Experimental Study On Cement Stabilized Steel Slag-macadam Design And Road Performance

The semi-rigid base layer is the main load-bearing layer in the pavement structure and is widely used in high-grade highways and urban trunk roads in China.However,the construction of highway projects requires a large amount of macadam,and the exploitation of these macadam will bring tremendous pressure on the ecological environment.As an environmentally friendly material,steel slag has the advantages of high strength and good wear resistance.The use of steel slag for pavement base construction not only reduces the damage of steel slag accumulation to the environment,but also has the ecological damage caused by the relief of macadam mining.Significance.The industrial waste residue of steel slag is fully and reasonably used in a semi-rigid base layer,and has a broad market.This paper aims to scientifically and rationally utilize the industrial waste of steel slag,and comprehensively compare the compressive strengths of 7d of 9 gradation curves of three structures,thus determining the best curve of steel slag;and designing 5 different kinds.The amount of steel slag is compared with the cement stabilized steel slag-macadam strength,elastic modulus,water swell expansion rate,dry shrinkage performance and temperature shrinkage performance of five kinds of steel slag,and the mechanical properties of cement stabilized steel slag-macadam stone are compared.Performance and road performance;combined with SEM scanning electron microscopy to detect the microstructure of different steel slag blends,explain the formation mechanism of strength under different ages,and provide effective parameters for the application of cement stabilized steel slag-macadam in physical engineering.The results show that the compressive strength of the mixture with the fine structure of the skeleton compact structure is the largest,and the strength of the 7d can reach 5.94MPa.the strength of the cement stabilized steel slag-macadam stone increases with the incorporation of steel slag.When the steel slag content is 75%,The strength of the mixture is the largest,the strength of the 60d can reach 13.4MPa,the coefficient of dry shrinkage of the mixture decreases with the increase of steel slag.When the amount of steel slag is 25%,50%,75%,100%,respectively,the shrinkage coefficient is respectively Reduced by 9.4%,27.8%,35.2%,46.2%,the incorporation of steel slag helps to improve the crack resistance of the mixture;the cement stabilized steel slag-macadam stone with temperature lower than-10℃ with the temperature decrease.The temperature shrinkage coefficient increases,and the temperature shrinkage coefficient decreases with decreasing temperature in a low temperature environment below-10℃.The incorporation of steel slag helps the cement to stabilize the formation of gels in the steel slag-macadam,and the flocculent and rod-shaped gels connect the aggregate particles together to form a dense whole and improve the road performance of the mixture.The test road results show that the cement stabilized steel slag-macadam capacity is better than cement stabilized macadam,and the social,economic and environmental benefits brought by steel slag in highway engineering are obvious.