Secondary Load-Experiment Of Full-scale RC Beam Reinforced By Polyvinyl Alcohol-Engineered Cementitious Composite Mortar In Flexure

Polyvinyl Alcohol-Engineered Cementitious Composite (PVA-ECC) technology is a new method to reinforce the concrete structure and masonry structure. Depending on the fine properties of the materials and the fine cohesion of the boundary agent, both the forrocement layer and the pre-component work harmoniously are as a whole. By means of test and theoretical research on the full-scale beams under secondary load, this thesis will make valuable contributions to the past achievements, and provide full and accurate experiments and theory to practice projects. As a part of series of studies on high toughness fiber mortar strengthened reinforced concrete beams, this thesis provides a good trial basis and theoretical analysis of the strengthen of PVA-ECC reinforced concrete beams.In this trial, loading test of eight full-scale beams has been done. The infection, come from different first-loading extent and different height of reinforcement at the side of RC beam, to ultimate bearing capacity of reinforced beams, steel strain and concrete strain has been studied. Basing on the trial and theoretical analysis, taking account of the inflection of steel mesh on the side face, simplified formula for calculating the ultimate bearing capacity of reinforced beams was proposed.Based on the crack and deflection datas of one control beams and six strengthened beams,the varieties of trendence of crack and stiffness under secondary load are analysised. Formulars are proposed for the interval and width of cracks and stiffness of section,and the test values and the formular values are compared.Analysis the yield and ultimate capacities in the form of analytic formular,including the affects of aspect steels. Nonlinear finite element methods is employed to simulate the process of the loading test, in order to testify the affectivity of strengthening method,and the test values are compared with the results of model.Lastly, the construction technology are proposed. The application of formulars is illustrated through a project example, for the sake of the spread of this technology applying in practice project.