摘要
探讨了纤维增强MgO/SiO2水泥的水化机理,重点研究了MgO/SiO2混合比例对该体系水化反应过程的影响。通过抗拉/抗弯强度等测试,研究了MgO/SiO2混合比例与老化时间对材料力学性能的影响,确定了材料性能随MgO/SiO2混合比例的变化规律,获得了最优配方;利用SEM、FT-IR等对MgO/SiO2复合材料水合产物的形貌和组成进行了表征;采用pH值和离子浓度表征,研究了MgO/SiO2水泥的水化过程。结果表明,MgO/SiO2混合体系的水化产物为Mg(OH)2和水化硅酸镁凝胶,MgO/SiO2水泥的力学性能受Mg(OH)2与水化硅酸镁凝胶共同作用的影响,60%MgO-40%SiO2混合比为水泥复合材料的最优配方;加入木质纤维素纤维的60%MgO^40%SiO2试件,第1 d老化时的抗弯强度约为9.2 MPa,相较于普通水泥的7.3 MPa,增长达26%,且经过10 d的加速老化,其抗弯强度仍比普通水泥高。可知在MgO/SiO2中加入木质纤维素纤维可显著增强MgO/SiO2水泥的抗弯强度,改善其力学性能。
The hydration mechanism of fiber-reinforced MgO/SiO2 cement was discussed,and the effect of MgO/SiO2 mixture ratio on the hydration process of the system was studied.The influence of MgO/SiO2 mixing ratio and aging time on the mechanical properties of the material was studied through the tensile/bending strength test.The change rule of the material properties with the MgO/SiO2 mixing ratio was determined and the optimal formula was obtained.The morphology and composition of hydration products of MgO/SiO2 composite were characterized by SEM and FT-IR.The hydration process of MgO/SiO2 cement was studied by pH value and ion concentration characterization.The results showed that the hydration products of the MgO/SiO2 mixed system were Mg(OH)2 and hydrated magnesium silicate gel.The mechanical properties of MgO/SiO2 cement were affected by the interaction of Mg(OH)2 and magnesium silicate hydrate.The 60%MgO-40%SiO2 mixing ratio was the best formulation of the cement composite material.The flexural strength of the 60%MgO-40%SiO2 sample added with lignocellulose fiber was about 9.2 MPa on the first day of aging,which was 26%higher than that of the ordinary cement(7.3 MPa),and the flexural strength was still higher than that of the ordinary cement after 10 days of accelerated aging.It could be seen that the addition of lignocellulosic fiber to MgO/SiO2 could significantly enhance the flexural strength and improve the mechanical properties of MgO/SiO2 cement.
作者
李林安
戚佳颖
林泽辉
杨启航
李传崴
王志勇
张庆
LI Linan;QI Jiaying;LIN Zehui;YANG Qihang;LI Chuanwei;WANG Zhiyong;ZHANG Qing(Department of Mechanics, Tianjin Univerity, Tianjin 300350, China;North China Municipal Engineering Design & Research Institute Co., Ltd, Tianjin 300074, China)
出处
《功能材料》
EI
CAS
CSCD
北大核心
2020年第11期11110-11115,共6页
Journal of Functional Materials
