Research Of Coal Cinder And Using It As Concrete Admixtures

Coal cinder was a solid waste generated by industrial coal-fired equipment, more than one hundred million tons of one year.At present utilization of coal cinder was low,some used for making bricks and paving road,others random stacking, not only took up a lot of land, emissions of sulfur gases will pollute the atmosphere and endanger the environment.In recent years,using solid waste making building materials belonged to green energy-saving technology,which was supported by government. Chemical composition and mineral of coal cinder powder was similar with fly ash, but fly ash has been widely used in building materials,becoming an indispensable raw material prepared for high performance concrete for many years.Recent research had showed that the activity of coal cinder powder was likely to exceed fly ash,The purpose of this paper is to study the basic physical and chemical properties of coal cinder powder, and study it as admixture for high performance concrete.(1) X-ray diffraction, scanning electron microscopy were used to study the physical and chemical properties of coal cinder powder;(2) By using mechanical activation,the activity index of coal cinder powder accessed to 124.17%;(3) Of all the selected chemical activators, the stimulation effect of dihydrate gypsum was better,and the best content was 1%;(4) Due to higher activity of coal cinder powder, when it combined with other admixtures, compressive strength was down, but liquidity increased;(5) The compatibility tests of coal cinder powder and superplasticizer showed that coal cinder powder and superplasticizer had good compatibility.Its saturation point was the same to fly ash of gradeâ…¡;(6) Compared with othe admixtures with the same content at 30% for high performance concrete, coal cinder powder concrete had higher compressive strengh;(7) Prepared 80MPa high strength coal cinder powder concrete, the combination that 20% coal cinder powder+10% blast furnace slag+1% gypsum gained good capability of workability, the highest compressive strength and better resistance to chloride ion penetration.