stiffness,crack-resistance and ductility could be significantly promoted when reinforced with HPFL,and it would be more economical than other strengthening methods like using carbon fiber and steel plate.This paper firstly makes comparative analysis on the failure pattern, stress-strain curve and the ultimate compressive capacity of the reinforced specimens and the ordinary ones on the basis of 18 standard test pieces .The experiments showed that this method is very effective,with the number of the reinforced walls’cracks increasing and ultimate compressive strain improved. Based on the experiment and theory of masonry’s compressive strength, the formulas of the reinforced concrete small hollow concrete-block masonry compressive strength is presented.Then, the comparative analysis of failure modes, shear capacity, hysteresis curve, skeleton curve, stiffness and stiffness degradation curve, ductility are made by carrying out the low cyclic loading test on one ordinary concrete small hollow block wall and five walls strengthened with HPFL.The test results showed that the ultimate bearing capacity and ductility of the reinforced walls were improved.In particular, the cracking load of walls reinforced with HPFL by the means of ring beam-structural column were greatly improved with full development of cracks and full hysteresis curve, greatly improving the capability of energy consumption.In addition, considering the test results, the existing research and analysis, the shear capacity calculation formulas of concrete small-sized hollow block masonry reinforced with HPFL were put forward . The formulas coincided well with the experimental results, available for practical design reference.