Study On The High Performance Concrete Of Hybrid Fiber And Thermal Curing Technology

Cement concrete is an important road pavement material.In the opening sections,we hope its strength as early as possible to meet the requirements of traffic.So the study of ultra-early-strength concrete is significant.To improve the early strength of concrete and ensure the stability of post-performance concrete.The paper modify the material by early strength superplasticizer,different types and scales of hybrid fiber,on this basis,doing a series of studies.Firstly,this paper determine the early strength of concrete mix reference work,through the experiment,we have the following conclusions:(1)The incorporation of silica fume can reduce the construction of concrete significantly.Mineral admixture concrete’s late strength increased significantly,but the strength is lower than ordinary concrete at first day.(2)Single steel fibers added to the concrete can effectively improve the tensile strength and toughness,compared to ordinary concrete the single steel fiber reinforced concrete 1d flexural strength’s most significant upgrade is 35.3%,the minimum margin improvement is 5.04%,28 d flexural strength compared to ordinary concrete can improve 34.7% at most.Single steel fiber reinforced concrete strength grow slowly in the short age,but can maintain stable growth later.(3)With the increase of steel fiber content,its early strength has no obvious rule,but later the strength can be significantly improved.(4)Polypropylene fibers,polyethylene fibers can be incorporated to improve concrete flexural and compressive strength at a certain extent,the 1d concrete flexural strength of incorporation of 0.15% 19 mm polypropylene,12 mm polyvinyl alcohol、19mm polyvinyl alcohol can increase 4%,9.3% and 16.6% compared with ordinary concrete.(5)After comparative study of single、binary and ternary steel fiber concrete,find the optimal ratio of mechanical properties of concrete is the steel fiber reinforced concrete with ordinary steel fibers and ultra-fine steel fiber in a 1: 1 binary under conditions of total fiber content of 1.5%.Its early and late strength are the highest,1d flexural strength 7.04 MPa,7d flexural strength 8.27 MPa.Compared to Single-Mixed steel fibers concrete of 1.5%,Its 1d,7d flexural strength increased by 38.58%,39.69%.(6)Through the analysis of the confounding effect of hybrid fiber reinforced concrete,can found most binary and ternary hybrid fiber reinforced concrete are showing positive confounding effect;the confounding effect of total fiber content of 1.5% of is better than 1.0%,and 1: 1 ratio is best among them.The formulation of concrete 1d,3d,7d flexural strength are higher than all of 1.5% single steel fiber reinforced concrete.Comparing to ordinary steel fiber,ultra-fine steel fiber,short and ultra-fine steel fiber reinforced concrete short,the fiber concrete’s flexural strength improved 38.58%,19.34%,41.08% at 1d.(7)We can obtain by ASTM Flexural toughness test results that Steel fibers can greatly enhanced bending toughness of concrete.Papers also used Japan JSCE bending toughness method,it can be seen fiber flexural toughness of reinforced concrete improve significantly early and late.(8)Comparing fracture toughness of concrete data,we can find that ultra-fine steel fiber reinforced concrete and ternary hybrid fiber reinforced concrete has good fracture toughness.Fracture toughness of ordinary steel fibers and ultra-fine steel fiber doped binary complex of concrete slightly lower than both,But unstable fracture toughness increase to ordinary concrete.(9)By the study of temperature curing method with two different concrete water reducer,we can find,the concrete intensity decreases with the temperature increase above 20 ℃.After curing 20 h,flexural strength of 40 ℃,50 ℃,60 ℃ decreased by 15.06%,12.5%,21.04% compared to the normal temperature(20 ℃).(10)Health studies have shown that temperature is not conducive to improving the flexural strength of concrete to the fiber ultra strength concrete.This is different from Study on concrete temperature.In particular,it should be noted that,Compressive strength of concrete is increasing,but the flexural strength is decreasing.When we use hot health technology,we must take flexural strength as evaluation index In terms of pavement concrete.It can have a wrong result when we take compressive strength as evaluation index.We use Ultra-early strength superplasticize and fibers mixed to reinforce concrete,and improve the performance of concrete strength and toughness effectively.It provides an important reference to the research on high performance concrete.