The Application And Research Of Structure With Semi-rigid Base Course Of Lime-flyash Macadam

According to the real situation of asphalt pavements constructed by semi-rigid base course of lime-flyash macadam was used at the urban area of Oerhtossu Inner Mongolia, and based on the same researching of both home and abroad,the article further discussed some properties of the mixture Of lime-flyash macadam.The aim is1.Determine the correct proportion of lime and flyash,the gradation of aggregates, the ratio of lime flyash to aggregate in the mixture so as to make sure the semi-rigid base course with better mechanical properties and road performance.2.Analyze the forming principle of strength and nail down measures of improving early stage strength of the mixture,e.g.admixture can evidently promote its early stage strength.3.Studied the quality control and measurement for the construction of base course which built by lime-flyash macadam,and indicate the control methods and measurements to the construction of the base course.The researching of the semi-rigid base course,through out aspects of its mechanical property and road performance,including:the quality and demand of raw materials,the gradation of gravel aggregates,the proportion of the mixture,the strength forming theory, and the affection of admixture to strength etc.It also contrasted the mixture performances between using gap-graded aggregate and continuous grading,and put forward the mix design of lime & flyash macadam of which the inlaying compact structure is made.The detailed as following.1.By experimentations of unconfined compressive strength,immersion,water scouring,wetting and drying cycle,freezing and thawing cycle,contrasted,between two types grading crush stone mixture,mechanical properties,water-stability,scour resistance, and durability,then revealed that in all above capabilities of the continuous grading mixture are precede gap-grading mixtures.2.Analyzing microstructure of lime-flyash macadam,confirming its strength forming rationale,then raised methods of increasing early stage strength of lime-flyash mixture.Using electron microtechnic,found that admixture can improve distinctly the mixtures early stage strength,the reason is admixture can alter crystal structure in the mixture.3.Carry out batching design.Applying different proportion of aggregates into same scale L&F(lime to flyash=1:4),by calculating density,void ratio data,finally,through putting dense continuous grading aggregates into proper ratio L&F mixture,it will form the lime-flyash macadam of inlaying compact type.Its mechanical properties and road performance are all satisfied.4.Studied construction quality control and its measuring of L&F macadam semi-rigid base course,and pointed out that for ensure the quality,at different stage of execution of works,we should check following data regularly:compactness,smoothness, and thickness.