Experimental Research On Flexural Performance Of The RC Beams Strengthened With HPF

High performance ferrocement (HPF) technology is a new method to reinforce the concrete structure and masonry structure.The domestic scholar have started to carry out widely experimental study and theory exploration in this domain. But it has not reported the aspect of shear which strengthened by HPF. In order to let this reinforcement technology apply as soon as possible in the project practice, the author and the topic component member spent 12 months, It has spent thorough research on shear-resisting capacity of the actual concrete which reinforced by HPF for the first time from two aspects of the experiment and the theory, it have obtained one batch of corresponding research results. The main achievements of this dissertation are described as follows.(1) Based on the test of 6 RC beams strengthened with HPF (BS) and 1 control member unstrengthened RC beams for comparison (BU), the shear behavior of BS subjected respectively to once and secondary load is investigated. The test results show that the HPF technology can effectively increase the shear strength of RC beams and improve the ductility capacity of RC beams. The failure modes of BS in shear are shear-compression failure and debonding failure. As a whole, cracking formation of BS exhibits the shape of"thin and dense".(2) The shear mechanism of the RC beams is discussed in the paper. It is assumed that the shear mechanism of HPF is consistent with the stirrup, so the contribution of HPF can be investigated by experiments. And the truss-arch model is introduced to analyze the strengthening mechanism of HPF to reinforced concrete beams.(3) The HPF shearing strength theoretical formula has been determined based on the truss-arch model. At the same time, under the premise of clear affects on the factor of shearing strength (initial stress, the HPF reinforcement rate), The simplification practical supporting capacity formula has be proposed based on the present standard, And it confirms the reasonable victories of two kinds of the formula and the test data .(4) It has elaborated the RC beams strengthened with HPF general finite element analysis software ANSYS to establish the three-dimensional model, and has carried on the analysis comparison, confirms the model and parameter selection rationality which established.(5) According to the field test condition and the technical specification for strengthening and code for acceptance of construction quality, the construction technology, quality control method of construction and acceptance of construction quality are proposed.