Experimental Study On The Long-term Performance Of Basalt Fiber Reinforced Concrete

In recent years,the country has become increasingly concerned about the ecological environment,as an important building material,concrete desperately needs to improve the performance of green innovation requirements.Basalt fiber reinforced concrete（BFRC）was born in response to the time it was used in an actual project.Currently,its performance characteristics have been studied in various aspects and it is important to study the development of shrinkage and creep based on its mechanical characteristics to promote the widespread use of basalt fiber reinforced concrete.In this paper,the shrinkage of concrete with basalt fiber is investigated,and the main contents and results of the study are as follows.（1）The flowability of concrete under different parameters of basalt fibers（content and length）was investigated by slump tests.The test results show that basalt fibers have a suppressing effect on concrete flowability;the effect of fiber additive on flowability is higher than the effect of fiber length.（2）The mechanical properties of basalt concrete were investigated by mechanical property tests to study the variation of mechanical property parameters of basalt concrete with different parameters of basalt fibers.The results show that the increase in compressive strength of concrete with basalt fibers is small and even slightly decreases;the increase in the amount and length of basalt fibers leads to a significant increase in compressive strength and splitting strength,indicating that basalt fibers have an excellent reinforcing effect on compressive strength.（3）Basalt fibers can inhibit the shrinkage and deformation of concrete.The shrinkage test of concrete with basalt fiber shows that the shrinkage stress of concrete with basalt fiber increases with age,with the rate of increase being rapid at the beginning and slowing down at the end;the shrinkage process is similar to that of normal concrete,but the addition of basalt fiber significantly reduces the shrinkage strain of concrete.Based on the 180d shrinkage strain of the six groups of specimens,the₁ and₂ coefficients for the influence of basalt fiber addition on concrete shrinkage and the influence of basalt fiber length on concrete shrinkage strain were established from the concrete shrinkage prediction model,and the expressions of₁ and₂ as a function of the corresponding independent variables were obtained by fitting the data.（4）Basalt fibers can inhibit the creep deformation of concrete.Through the basalt fiber concrete creep test found that in the load-holding period,basalt fiber on the concrete creep inhibition is not obvious,in the late increase in the amount of fiber and the increase in the length of the fiber can make the concrete creep coefficient reduced.。Based on the results of the 180d creep test,the coefficients₁ for the effect of basalt fiber admixture on concrete creep and₂ for the effect of basalt fiber length on concrete shrinkage strain were introduced on the basis of the concrete creep prediction model,and the expressions of₁ and₂ as a function of the respective independent variables were obtained by fitting the test data.