Effects Of Humidity Environment On Durability Of GFRP Bar In Concrete

In recent years,as GFRP bars are widely used in the field of civil engineering,the problems about durability of GFRP bars in engineering are increasingly concerned.And a number of studies related to these issues are conducted.Due to the durability of GFRP bars could be seriously affected by internal alkaline environment of concrete.So it is very necessary to perform the study of durability of GFRP bars in concrete.However,the accelerated testing in laboratory is being mostly in a simulated pore solution of the concrete and rarely in a real concrete condition,while little durability test of GFRP bars is conducted under the environments of different humidity.Thus,this paper performs a experimental study on durability of GFRP bars in concrete,which is under different humidity environments.A large number of the relevant literature,specifications and standards of GFRP bars are consulted in this paper.And we design the size of test specimens and molds,which are combined with demands of the test.Then developed a reasonable test processes.Resistance value of concrete is studied in this study.more specifically,the study is on the resistance value of concrete at different depths(17mm,47 mm,62mm)of 154 mm diameter cylindrical concrete,and under three different ambient relative humidity(65%,85%,95%).And the study on tensile strength of GFRP bars in the diameter of 154 mm and the length of 200 mm cylindrical concrete is also performed,which stay in the external environment that relative humidity of 65%,85% and 95%,lasting for one,two,three and four months respectively.The results is that the resistance value of concrete obviously different in a variety of humidity environments;tensile strength of GFRP bars has a large decline in the first aging month,especially under the environment of relative humidity of 95%.