掺CFB粉煤灰超微粉水泥性能研究

采用煤矸石电厂CFB粉煤灰超微粉等量替代水泥制备水泥胶砂试样,研究了所制备胶砂试样的抗压强度和抗冻性、耐弱酸腐蚀性能,并考察了不同减水剂对掺CFB粉煤灰超微粉水泥胶砂试样的适应性。试验结果表明,随着CFB粉煤灰超微粉掺量的增加,水泥胶砂试样的28 d抗压强度呈现先增长后减少的趋势,其中掺量为20%CFB粉煤灰超微粉水泥胶砂试样的28 d抗压强度最高,达到了48.5 MPa。与无CFB粉煤灰超微粉掺和的水泥胶砂试样相比,掺20%CFB粉煤灰超微粉水泥胶砂试样的25次冻融循环试验强度损失率减少约76%;48 h耐弱酸腐蚀试验质量损失率减少约36%。不同减水剂对水泥胶砂试样的适应性试验发现,萘系减水剂对掺CFB粉煤灰超微粉水泥胶砂的减水效果好于聚羧酸系减水剂,加入1.5%萘系减水剂后,其减水率可以达到22%左右。

Properties of mortar specimen with the incorporation of ultrafine CFB fly ash

Using the ultrafine CFB fly ash collected from the coal gangue power plant to prepare the mortar specimens.The compressive strength,frost resistance and weak acid corrosion resistance of the specimens were studied,and the adaptability of water agent on mortar specimen containing ultrafine CFB fly ash was also analyzed.The test results showed that,the ultrafine treatment of CFB fly ash can solve the volume stability problem of its product,with the increase of ultrafine CFB fly ash content,the 28 days compressive strength of mortar specimen increased first and then decreased,among different CFB fly ash contents,the highest 28 days compressive strength was achieved when the cement was replaced by 20% CFB fly ash,reaching 48.5 MPa.As compared to the mortar specimen without ultrafine CFB fly ash incorporation,the compressive strength loss of mortar specimen with 20% ultrafine CFB fly ash of cement replacement decreased by 76%after 25 freeze-thaw cycles,and the mass loss decreased by 36% after 48 h weak acid corrosion test.Studies on adaptability of different water reducing agent revealed that the effect of water reducing on mortar specimen with ultrafine CFB fly ash incorporation was naphthalene water reducing agent better than polycarboxylate water reducing agent.The water reduction efficiency could reach about 22% when adding about 1.5% naphthalene water reducing agent.