The Study Of The Fly-Ash-Flushed-by-Seawater Is Used In The Road Subbase Course

Recently, the fly ash having been built in road construction and having been made in cement largely, caused this industry waste residue to be day by day scarce, and it's price group climbed. Liaoning (Yingkou) Coastal Industrial Base's road construction needs 6,000,000 tons fly ash. The local fly ash which meet the standard requirement,is short.But there are 10,000,000 tons fly ash flushed by seawater (also to call fly-ash-flushed-by-seawater) in storage pool in Bayuquan power plant of Yingkou. It has never been used for road construction. If the fly-ash-flushed-by-seawater can be applied successfully in road construction, the resources will be saved and the environment will be protected.Because there is no report about appling this material for road construction in domestic and foreign until now, and no technology standard can be refered to, this paper, taking the road construction of Liaoning (Yingkou) Coastal Industrial Base as a backing, has researched the fly-ash-flushed-by -seawater how to be applied in pavement roadbase. The main research content and the achievement are as follows:1 .The study about physics mechanical properties of the fly-ash-flushed-by-seawater.The chemical composition of the fly-ash-flushed-by-seawater in Bayuquan is:SiO₂+Al₂O₃ content is greater than 76% and the ignition loss is 3.16%, satisfing the road construction specification.It's grain size can not satisfied the road construction specification and the fly-ash belongs to the low active fly ash. The chloride ion content of the fly-ash-flushed-by-seawater is about 0.80%2.The mixture ratio design of the Lime fly-ash-flushed-by-seawater stabilized crushed-stones includes: (1)the aggregate's grading envelope, (2)the proportion of cement to fly-ash-flushed-by-seawater and the proportion of lime to fly-ash-flushed-by-seawater; (3)the proportion of bound materials to aggregate.This research recommends the best mixture ratio of the roadbase for Yingkou Coast Industry Base as following :the two ash stabilized roadbase,the cement: fly-ash-flushed-by-seawater: stone =5: 10:85; the three ash stabilized subbase, cement:Lime: fly-ash-flushed-by-seawater: stone is 2:10:43:45.3.The hydration reactions theory research of cement and fly-ash-flushed-by-seawater includes following two aspects: chemical reaction analysis of fly ash and cement, and of chloride ion in fly-ash-flushed-by-seawater. Through the microscopic analysis by SEM and XRD, the mix material's strength change regular for different chlorine salt content can be disclosure.4.In order to study the salt content in fly-ash-flushed-by-seawater how to influence the road performance of the two ash stabilized roadbase and three ash stabilized roadbase, this article has done the experiments of roadbase and the subbase as follow: compressive deformation strength experiments, anti-freeze performance experiments ,dry shrinkage performance experiments, temperature shrinkage performance experiments and anti-erosion property experiments.(1) In compressive deformation strength aspect, the chloride ion content in the two ash stabilized roadbase and the three ash stabilized roadbase has an agent function to the early strength, and reject the later period intensity growth. When chlorine salt content in two ash stabilized crushed stones is not big, it is advantageous to the intensity.when the salt content in fly-ash-flushed-by-seawater is big, it is disadvantageous to two ash stabilized crushed-stones's early strength.(2) In anti-freeze performance aspect, the salt content do not change too big to the roadbase material.If the salt content in fly-ash-flushed-by-seawater is big, the subbase material's anti-freeze performance can be affected. Through the anti-freeze performance experiments,we found that if the chlorine salt content surpassesl.5%,.the anti-freeze performance of the three ashes stabilized crushed-stones can't meet the standard requirement.(3) In dry shrinkage and temperature shrinkage performance aspect, it is not big influence in the salt content to the base and subbase blends.(4) In anti-erosion property experiments, the rate of mass loss grows quickly than the salt content grows. This show the anti-erosion performance of the roadbase and subbase material.is sensitive to the salt content in fly-ash-flushed-by-seawater.5.Through the mechanics analysis of fly-ash-flushed-by-seawater stabilized roadbase and subbase with multi-layered elasticity layered system,we can proved that the fly-ash-flushed-by-seawater stabilized roadbase and subbase, under the standard axial loading, can satisfy the design request.6.Through the construction and examination to the experiment road, the key technologies and the technical specification is summarized for Liaoning (Yingkou) Coastal Industrial Base fly-ash-flushed-by -seawater stabilized road construction. And through detection to the experiment road, the fly-ash-flushed-by -seawater stabilized roadbase and subbase are proved to meet the standard requirements.Lastly ,the typical pavement structure for the fly-ash-flushed-by -seawater is recommended in this paper.