Experimental Research On Flexural Performance Of GFRP Bar Reinforcing Sea Sand Concrete Beam

Excessive exploitation of river sand has had a serious impact on the ecological environment.Using sea sand to replace the river sand in traditional concrete can solve the problem of lack of river sand resources.However,sea sand contains a large amount of chloride ions,which strongly corrodes steel bars.Therefore,the application of sea sand concrete is limited,and glass fiber reinforced polymer(GFRP)has excellent corrosion resistance and strong tensile strength.In actual engineering,if sea sand is used instead of river sand,and GFRP bars are used instead of steel bars in concrete structures,it can not only solve the impact of river sand over-exploitation on the ecological environment,but also solve a series of problems caused by steel corrosion.Different from steel bars,GFRP bars are linear elastic materials and have no yield point.After reaching the tensile strength limit in the structure,they will break without any signs.This feature makes GFRP bars in concrete structures unable to be as suitable as steel bars.In this paper,6 sea sand concrete beams are designed,including 4 GFRP reinforced sea sand concrete beams and 2 reinforced sea sand concrete beams.The flexural performance of the test beams is studied.The main research contents are as follows:1.Through the sea sand concrete cube compressive test and split tensile test,the physical and mechanical properties of sea sand concrete are studied.The research results show that the physical and mechanical properties of sea sand concrete are almost the same as those of ordinary concrete.Therefore,the combination of ordinary concrete It is completely suitable for sea sand concrete;2.The flexural performance of GFRP bars sea-sand concrete beams with different reinforcement ratios and different concrete strength grades was studied,and compared with two reinforced sea-sand concrete beams of the same strength grade,from the cracking load,the ultimate load,and the crack analyze the performance of the test beam in development and other aspects,and revise the calculation formula for the bearing capacity of the GFRP bars sea sand sea sand concrete beam;3.The deflection of sea sand concrete beam of GFRP tendon is analyzed,calculated using the calculation formula of ACI-440 specification,and compared with the measured deflection.The results show that the method is better in predicting the deflection of the test beam;4.Analyze the test beam based on DIC(Digital Image Correlation)technology and compare it with the traditional displacement meter.The DIC measurement range is larger,and the strain and displacement of all positions of the entire test beam can be obtained,which is compared with the traditional measurement method.The displacement curve is very close,indicating that the DIC measurement technology has high accuracy and is very convenient to use.It does not require a lot of manpower and material resources for measuring point layout and data collection.