中山大学学报（自然科学版）（中英文）2024，Vol.63Issue(4)：19-28,10.DOI:10.13471/j.cnki.acta.snus.2023D035
海南北部玄武岩实时温度单轴拉-压强度试验研究
Experimental study on real-time temperature uniaxial tensile-compression strength of basalts from the northern Hainan province
摘要
Abstract
The north part of Hainan Province has widely distributed,abundant basaltic rocks providing a great potential for carbon geological sequestration via mineralization.Engineering practice of carbon sequestration in subsurface basalt requests to understanding of the mechanical properties of basalt at real-time temperature.In this study,Brazilian splitting and uniaxial compression experiments were performed on late Cenozoic basalt samples(mainly minerals including Augite,Al-rich,and Anorthite)collected from northern Hainan Province under real-time temperature conditions of 25-250℃,to investigate the effects of temperature on the strength and failure characteristics of the basalt samples.The Brazilian splitting tests show that the tensile strength of the basalt samples reduced from～13 MPa at room temperature to～8 MPa at 50℃,and finally to～7 MPa at 250℃,accompanied by a dominant fracture surface.The uniaxial compression experiments determine the Young's modulus and Poisson's ratio of 31.0-175.3 GPa and 0.13-0.48,respectively,having the maximum values at temperatures of 100-150℃.The compressive strength of 77.5-159.5 MPa decreases slightly with temperature but is associated with larger discreteness.The basalt samples upon uniaxial compression exhibited shear failure along a single plane at temperatures of 25-100℃,while shear failures along multi-planes at temperatures of 150-250℃.This may be attributed to the increase of the proportion of tensile microcracks upon temperature rise during the microcracking process.Combining the results from both experiments,the tensile strength reduction and the scattered uniaxial compression mechanical parameters observed at temperatures of 25-250℃are likely dominated by the thermally activated rate process,rather than the thermal damage mechanism.From a perspective of temperature-dependent mechanical properties of the collected basalt samples,this study implies that deep burial depth(higher temperature)favors the carbonation reaction of basalt and CO2,as the reduction of tensile strength may accelerate the fracturing process to enhance the reactive surface between basalt and CO2-rich fluids.Nevertheless,complex deformation and failure mechanisms caused by temperature during in-situ subsurface carbon sequestration in basalt also need serious considerations in future studies.关键词
海南玄武岩/CO2地质封存/破裂模式/巴西劈裂/抗拉强度Key words
Hainan basalt/carbon geological sequestration/failure modes/Brazilian test/tensile strength分类
建筑与水利引用本文复制引用
刘锐鸿,刘金锋..海南北部玄武岩实时温度单轴拉-压强度试验研究[J].中山大学学报（自然科学版）（中英文）,2024,63(4):19-28,10.基金项目
广东省基础与应用基础研究基金(2021A1515012202) （2021A1515012202）
