Research And Application Of Low Cement Content Stabilized Graded Macadam Based In Liaoning Province

In this paper,physical and mechanical properties of graded gravel and cement raw materials were tested.The result shows that the raw materials of graded gravel are in line with the requirements of technical specification for construction of highway Pavement.Through the analysis of the strength formation mechanism of the low cement content stabilized graded gravel base material,the reasonable structure type of the skeleton compact structure with low cement content stabilized graded gravel mixture is obtained,which can give full play to the stable gradation of low cement content Gravel base material of the excellent road performance.In this paper,two kinds of gradation types are designed,which are skeletal compact type Ⅰ and skeleton dense type Ⅱ respectively.The maximum dry density and the optimum water content of aggregates with different particle size and different cement contents are determined.This paper focuses on the 7d unconfined compressive strength test,the compressive modulus test,the indirect tensile strength test,the anti-shrinkage performance test,the freeze-thaw test and get the following conclusions:(1)Through the 7d unconfined compressive strength test,when the skeleton dense type Ⅰ cement content reaches over 2.5%,the material meet the "Road asphalt pavement design specification"in the heavy traffic on the pavement base strength requirements;(2)Through the compressive modulus test and the indirect tensile strength test,the compressive modulus of the base material and the results of the splitting strength test were obtained under different cement contents.The results were as follows:The mechanical response analysis of the pavement structure provides the parameters.(3)The shrinkage behavior of low-cement stabilized graded gravel was obtained by the anti-shrinkage test of low-cement stabilized graded gravel,which was as follows:the increase of cement content(from 1%to 5%),test material The shrinkage coefficient and the shrinkage coefficient of the composites are obviously increased.The shrinkage performance of the skeleton type gradation mix is better than that of the continuous gradation mix.Therefore,the choice of reasonable cement content,mixture grade type is to control the stability of cement stabilized grass-roots material basic elements.(4)The water stability test of stabilized graded gravel by low cement dose shows that when the cement content is low,the compressive strength loss is obvious under the freeze-thaw cycle.When the cement content increase from 3%to 5%.The compressive strength increases sharply,the compressive strength loss rate is significantly reduced,the cement content reaches 5%,the base material BDR reached more than 90%,Indicating that the gradation in the high cement content in the freeze-thaw stability is better.At the same time,under the freeze-thaw cycle,the mass change of graded crushed stone is below 0.5%,which shows that the freeze-thaw cycle has little effect on the quality of low-cement stabilized graded gravel base material,and the integrity of the specimen is good.In this paper,ABAQUS finite element numerical analysis software was used to analyze the asphalt pavement structure with low cement content stabilized graded gravel asphalt.The result shows that when the cement content is reduced,the design index value is decreased,but the cement content is too high and the anti-skid performance of the ground is reduced.It can be seen that in the practical application of low cement dose stabilized gravel base,it is necessary to combine the traffic grade,choose reasonable cement content,not only meet the crack resistance of the base material,but also meet the pavement design requirements(deflection requirements,Layer tensile stress requirements).After analysis and calculation,this paper recommends nine kinds of typical structures with low cement dose stabilized graded macadam basement asphalt pavement suitable for light,medium and heavy traffic grade Reconstruction Project and new pavement.The results show that the low cement content stabilized graded gravel based on asphalt pavement which has good performance and effectively inhibit the occurrance of reflective cracks.