Effect Of Steel Fiber And PVA Fiber On Mechanical And Abrasion Resistance Performance Of Ultra High Performance Concrete

China is currently the world's largest cement producer and concrete consumer.Due to the lack of understanding of the complex and varied service environment and extreme conditions,the important structural performance is degraded in advance,resulting in waste of resources and environmental pressure,resulting in huge repairs and Maintenance costs.As one of the main damages of hydraulic concrete,anti-wearing damage is a hot problem in the current research and it needs to be solved urgently.Ultra-high performance concrete,as a new generation of engineering materials,has many excellent mechanical properties and ultra-high durability of traditional concrete materials.This paper aims to blend steel fiber and PVA fiber with different volume fractions in ultra-high performance concrete.The mechanical properties and anti-wear properties of ultra-high performance concrete blended with fiber were studied.The role of two different fibers in ultra-high performance concrete was evaluated comprehensively.At the same time,the compressive strength and anti-wear of ultra-high performance concrete were Intensity is compared to study its intrinsic connection.The main research contents and related conclusions are as follows:(1)The mechanical properties of UHPC of steel fiber and PVA fiber were tested,including compressive strength,flexural strength,tensile strength,splitting tensile strength and bending toughness.The results show that the mechanical properties of UHPC are more obvious in steel-doped fiber,and the mechanical properties of UHPC increase more obviously with the increase of steel fiber content.When the steel fiber content is 3.0%,it is more unfibered UHPC phase.The compressive strength increases by 60%,the flexural strength increases by 59%,the tensile strength increases by 120%,the splitting tensile strength increases by 141%,and the peak deflection and peak load also increase accordingly.PVA fiber incorporation into UHPC mechanics The performance improvement effect is not significant,and even decreases with the PVA incorporation of UHPC compressive strength and flexural strength.(2)The steel fiber and PVA fiber were subjected to abrasion resistance test,and the UHPC abrasion resistance performance was evaluated by the wind sand gun method.The test results show that with the increase of the amount of steel fiber and PVA fiber,the UHPC abrasion resistance strength increases.When the steel fiber and PVA fiber content reach the maximum amount selected by the experiment,the UHPC abrasion resistance strength increases by 29.8 and 53.6% respectively,overall,the abrasion resistance strength of PVA fiber UHPC is better than that of steel fiber UHPC.(3)Comparing the relationship between compressive strength and abrasion resistance strength of steel fiber and PVA fiber UHPC,the comparison results show that the steel fiber UHPC has the correlation between the abrasion resistance and the compressive strength,but it is not proportional to the relationship,while the PVA fiber UHPC is the fiber content.When it is more than 0.5%,it is positively correlated.Overall,the compressive strength of PHP fiber UHPC is not directly related to the abrasion resistance.Comprehensive analysis of steel fiber UHPC and PVA fiber UHPC shows that the steel fiber UHPC compressive strength is much larger than the PVA fiber compressive strength,but the steel fiber and PVA fiber anti-wear strength is not much different,even the maximum amount of PVA fiber abrasion resistance,The strength is higher than the steel fiber UHPC.