Effects of Fly Ash on the Properties of Compound High Performance Lightweight Aggregates

High performance lightweight aggregates are prepared using shale and fly ash.Test selection content of fly ash are 25%,30%,35% and 40% respectively,test calcination temperature are 1140 ℃,1150℃ and 1160 ℃ respectively.With the amount of fly ash increasing,strength of lightweight aggregate particle is improved.The strength of lightweight aggregate particle with 40% fly ash and calcined at 1150℃ can achieve 9.5MPa,apparent particle density can achieve 1060kg/m3,and 24 hours water absorption rate is 2.5%,which meets the high performance lightweight aggregates demand.The surface vitrification degree of lightweight with 40% fly ash and calcined at 1160℃ is higher,24 hours water absorption rate is only 2.2%.Research shows that adjustment of high performance lightweight aggregates could be achieved by the addition of fly ash and calcination temperature.