| Dry residue is a waste plant or ironworks slag through a dry process to get. The majority emissions and accumulation of dry residue is in the form of solid waste,Because of the very low utilization of dry residue after magnetic separation crushing process. This approach not only occupies the land, but also pollutes the environment. Dry residue has the rolling gravel performance, after crushing, magnetic separation and screening process to obtain. However, dry residue easily swelling expansion characteristics and other factors makes its application in road engineering limited. In order to continue to explore application route of dry residue in road engineering, this study use the dry residue which smaller than 4.75 mm replace part of macadam in semi-rigid. It uses the surface roughness and large internal friction angle characteristics to improve the stability of skeleton. It uses cement, lime, slag powder dry, dry slag aggregate conduct mix proportion design and performance tests. The purpose is to explore a new type of cement-lime-dry residue semi-rigid material.Using unconfined compressive strength test, splitting strength test, flexural strength test and compression modulus tests four experiments to evaluate mechanical properties of materials; It use compressive strength ratio of before and after soaking and freezing to evaluate the water stability and freezing stability. Using shrinkage test, erosion test and expansive test to analyze the durability of cement-lime-dry residue semi-rigid material; It use microscopic electron microscopy test observed dry residue and the resulting material and analyzes the economic benefits and promotion prospects.The results showed that: The best solution proportion of cement-lime-dry residue semi-rigid material is PB-B-60. In this scenario, the cement is 4%, 2% lime, dry slag powder is 3%, dry slag aggregate(<4.75mm) is about 60%. Under this scheme, unconfined compressive strength of the material is 5.38MPa; splitting strength is 0.476MPa; compression modulus is 1451MPa; flexural strength is 2.12MPa; softening coefficient is 0.922; antifreeze BDR is 84.43%; conservation 90 d total shrinkage strain is 0.0193%, the total shrinkage coefficient is 42.881%; first time scouring the amount is 14.22 g, erosion rate is 2.767g/min, respectively, the second period 8.34 g, 1.367g/min; expansion was 0.55%. Dry residue incorporated into the material, both mechanical properties、stability and durability will be affected. The unconfined compressive strength and splitting strength showed first increased and then reduced with the increasing content of dry residue. After it incorporated into reasonably dry residue, on the one hand increases the angle of internal friction between material particles, on the other hand a large number of interconnected pores within the material are formed. Cement hydration products condensed into a mesh cement stone, played fiber reinforced effect, making its strength and overall performance improved. However, due to the dry residue contains a lot of voids and its strength is not as good as quality gravel, the water stability, freezing stability, shrinkage performance and expansion properties will cause negative impact if the dry residue content is too much.This article was studied laboratory experiments of cement-lime-dry residue semi-rigid material. The material pavement performance that we research can meet the basic requirements of highway semi-rigid. The study provides technical support for the the material in engineering applications. The research results will help to the further promotion and application of dry slag in road engineering and achieve the purpose of comprehensive utilization of resources environmental protection. |
PDF Full Text Request