CFB灰渣抹灰砂浆的组成设计与性能研究

为了提高抹灰砂浆的强度和体积稳定性,研究了水泥用量和灰渣比(循环硫化床(CFB)飞灰和CFB炉渣的质量比)对CFB灰渣抹灰砂浆2 h稠度损失率、抗压强度和体积稳定性的影响,并采用扫描电子显微镜、X射线能谱仪和X射线衍射仪对砂浆的微观形貌、元素分布和物相组成进行测试表征。结果表明,当水泥用量为5%、8%、12%(质量分数)时,CFB灰渣抹灰砂浆分别达到抹灰砂浆M10、M15、M20的强度等级。当胶凝材料用量一定时,随着水泥用量增大,砂浆2 h稠度损失率减小;当水泥用量一定时,随着灰渣比增大,砂浆2 h稠度损失率增大,膨胀效应减弱。CFB灰渣抹灰砂浆中生成的膨胀性钙矾石有效填充了颗粒之间的孔隙,从而提高砂浆的强度和体积稳定性。

Composition Design and Performance of CFB Fly Ash and CFB Slag Plastering Mortar

In order to improve the strength and volume stability of plastering mortar,the effects of cement content and ash-slag ratio(mass ratio of CFB fly ash to CFB slag)on 2 h consistency loss rate,compressive strength and volume stability of CFB fly ash and CFB slag plastering mortar were studied.The micro morphology,element distribution and phase composition of mortar were characterized by scanning electron microscope,X-ray energy spectrometer and X-ray diffractometer.The results show that when the cement content is 5%,8%and 12%(mass fraction),the strength grade of CFB fly ash and CFB slag plastering mortar reaches M10,M15 and M20,respectively.When the content of cementitious material is constant,the 2 h consistency loss rate of mortar decreases with the increase of cement content.And when the content of cement is constant,the 2 h consistency loss rate of mortar increases and the expansion effect decreases with the increase of ash-slag ratio.Expansive ettringite generated in the CFB fly ash and slag plastering mortar fills the pores between the particles effectively,so as to improve the strength and volume stability of mortar.