Design and Road Performance Study of Steel Slag Based Road Base Material
To reduce the early cracking problem of asphalt pavement base course in arid and cold regions of northwest China and promote the recycling of industrial solid waste,a graded steel slag mixture is designed,and a composite mineral admixture composed of slag powder,fly ash,and carbide slag is used as a binder to stabilize the graded steel slag,forming a full solid waste steel slag based road base material.By testing the water immersion expansion rate of steel slag,the expansion rate of base material,unconfined compressive strength,dry shrinkage strain,and frost resistance,the stability,strength growth rule,cracking resistance,and long-term stability of steel slag based road base material are analyzed.The results show that the aging effect of steel slag in high temperature season is significant,and the expansion rate of steel slag during the 90 day aging period decreases by a maximum of 38.7％.Spraying water accelerates the aging of steel slag,and the maximum reduction in the expansion rate of steel slag immersed in water increases by 29.1％compared to that without spraying water.Composite mineral admixtures have an inhibitory effect on the expansion rate of steel slag mixture,and the expansion rate decreases by 61.8％when the content is 12％.Graded steel slag mixture gradually develops strength with age.After adding 6％composite mineral admixtures,it is similar to lime fly ash stabilized materials in that its early strength increases slowly and its later strength increases rapidly.At 90 days,its strength is 2.1 MPa higher than that of cement stabilized materials.Compared to the dry shrinkage strain at the age of 30 days,the dry shrinkage strain of graded steel slag mixture is 74％lower than that of cement stabilized mixture,and the dry shrinkage strain of steel slag based stabilized mixture is 20％lower than that of cement stabilized mixture.The frost resistance of steel slag based road base materials is better than that of cement stabilized and lime fly ash stabilized base materials in the later stage.In conclusion,the steel slag based road base material has good stability and long-term durability,and has low shrinkage,which can reduce early cracking of the base in arid areas.
road baseearly crackingsolid wastegraded steel slagcomposite mineral admixture
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