Dynamic splitting tensile test of granite under freeze-thaw weathering. Issue 140 (January 2021)

• Record Type: Journal Article
• Authors: Liu, Chuanju; Wang, Daguo; Wang, Zhixiu; Ke, Bo; Li, Ping; Yu, Songtao
• Is Part Of: Soil dynamics and earthquake engineering. Issue 140(2021)
• Publication Date: 2021-01
• Subjects: Freeze-thaw cycle -- NMR -- T2 spectrum distribution -- SHPB -- Mechanical integrity; Soil dynamics -- Periodicals; Earthquake engineering -- Periodicals; Sols -- Dynamique -- Périodiques; Génie parasismique -- Périodiques; 624.176205
• DOI: 10.1016/j.soildyn.2020.106411
• Languages: English
• ISSNs: 0267-7261

Abstract

Abstract: To study the influence of freeze-thaw weathering on dynamic tensile properties and damage mechanism of rock material, the porosity and T2 spectrum distribution of rock samples underwent different freeze-thaw cycles were obtained by nuclear magnetic resonance (NMR), and the variation of micropores and macropore that caused by freeze-thaw cycles were calculated by T2 spectrum and then analyzed. In addition, the dynamic splitting tensile test was carried out on rock samples by using split Hopkins pressure bar (SHPB), and dynamic tensile peak strength, Young's modulus and peak strain were gained and analyzed. Dynamic tensile strength degradation prediction model was established to predict the damage of rock caused by freeze-thaw weathering. Results show that the porosity of the rock sample increases with freeze-thaw cycles increase, the freeze-thaw damage on rock microstructure is mainly caused by the expansion of micropores into macropores, while the initiation of micropores is the secondary reason. With freeze-thaw cycles increasing, the peak strain increases, the dynamic Young's modulus decreases. In addition, the effect of freeze-thaw weathering deteriorates the rock's anti-deformation ability and durability. Highlights: Dynamic mechanical property of freeze-thaw weathering treated Granite was test on SHPB system. Microstructure of Granite sample under different freeze-thaw cycles was test by NMR and then analyzed. Dynamic tensile strength decay model was then established to predict the damage of rock caused by freeze-thaw weathering. When freeze-thaw cycle reaches 204, the mechanical parameters will decay to half of the initial value.