粉砂质泥岩遇水损伤规律及化学改性研究

Damage-law of Silty-mudstone in Water and Chemical Modification

为了研究粉砂质泥岩遇水损伤规律和提高其耐崩解性,利用X射线衍射仪、傅里叶变换红外光谱仪、激光共聚焦显微镜、扫描电镜、润湿角测量仪和电子万能试验机等,表征了试样的成分、微观形貌、润湿角、单轴抗压强度和膨胀率等特征。结果表明：改性前试样表面裂纹的宽度随浸水时间的增加而迅速增大,经过10分钟崩解成碎屑,改性后试样浸水2 d表面无明显变化;改性后试样的润湿角由3.9°增为122.2°;经过改性,试样的膨胀率明显减小,大小仅为改性前的37%~44%;改性后泥岩的单轴抗压强度增加了10%~65%。硅酸盐粘土矿物遇水膨胀是粉砂质泥岩内部产生损伤的主要原因。有机硅改性剂与粉砂质泥岩发生缩聚反应,岩粒表面形成非极性的憎水膜,泥岩的憎水性增强;泥岩内部颗粒间的胶结程度改善,单轴抗压强度明显提高。

To improve the harmful properties of silty-mudstone in geotechnical engineering.By X-ray diffractometer,Fourier transform infrared spectrometer,scanning electron microscope（SEM）,threedimensional laser topography measurement instrument,swell test,contact angle measuring instrument and electronic universal testing machine,the silty-mudstone was characterized to research on the change rules of composition,surface topography,wetting angle,uniaxial compressive strength and swell rate,respectively.More attention was paid to the modification mechanism of organosilicon material.The results show that the width of cracks increase with the soaking times of samples,silty-mudstone can disintegrate in water after 10 min,but the samples that were modified by organosilicon material can not disintegrate after immering in water for 2 d.The contact angle of water on the surface of samples increases from 3.9°to 122.2° after modification.The expansion ration of samples decreases to 37%-44%.Uniaxial compressive strength increases by 10%-65%.Hydrophobic film forms through condensation polymerization active groups of organic silicon material in the surface of sample grains.The cementation condition between grains of silty-mudstone is enhanced by organosilicon material,the uniaxial compressive strength of mudstone is enhanced accordingly.