Experimental Study On Fatigue Damage Evolution Law Of Cement Stabilized Macadam During Construction Period

Cement stabilized gravel is the main material for semi-rigid asphalt pavement base.Its advantages are high strength,low cost,and overall good performance of the pavement.However,the strength of cement stabilized gravel increases slowly and the curing period is long.Actual construction cannot wait until its strength is complete.Exercising and then proceeding to the next step,often open the heavy-duty construction vehicle at the early stage of curing and the strength is still very low,and carry out the construction of the next step,which leads to premature damage to the cement stabilized macadam base,and the overall strength is significantly reduced.The actual intensity after traffic is far below the laboratory test level,and the actual performance of the road surface is significantly lower than expected.Therefore,study the fatigue life and damage evolution characteristics of cement stabilized gravel in different curing periods,evaluate the adverse effects of construction damage on its strength and modulus in the early period of curing,and grasp the coupling law between the strength growth of cement stabilized gravel and construction damage during the curing period.Estimating the level of increase or decrease in its strength and modulus is critical for accurately calculating the pavement mechanics response and objectively evaluating the performance of the pavement.In view of this,this article first tested the indirect tensile and unconfined compressive strength of cement stabilized macadam with different curing ages,and obtained the development law of the strength of cement stabilized macadam with its age;then on this basis In addition,the indirect tensile fatigue test was used to study the fatigue damage evolution of cement stabilized crushed rock under different curing ages,different load levels and different loading frequencies;finally,based on the test results,the establishment of cement stabilized crushed stones of different ages The theoretical model of fatigue life and damage evolution of stone,and the model was verified.The results of the paper show that the initial strength and fatigue life of cement stabilized crushed stone are very small,and the load of construction vehicles will cause serious damage to it;the damage evolution model built in the paper can better reflect the damage evolution rate of the curing time,load level,and loading frequency.And fatigue life,and the model calculation results are generally in good agreement with the test results,which can better reflect the size of the damage caused by the construction load during the curing period to the cement stabilized macadam base.