Study On The Effect Of Water And Temperature On Fatigue Property Of Cement Concrete Pavement

Cement concrete pavement in the field of our country's road construction mainstay role,its advantage is stiffness big,long service life,have good flatness,at the same time the limestone and need relatively rich resources in our country,and the research to be promoted.At present,the actual service life of cement concrete pavement is often difficult to reach the design life,so it is very important to study its fatigue property.Especially considering water,environmental temperature change is more important to the long-term performance of cement concrete pavement.In this paper,the effects of water and temperature on the fatigue performance of cement concrete pavement are studied.This paper mainly adopts laboratory test,theoretical analysis,engineering analysis and other methods to carry out research.The main research content is the analysis of raw material performance of cement concrete and the design of mix proportion.Experimental analysis of physical and mechanical properties of cement concrete;Study on fatigue property of cement concrete under different environmental conditions;Prediction of fatigue life of cement concrete pavement.The following main conclusions are drawn from the research:The cement concrete mixture ratio of the pavement intensity required to meet the heavy traffic load grade is obtained through the mix proportion design,Cement: sand: gravel: water = 1:1.62:3.44:0.41.The 28 d compressive strength of cement concrete after 28 d was measured by test,and the strength of 28 d was 5.312 MPa,and the water absorption rate of 28 d was 1.31%.Set up the standard curing,freeze-thaw cycle,alternating temperature,water alternating four kind of different environmental conditions,obtained by trabecular bending fatigue test under different environmental conditions stress size is 4.250 MPa,3.984 MPa,3.718 MPa,the fatigue life under 3.453 MPa.The corresponding stress-fatigue equation is fitted with the fatigue life mean of the stress at all levels,and the corresponding fatigue equation curve is analyzed.Through the verification,the data of the fatigue test of the trabeculae under four environmental conditions are well complied with the weibull distribution of the two parameters.Adopted Palmgren-Miner rule analysis of pavement fatigue cumulative damage: the stress of the cement concrete pavement by ANSYS model to analyze its maximum bending tensile stress,according to the stress values corresponding to the fatigue life of its corresponding damage cumulants are obtained.The cement concrete pavement is obtained without considering the environmental conditions,and consider the freeze-thaw damage,alternating temperature,under the influence of the water alternating forecast service life were 22.89,1.73,6.11,25.19 years.Research of this paper to the existing cement concrete pavement fatigue performance prediction method to supplement,rich in freezing and thawing cycle,alternating temperature under the action of environment conditions,such as cement concrete fatigue performance of experiment data,and improve fatigue life of cement concrete correction analysis forecast precision,has certain practical value and research prospects.