Research On The Flexural Behavior Of GFRP-reinforced Ceramsite Aggregate Concrete Beam

The application of ceramsite concrete engineering shows that ceramsite concrete has many advantages in engineering applications and has broad prospects.However,the relevant ceramsite concrete structure design rules in China are not yet mature and perfect,and there is a lack of technical support in practical engineering applications.In this paper,through the experimental study of 11 concrete beams,the mechanical behaviors such as concrete strain,reinforcement strain,cracking load,yield load,ultimate load,deflection and crack development are measured.The load-span deflection curve describes the crack development and compares it with ordinary concrete beams.The main research results include the following aspects:1.Through the four-point bending loading test of the beam test piece,the effects of different reinforcement ratio,aggregate type and reinforcement type on the bearing capacity,stiffness,cracking performance and failure mode of GFRP reinforced concrete beams are compared and analyzed.Influence of grain concrete bearing capacity,stiffness,crack resistance and failure mode will be studied.2.In the test,the strain of the ribs at the crack section and the average strain of the ribs between the cracks were measured under different load levels.The linear regression was used to propose the proposed formula for the strain unevenness coefficient ψ of the GFRP ribs between the fractures.3.The calculation formula of the maximum crack width in the current technical regulations for lightweight aggregate concrete structures is not reflected in the difference between GFRP bars and steel bars.Therefore,this study is based on the calculation method of crack width of reinforced ceramsite concrete,and the GFRP reinforced ceramsite is proposed through experimental regression.The proposed calculation formula for the crack width of concrete,and the calculation results are compared with the calculated values and measured values of the current regulations.The maximum crack width of the GFRP reinforced ceramsite concrete beam is calculated.The GFRP reinforced strain non-uniformity coefficientψ is calculated.Accuracy and reliability.4.According to the existing theory of calculation of flexural capacity,the theoretical calculation values are compared with the experimental values to verify whether the calculation method of GFRP reinforced concrete specifications is still applicable,and the influence of test data on the ultimate failure load of ceramsite concrete beams is obtained.5.Through experimental research,it is verified that the strain non-uniformity coefficient F of the reinforced concrete is used as the parameter,and the stiffness calculation formula of the lightweight aggregate concrete structure technical specification is used to calculate the section bending stiffness of the GFRP reinforced ceramsite concrete beam.The measured deflection value of the ceramsite concrete beam in the normal use stage is compared with the theoretical value to verify the safety and reliability of the formula.