摘要
为提升寒冷地区建筑结构的实时损伤监测效果,研究了硫酸盐-冻融循环作用下采用短切碳纤维与铁尾矿作为导电材料制备的自感应水泥砂浆的耐久与压敏性能。利用质量损失、相对动弹性模量及抗压强度损失为依据探讨耐久性能变化规律,以电阻率变化率-压应力的相关关系反映硫酸盐-冻融循环作用下压敏性能发展规律并解释其导电机理,并采用平均应力敏感系数评价硫酸盐-冻融循环作用下压敏性能稳定性。结果表明,碳纤维体积掺量为0.4%、铁尾矿替代率为30%(质量分数)组合掺入水泥砂浆时,其耐久性能与压敏性能均达到较高水平,但硫酸盐-冻融循环造成的孔洞与裂缝会导致铁尾矿碳纤维水泥砂浆电阻率变化率-压应力呈一阶指数衰减关系,可采用Plane模型来反映平均应力敏感系数衰减程度与冻融循环次数、铁尾矿替代率之间良好的相关关系。
To improve the real-time damage monitoring effect of building structures in cold regions,the durability and piezoresistivity of self-sensing cement mortar prepared by using chopped carbon fiber and iron tailings as conductive materials under the sulfate freeze-thaw cycles were studied.Based on the mass loss,relative dynamic elastic modulus and compressive strength loss,the change law of durability performance was studied,the correlation between fractional change in resistivity and compressive stress was used to reflect the development law of piezoresistivity under the sulfate freeze-thaw cycles and the conduction mechanism was explained,the average stress sensitivity coefficient was used to evaluate the stability of piezoresistivity under the sulfate freeze-thaw cycles.The results show that cement mortar combined with 0.4% volume of carbon fiber and 30%(mass fraction) replacement rate of iron tailings reach a better level of durability and piezoresistivity.The fractional change in resistivity-compressive stress shows a first-order exponential decay relationship due to the holes and cracks caused by sulfate freeze-thaw cycles.The Plane model can be used to reflect the good correlation among the attenuation degree of average stress sensitivity coefficient and the number of freeze-thaw cycles and the replacement rate of iron tailings.
作者
李一凡
王社良
徐晋
白娇娇
全晓旖
徐卫锋
LI Yifan;WANG Sheliang;XU Jin;BAI Jiaojiao;QUAN Xiaoyi;XU Weifeng(School of Civil Engineering,Xi’an University of Architecture and Technology,Xi’an 710055,China;School of Civil Engineering,Xijing University,Xi’an 710123,China)
出处
《硅酸盐通报》
CAS
北大核心
2022年第3期777-786,共10页
Bulletin of the Chinese Ceramic Society
基金
国家自然科学基金面上项目(51678480)
陕西省重点研发计划(2021SF-521)。
