Experimental Research On Recycled Mixed Aggregate Used In Road Graded Crushed Stone Subbase

Compared with some developed countries such as Europe,America and Japan,the resource utilization rate of construction waste in my country is still relatively low at present,and the treatment methods are mostly extensive treatment methods such as open-air stacking and landfilling.If things go on like this,the cumulative amount of construction waste has reached an alarming number,which has had a greater impact on the development of the city and the appearance of the city.Therefore,it is extremely important to seek a solution to construction waste,which is related to my country’s economic benefits and is also in line with my country’s sustainable development strategy.Although after theoretical research,recycled aggregate has been strengthened and has good working performance.However,it has inevitably brought about an increase in construction costs,which caused an embarrassing situation in the use of construction waste.This research group has studied the crushing characteristics of dry recycled aggregates,and further studied the method of determining the gradation of recycled mixed coarse aggregates for road bases or subbases.This article is based on previous research,first of all,based on laboratory experiments,continues to supplement and improve the existing experimental conclusions,and supplement the crushing characteristics of saturated recycled aggregates.After that,based on the results of indoor tests,the recycled aggregate was innovatively used in the actual engineering of the pavement subbase.Combining mechanical and physical indicators to detect the pavement subbase layer,and analyze the measured data results.Different from previous actual engineering cases,this test considers the practical significance of the test more.Instead of using recycled aggregates with good grading and complete crushing,the recycled aggregates with incomplete crushing degree are used for the sub-base layer of the pavement.Filler.As a result,a high-efficiency,low-cost,and feasible way of using construction waste has been found.After comprehensive analysis of indoor and outdoor test results,the following research results are obtained:(1)The compressive strength of the recycled mixed aggregate in the saturated state is lower than that in the dry state.However,the impact of strength on the crushing of recycled aggregates is far greater than the impact of moisture content on the crushing of recycled aggregates.And the fractal dimension is negatively correlated with the strength of recycled aggregates,that is,the greater the strength of the aggregate,the smaller the value of the fractal dimension D;the smaller the strength of the aggregate,the greater the value of the fractal dimension D.Therefore,the fractal dimension D value can also accurately characterize the strength of the aggregate.(2)Whether it is in a dry state or a saturated state,the crushing of the aggregate can improve its gradation.As the pressure increases,the recycled aggregate changes from a single particle size to a relatively good particle size,which further improves the compressive strength of the recycled aggregate.(3)The incorporation of recycled brick aggregate can improve the performance of the aggregate,increase the stability of the skeleton of the recycled aggregate and the degree of compactness,so as to obtain better working performance.The field test phenomenon is in line with the conclusion of the indoor test,that is,as the loading pressure increases,the aggregate will change from a single particle size to a good particle size,and the crushing of the aggregate improves its own particle size gradation.(4)The advantage of recycled mixed aggregate is to make full use of the advantages and disadvantages of different aggregates,to ensure the full use of the advantages of recycled concrete aggregates.