PRODUCTION OF ARTIFICIAL LIGHTWEIGHT AGGREGATE, AND ARTIFICIAL LIGHTWEIGHT AGGREGATE OBTAINED BY THE METHOD

摘要

PROBLEM TO BE SOLVED: To provide the method for producing a high strength high quality non-calcining type artificial lightweight aggregate which can easily be produced at a low cost by adding an easily available low-cost additive, and to provide an artificial lightweight aggregate produced by the method. SOLUTION: In this method for producing the artificial lightweight aggregate, coal ash is mixed with a cement, and the obtd. mixture is pulverized and subjected to high pressure steam ageing, or to normal pressure steam ageing and then to high pressure steam ageing. Or, the mixture is pulverized to <=30μm average particle size, preferably <=20μm average particle size. The pulverized material is compacted and aged in steam, and if necessary, calcium sulfate is added to the mixture. The proportion of calcium sulfate is 0.5 to 10 wt.% calculated as CaSO4 . Moreover, the proportion of the cement is controlled to 1 to 50 wt.%. The artificial lightweight aggregate is produced by the method above described has <2.0 bulk density or <10% water absorptivity.