Experimental Study On Shear Performance Of Basalt Fiber Concrete Beams Without Stirrup

Reinforced concrete is widely used in building structures due to its good plasticity and high compressive strength,but its easy cracking and low tensile strength are one of the major factors restricting its development.Nowadays,it is a kind of research direction to add basalt fiber into ordinary reinforced concrete matrix.In this paper,the shear behavior of basalt fiber reinforced concrete beams without ventral tendons is studied by setting three specimens with 0.1%basalt fiber content and one ordinary concrete specimen.The main research contents and conclusions are as follows:（1）Basalt fiber reinforced concrete beams in shear process,cracks emergence and development of the whole presents the characteristic of the "night,dense,set".During the trial,basalt fiber reinforced concrete and ordinary concrete composite beam failure mode is still the ultimate shear brittle failure,and all the failure modes of fiber reinforced concrete beams is flexural failure,shows the characteristics of obvious ductility.（2）Basalt fiber can improve the ultimate bearing capacity of normal section and inclined section cracking load and crack load.The body uses part of basalt fiber reinforced concrete beam specimens,basalt fiber on the ultimate bearing capacity of the beam body and inclined section cracking load did not reflect the increase.On the ductility of it,both basalt fiber reinforced concrete and ordinary concrete composite beams and the fiber reinforced concrete beams,basalt fiber added to improve the artifacts.（3）In the calculation of oblique section cracking load of concrete beam,combined with the existing theoretical calculation of oblique section cracking load of fiber reinforced concrete beam,the results show that the existing theoretical calculation results and experimental results are in good agreement on the whole.（4）The basalt fiber concrete constitutive equation fitted by Wang Yanling and Zeng Guofan is used in this paper.It can be seen from the ABAQUS simulation results and the final failure form of the test results that the basalt fiber concrete constitutive equation is reasonable.From the point of view of ultimate bearing capacity,the conventional concrete beam and the all-fiber concrete beam agree with the experimental results,while the basalt fiber concrete beam and the composite beam of ordinary concrete have a deviation from the experimental results.Combined with the current calculation theory of ultimate bearing capacity,the calculation result of shear ultimate bearing capacity of inclined section is conservative.（5）The shear span ratio is an important parameter affecting the shear capacity of concrete beams without belly reinforcement,basalt fiber added into concrete matrix can improve the shear performance of members,but the effect of improvement is not as obvious as stirrups.Therefore,in order to avoid the inclined section brittle failure of basalt fiber concrete beam,the best way is to configure stirrups.