Experimental Study On Flexural Fatigue Behavior Of Basalt Fiber Reinforced Concrete

With the advantages of excellent mechanical properties and a large scale of production,environmentall y friendl y material basalt fiber can be added into concrete to improve its mechanical properties,making it a high quality building material,which has been applied to various fields of infrastructure construction.In order to gain theoretical support in pra ctical engineering promotion and application,a large number of experiments have been conducted to study the mechanical properties and damage degradation regularit y of basalt fiber concrete in static load and blending fatigue tests.In this paper,basalt f ibers with a length of 3cm are added to the concrete in volumetric amounts of 0%,0.2%,0.3%,and 0.4%,respectivel y,to produce cubic test blocks(100mm×100mm×100mm)and rectangular cross-section trabeculae(100mm.×100mm×400mm),static load test(compres sion test,splitting test and flexural test)and bending fatigue test with two stress levels(0.65 and 0.75).After the static load test,the compressive strength of the concrete decreases when the basalt fiber is added;the tensile strength increases with a reasonable volume content;the flexural strength increases obviousl y,and the corresponding volumetric volume of the corresponding flexural strength is 0.3%,compared with plain concrete,the flexural strength increased by 21.6%.According to the bendin g fatigue test,the fatigue life increases with the increase of fiber volume content,and the fatigue life enhancement effect of high stress level is more obvious when the volume content is added.Compared with plain concrete,the average fatigue life is i ncreased by 37.86 times.The fatigue endurance on the basis of the fatigue theory was in accordance with the two-parameter and three-parameter Weibull distributions.What's more,the P-S-N curve and the fatigue equation were obtained.Based on the anal ysis of maximum strain and the amount of damage,the specific effects of fiber volume content and stress level on the D-? curve were acquired.The law of attenuation was studied by defining the elastic modulus,and the concrete rules of the attenuation rate an d decay span of the elastic modulus under different volume content and different stress levels were found.Finall y,the development law of the maximum deflection of the circulation was explored,and the basic theory about the development of fatigue deflection of basalt fiber concrete was obtained.