以新生代煤系地层中的泥岩作为研究对象,对泥岩进行有机硅材料改性试验。采用静态水接触角法、液氮等温吸附、自由膨胀试验、扫描电镜能谱分析以及常规岩石力学强度试验等物理化学测试手段对比分析泥岩改性前后疏水性、孔裂隙、胀缩性、微结构及物理力学特征等物性变化规律,并分析有机硅改性泥岩的改性机制。结果表明:(1)有机硅材料可有效改变泥岩的表面结构与性质,岩样表面水滴润湿角由8.51°增至113.34°,由亲水性变为憎水性。(2)改性后孔裂隙形态变化不大,但总量明显减小,氮气吸附量由26.488 2 cm3/g减少至9.477 3 cm3/g,BET比表面积由13.029 8 m2/g减少至2.856 4 m2/g,孔隙最大孔径由150 nm左右减小至110 nm左右。(3)岩样自由膨胀率由3.54%减少至0.51%。(4)改性后岩样化学元素组成比例发生了较大变化,碳元素的大量增加和硫元素的出现表明改性材料已渗入岩样内部。(5)改性后岩样的强度显著增加,其中单轴抗压强度由9.3 MPa增至26.05MPa,抗拉强度由1.69 MPa增至3.22 MPa。
Argillaceous shale is a very common rock that when in contact with water can show considerable volume change and breakdown.The behaviour of argillaceous shale is frequently encountered in geotechnical engineering and has a considerable influence on infrastructure stability.This is particularly important in the present work,which focuses on improving the harmful properties of argillaceous shale.The samples studied are of Permian Age argillaceous shale from the Shandong province,China,modified tests by organic silicon material were carried out.The change rules of surface hydrophobic property,porosity and fracture,swelling and shrinkage,microstructure and physico-mechanical properties of argillaceous rock were comparative researched by static water contact angle method,nitrogen adsorption isotherm method,free swell test,SEM-EDS analysis and conventional rock mechanics strength test respectively;and modification mechanism of organic silicon material modified argillaceous rock is analyzed.Results show that:(1) The surface texture and characters of argillaceous rock changed dramatically for modified,the contact angle of water drops on the rock sample surface increases from 8.51°to 113.34°,surface character turns from hydrophilic to hydrophobic.(2) The shape of porosity and fracture of argillaceous rock changed unremarkable,and the total decreased obviously for modified,nitrogen adsorption decreased from 26.488 2 cm3/g to 9.477 3 cm3/g,BET surface area decreased from 13.029 8 m2/g to 2.856 4 m2/g,and the maximum pore size decreased from 150 nm to 110 nm or so.(3) Free expansion ratio of argillaceous rock decreased from 3.54% to 0.51%.(4) The chemical element composition of argillaceous rock altered largely,and carbon element increased and sulfur element found for modified indicated organic silicon material infiltrated rock inward.(5) Strength of rock increased obviously for modified,uniaxial compressive strength increased from 9.3 MPa to 26.05 MPa;tensile strength increased from 1.69 MPa to 3.22