| In this paper8recycled aggregate concrete beams are produced, one of them is reservedas contract beam at room temperature. First of all, high temperature tests are conducted due to7beams(pre-heating temperature were400℃and600℃), and then using CFRP on4damaged beams for shear strengthening, last monotonous static load tests are carried out forall the beams, main parameters of the experimental study are heating temperature anddifferent reinforcement methods, the test results show that:(1) Compared with the beam under normal temperature, the ultimate bearing capacity ofrecycled aggregate concrete beam has decreased in different extent after high temperature,especially the beam of L8which the heating temperature is600℃and pressure area is underhigh temperature has the largest decline, reaching25.2%.(2) For beams of heating temperature is400℃,the shear capacity is significantlyincreased after reinforced with two different CFRP paste methods. In terms of the increasingextent, adopting the way of U-wrap and layering slightly bigger than strip and layering.However, for beams of heating temperature is600℃, the effect is basically the same afterstrengthened with two types of CFRP paste methods, and are all close to the beams of thatwithout wrapping after high temperature, indicating that now recycled concrete has beenseriously damaged, and barely strengthened with CFRP is infeasible.(3) Both for heating temperature is400℃and600℃, the ultimate deformation capacityof high temperature-damaged beam with bonded CFRP improves obviously.According to “Technology Specification of CFRP Reinforcement for ConcreteStructure†and relevant literature, that theoretical CFRP reinforcement can apply to recycledaggregate concrete beams was well proved. Compared with the calculated values andexperimental data, it indicated that the values calculated by specification is conservative, atthe same time the calculated values have a certain safety margin. |
