不同膨胀剂在制备污泥、粉煤灰-页岩高性能轻骨料中的作用

Effects of Different Swelling Agents on Sludge and Fly Ash-shale High-performance Lightweight Aggregates Preparation

研究了不同膨胀剂对污泥、粉煤灰-页岩轻骨料性能的影响,制备了高性能轻骨料.设计配方中选择了三种膨胀剂,比较了不同膨胀剂的作用效果,分析了导致轻骨料膨胀率、颗粒强度变化的原因.结果表明:SiC有较强使轻骨料在焙烧时产生膨胀的作用;CaCO3在研究的条件范围内,不能有效的使轻骨料产生膨胀;SiC与CaCO3复合膨胀剂可以使轻骨料在焙烧时膨胀,膨胀率可达到58.28%,添加复合膨胀剂的轻骨料膨胀率普遍低于添加SiC.当污泥掺量为35%、粉煤灰掺量为19.5%、页岩掺量为45.5%,添加复合膨胀剂的轻骨料在1160℃焙烧后,颗粒强度达到11.6MPa,24h吸水率小于1.0%,表观密度为1 090kg/m3,满足轻质高强低吸水高性能轻骨料的要求.

To investigate the effects of different swelling agents on the performance of sludge and fly ash-shale lightweight aggregates,and to prepare high-performance lightweight aggregates,in formula design,3kinds of swelling agents were selected and their effects were compared,and causes of the changes in swelling ratio and particle strength of lightweight aggregates were analyzed.Results showed that SiC had a strong swelling effect on lightweight aggregates during calcinations;CaCO3 was ineffective to produce swelling in light aggregates under the conditions of this study;SiC and CaCO3 compound swelling agent could produce swelling in lightweight aggregates during calcinations,with swelling ratio reaching up to 58.28%.In addition,the swelling ratio of lightweight aggregates added with compound swelling agents was generally lower than that added with SiC.Moreover,with a sludge content of 35%,a fly-ash content of 19.5% and a shale content of45.5%,particle strength reached 11.6 MPa,24 hwater absorption rate was less than 1.0%,and apparent density was 1,090kg/m3 in the lightweight aggregates added with compound swelling agents after calcinations at 1,160 ℃,which all met the requirements of high-strength,low-water absorption and high-performance lightweight aggregates.