Influence of different loading rates on the mechanics and failure characteristics of high-water-content material

ABSTRACT

In order to study the effects of loading rates on the strength and failure of high-water-content material, the loading rates of 0.1, 0.5, 1, 2 and 5 mm/min were selected to conduct uniaxial tests on standard specimens with water cement ratios of 2:1, 4:1 and 6:1 by curing for 1, 3, 7 and 28 days, respectively. The mechanics and failure characteristics of high-water-content material in different loading rates and curing ages were obtained. The results show that the elastic modulus and peak strength of high-water-content material are in direct proportion to the loading rates and curing ages. However, the mass loss rate is inversely proportional to the loading rates and curing ages. When the loading rate is low, high-water-content materials mainly have a circumferential tensile failure. On the contrary, shear failure mainly occurs and more debris is produced. The effect mechanisms and the mutual feedback relationship between the loading rates and the mechanics and failure characteristics of high-water-content material are revealed. The results provide a reference for the selection of high-water-content material in the filling of underground coal mines.

KEYWORDS:

• High-water-content material
• failure characteristic
• loading rate
• curing age
• mechanical property

Disclosure statement

The authors declare that they have no conflicts of interest.

Additional information

Funding

This work was financially supported by the National Natural Science Foundation of China [52074296, 52004286], the China Postdoctoral Science Foundation [2020T130701, 2019M650895], the Fundamental Research Funds for the Central Universities [2020YJSNY06], and the Yue Qi Young Scholar Project, China University of Mining & Technology, Beijing [800015Z1104].