摘要
弹性模量作为水泥砂浆重要的性能参数和结构设计参数,对于保障构件的服役安全性和可靠性至关重要。为解决水泥砂浆在低温与高温服役条件下的弹性模量准确测量的技术难题,将修正缺口环法与相对法结合(称为修正缺口环相对法),成功测得了硅酸盐水泥砂浆在-70～800℃下的弹性模量,并研究了饱水与干燥砂浆试样的弹性模量随温度变化的演变规律。测试结果表明:由室温降至-70℃,冰的填充与胶粘作用会使得饱水砂浆的弹性模量增加32. 67%,且模量增长速率随着温度的降低逐渐增大;而干燥砂浆的水分含量较低,其弹性模量在降温过程中基本保持不变。由室温升至800℃过程中,由于水化产物的高温脱水分解与微结构劣化,饱水砂浆的弹性模量降低了93. 78%,而干燥砂浆的弹性模降低了83. 51%,且模量衰减速率随着温度的升高而逐渐降低。
As a crucial performance parameter and structural design parameter of the cement mortar,the elastic modulus is of great importance to ensure safety and reliability of the cement-based components in service.Aiming at conquering the technical problem that the elastic modulus of cement mortar under low and high temperature service conditions cannot be measured accurately,an innovative method(named as the relative modified split ring method)combining the modified split ring method and the relative method was employed in this study,the elastic modulus of Portland cement mortar at-70-800℃was successfully measured.Besides,the evolution law of elastic modulus of water-saturated and dry mortar samples as a function of temperature is investigated.The results indicated that there was a 32.67%increase of elastic modulus of water-saturated mortar,in the range from ambient temperature to-70℃,owing to the filling effect and gluing effect of the ice,and the growth rate of modulus increased gradually with the drop of test temperature.While the modulus of the dry piece remained unchanged in the process of cooling,thanks to its low water content.Due to the dehydration and decomposition of the hydration products and the microstructure degradation at high temperature,the elastic modulus of the water-saturated and dry samples declined by 93.78%and 83.51%,respectively,with the increasing temperature from room temperature to 800℃.And the modulus decreasing velocity was gradually reduced with increase of test temperature.
作者
聂光临
包亦望
田远
万德田
NIE Guanglin;BAO Yiwang;TIAN Yuan;WAN Detian(State Key Laboratory of Green Building Materials,China Building Materials Academy Co.,Ltd,Beijing 100024;China Building Material Test&Certification Group Co.,Ltd,Beijing 100024)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2019年第2期251-256,共6页
Materials Reports
基金
国家自然科学基金(51472227)
国家高技术研究发展计划(863计划)(2015AA034204)
国家重点研发计划(2017YFB0310400)~~
关键词
修正缺口环法
相对法
水泥砂浆
弹性模量
低温
高温
modified split ring method
relative method
cement mortar
elastic modulus
low temperature
high temperature
作者简介
聂光临,2018年7月毕业于中国建筑材料科学研究总院,获得材料学博士学位,师从包亦望教授,主要从事材料力学性评价技术的研究,已发表20余篇论文,申请9项专利;包亦望,中国建筑材料科学研究总院教授,中国建材检验认证集团股份有限公司首席科学家,1990年毕业于中国建筑材料科学研究总院,获材料学博士学位。主要从事极端环境条件下无机材料力学性能测试评价新技术的研究。发表SCI论文120余篇,EI论文180余篇;取得五十多项专利,6项创新技术被制订为国际标准;出版专著两部。
