首页期刊信息编委及顾问期刊发行联系方式使用帮助留言板ENGLISH
位置:首页 >> 正文
应变率对硬化水泥净浆微观力学性能及徐变行为的影响
作者:  梁思明   
单位:清华大学土木工程系 土木工程安全与耐久教育部重点实验室 北京 100084 
关键词:硬化水泥净浆 力学性能 微观徐变 连续刚度测试 应变率 
分类号:TB321
出版年,卷(期):页码:2017,45(11):0-0
DOI:10.14062/j.issn.0454-5648.2017.11.06
摘要:

 采用连续刚度测试研究应变率对硬化水泥净浆微观力学性能及徐变行为的影响,结合扫描电镜技术分析水泥净浆的

微观结构对连续刚度测试结果的影响。结果表明:通过30 μm 压入深度的连续刚度测试可以得到水泥净浆均匀的力学性能,
当压入深度(荷载)大于临界最小深度(荷载)时,测试得到的弹性模量和压痕硬度基本保持不变,反映了水泥净浆均匀的力学性
质;在0.01 s–1~0.50 s–1 应变率范围内,应变率变化对硬化水泥净浆弹性模量的影响可忽略不计,但压痕硬度随着应变率的增
大而增大,且二者具有幂型函数关系;应变率影响持载阶段的接触徐变函数,应变率越大,持载阶段的接触徐变函数越大,
这与应变率越大时加载阶段的徐变发展越不充分有关。为了准确测试水泥净浆的微观徐变,需尽可能减小加载阶段的用时。

 The strain rate effect on the elastic modulus, indentation hardness, and micro creep of hardened cement paste was

investigated via continuous stiffness measurement. The microstructure of the indentation zone was determined by scanning electron
microscopy. The effect of microstructure on the mechanical and creep properties was analyzed. The results show that the
homogeneous mechanical properties of cement pastes can be measured via continuous stiffness measurement with a maximum depth
of 30 μm. When the indentation depth (force) is greater than the critical minimum depth (force), the measured elastic modulus and
indentation hardness will remain nearly a constant, reflecting the homogeneous mechanical properties of cement pastes. Within the
strain rates ranging from 0.01 s–1 to 0.50 s–1, the strain rate has a negligible effect on the elastic modulus. However, the indentation
hardness increases with increasing the strain rate, and their relationship can be well expressed by an empirical power law equation.
Strain rate also affects the contact creep function during the holding stage. The greater the strain rate, the greater the contact creep
function is, which is due to the fact that the creep will develop less during the loading stage at a greater strain rate. It is thus necessary
to minimize the loading time to ensure correct measurement of the creep property.
基金项目:
国家自然科学基金项目(51578316,51778331)
作者简介:
魏 亚(1976—),女,博士,博士研究生导师,副教授
参考文献:
[1] Harsh S, Shen Z, Darwin D. Strain-rate sensitive behavior of cement paste and mortar in compression[J]. ACI Mater J, 1990, 87(5): 508–516.
[2] Pan H H, Weng G J. Study on strain-rate sensitivity of cementitious composites[J]. J Eng Mech, 2010, 136(9): 1076–1082.
[3] 肖诗云, 张剑. 不同应变率下混凝土受压损伤试验研究[J]. 土木工程学报, 2010, 43(3): 40–45.
XIAO Shiyun, ZHANG Jian. China Civ Eng J (in Chinese), 2010, 43(3): 40–45.
[4] The Euro-International Committee for Concrete (CEB). CEB-FIP model code 1990[S]. Lausanne: Thomas Telford Ltd, 1993.
[5] 王长青, 肖建庄, 孙振平. 应变率效应对再生混凝土动态力学性能的影响[J]. 同济大学学报: 自然科学版, 2016, 44(8): 1173–1181.
WANG Changqing, XIAO Jianzhuang, SUN Zhenping. J Tongji Univ: Nat Sci (in Chinese), 2016, 44(8): 1173–1181.
[6] ACKER P. Micromechanical analysis of creep and shrinkage mechanisms[A]. Creep, Shrinkage and Durability Mechanics of Concrete and other quasi-brittle Materials[C]. Cambridge, MA, 2001: 15–25.
[7] 赵素晶, 孙伟. 纳米压痕在水泥基材料中的应用与研究进展[J]. 硅酸盐学报, 2011, 39(1): 164–176.
ZHAO Sujing, SUN Wei. J Chin Ceram Soc, 2011, 39(1): 164–176.
[8] VANDAMME M, ULM F J. Nanoindentation investigation of creep properties of calcium silicate hydrates[J]. Cem Concr Res, 2013, 52: 38–52.
[9] 梁思明, 魏亚. 硬化水泥净浆微观结构对微观徐变及力学性能的影响[J]. 硅酸盐学报, 2016, 44(2): 181–188.
LIANG Siming, WEI Ya. J Chin Ceram Soc, 2016, 44(2): 181–188.
[10] LI X, BHUSHAN B. A review of nanoindentation continuous stiffness measurement technique and its applications[J]. Mater Charact, 2002, 48(1): 11–36.
[11] HAY J, AGEE P, HERBERT E. Continuous stiffness measurement during instrumented indentation testing[J]. Experim Techniques, 2010, 34(3): 86–94.
[12] SNEDDON I N. The relation between load and penetration in the axisymmetric Boussinesq problem for a punch of arbitrary profile[J]. Int J Eng Sci, 1965, 3(1): 47–57.
[13] OLIVER W C, PHARR G M. An improved technique for determining hardness and elastic modulus using load and displacement sensing indentation experiments[J]. J Mater Res, 1992, 7(06): 1564–1583.
[14] 王培铭, 丰曙霞, 刘贤萍. 背散射电子图像分析在水泥基材料微观结构研究中的应用[J]. 硅酸盐学报, 2011, 39(10): 92–98.
WANG Peiming, FENG Shuxia, LIU Xianping. J Chin Ceram Soc, 2011, 39(10): 92–98.
[15] 张倩倩, 魏亚. 基于背散射电子图像的矿渣-水泥复合体系反应程度定量分析[J]. 硅酸盐学报, 2015, 43(5): 563–569.
ZHANG Qianqian, WEI Ya. J Chin Ceram Soc, 2015, 43(5): 563–569.
[16] LARSSON P L, GIANNAKOPOULOS A E, SÖDERLUND E, et al. Analysis of Berkovich indentation[J]. Int J Solids Struct, 1996, 33(2): 221–248.
[17] GB/T 50081—2016普通混凝土力学性能测试方法标准[S]. 北京: 中国建筑工业出版社, 2016.
GB/T 50081—2016 Standard for test method of mechanical properties on ordinary concrete[S]. Beijing: China Architecture & Building Press, 2016.
[18] VANDAMME M, TWEEDIE C. A, CONSTANTINIDES G, et al. Quantifying plasticity-independent creep compliance and relaxation of visco-elasto-plastic materials under contact loading[J]. J Mater Res, 2012, 27(1): 302–312.
[19] ZHANG Qing, LE R R, VANDAMME M, et al. Long-term creep properties of cementitious materials: Comparing microindentation testing with macroscopic uniaxial compressive testing[J]. Cem Concr Res, 2014, 58: 89–98.
服务与反馈:
文章下载】【加入收藏
中国硅酸盐学会《硅酸盐学报》编辑室
京ICP备10016537号-2
京公网安备 11010802024188号
地址:北京市海淀区三里河路11号    邮政编码:100831
电话:010-57811253  57811254    
E-mail:jccs@ceramsoc.com