Deflection estimation of concrete slab reinforced with GFRP bars with consideration of arching action

Li Chunhong1,2,Wei Demin2,Zheng Yu1(1.Department of Civil Engineering,Dongguan University of Technology,Dongguan,Guangdong 523808,China;2.State Key Laboratory of Subtropical Building Science,South China University of Technology,Guangzhou,Guangdong 510641,China)

glass fiber reinforced polymer bar;deflection;arching action;concrete slab;principle of virtual work

In the United States Code for design of concrete structures(ACI440.1—06),the deflections of concrete slab reinforced with glass fiber reinforced polymer(GFRP) bars were often overestimated because of un-consideration of arching action.In order to obtain an accurate deflection estimation method,seventeen concrete slab strips restrained at end were tested with concentrated loads at mid-span until being failed.The results show that arching action becomes gradually significant after cracking.Deflection development can be divided into three stages of before cracking,cracking and forming arching action.Based on the test results of seventeen concrete slab strips and literature report,the arching action was quantified to deduce deflection estimation method by virtual work principle.When the deflections are 1/800 and 1/350 of clear span,the load predicted by ACI are 0.388 and 0.411 times of test result,respectively,while those of proposed method are 0.969 and 1.044.Compared with the prediction by ACI,the proposed deflection estimation has better coincidence with test result.