Static and Fatigue Tests on Cementitious Cantilever Beams Using Nanoindenter
Static and Fatigue Tests on Cementitious Cantilever Beams Using Nanoindenter
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DOI：
10.3390/mi9120630
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发表时间：
2018-12-01
期刊：
影响因子：
3.4
通讯作者：
van Breugel, Klaas
中科院分区：
文献类型：
--
作者：
Gan, Yidong;Zhang, Hongzhi;van Breugel, Klaas
水泥净浆是混凝土的主要结合组分，其基本性质对了解混凝土的断裂行为和老化过程具有重要意义。本论文的一个主要目的是利用纳米压痕仪对水泥浆体的微观力学性能进行表征。此外，本文还从微米级对水泥浆体的疲劳行为进行了初步研究。对不同水灰比的水泥净浆制成的微型悬臂梁进行了静载和循环加载试验。根据测得的荷载-位移曲线确定了水泥浆体的细观力学性能。通过残余位移、强度和弹性模数来评价疲劳损伤的演化过程。结果表明，本文所开发的测试方法能够产生可靠的水泥净浆微观力学性能。此外，在50%~70%的外加应力水平下，悬臂梁在1000次加载循环中几乎没有损伤。这项工作对多尺度研究混凝土的疲劳性能具有一定的参考价值。
Cement paste is the main binding component in concrete and thus its fundamental properties are of great significance for understanding the fracture behaviour as well as the ageing process of concrete. One major aim of this paper is to characterize the micromechanical properties of cement paste with the aid of a nanoindenter. Besides, this paper also presents a preliminary study on the fatigue behaviour of cement paste at the micrometer level. Miniaturized cantilever beams made of cement paste with different water/cement ratios were statically and cyclically loaded. The micromechanical properties of cement paste were determined based on the measured load-displacement curves. The evolution of fatigue damage was evaluated in terms of the residual displacement, strength, and elastic modulus. The results show that the developed test procedure in this work is able to produce reliable micromechanical properties of cement paste. In addition, little damage was observed in the cantilever beams under the applied stress level of 50% to 70% for 1000 loading cycles. This work may shed some light on studying the fatigue behaviour of concrete in a multiscale manner.