Study On The Property Of Lime-fly-ash Bound Macadam Joined With Steel Slag

The Semi-rigid Base course material made of Lime-fly-ash bound macadam has been widely used in highway construction of China for its high workability and notable economic benefits. But, for the performance of material, cracks often occur in the lime-fly-ash bound macadam base due to the dry-shrinkage and temperature-shrinkage during the stage of highway business. As a result, the applicable properties of Semi-rigidity bituminous pavement and the service life of highway may be weakened. Steel slag, an industrial waste slag, has been widely used in highway construction gradually for its strength same as natural stone and the properties of expansion. But it has not widely used in the Semi-rigid Base course material as a component. Based on the Steel slag of Steel slag company in MA AN SHAN , the Semi-rigid Base course material made of Lime-fly-ash bound macadam joined with different size Steel slag in lab tests has been studied on. The study focuses on the change of unconfirmed compressive strength, splitting tensile strength, modulus of compressive resilience and dry shrinkage property after the fly-ash partially replaced by Steel slag and the macadam replaced by the same size steel slag. Based on the test, the conclusion was driven that :1,The strength and the rigidity of mixtures increase in the first and decrease in the last with the content of small size Steel slag increasing. The experimental results show that it can mainly enhance the strength and the rigidity of mixtures when the proportion of small size Steel slag replacing the fly-ash is proper (ratio of Steel slag and fly-ash is 1:2); The strength and the rigidity of mixtures increase with the content of large size Steel slag increasing. 2,When the proportion of small size Steel slag replacing the fly-ash is proper(ratio of Steel slag and fly-ash is 1:2), it can mainly weaken the dry shrinkage of mixtures but the large size Steel slag can't .The expansion rate of Steel slag with steam test is researched in this paper too. Based on the test, the reason that the dry shrinkage of the Semi-rigid Base course material has been weakened after Steel slag joined is aided analysis by the expansion rate of Steel slag. The experimental results show that the smaller particle size of Steel slag the larger value expansion rate is. The engineering application of the Lime-fly-ash bound macadam joined with Steel slag has also been discussed. Using this product widely in the construction will bring the great social and economic benefit forth.