水泥石吸水吸油体积变形性能及其机理  

Deformation Properties and Mechanism of Hardened Cement Pastes During Water/Oil Immersion

作　　者：杨瑞芳[1] 孔祥明[1] 卢子臣[1] 王其春[2] 曾敏[2] 周仕明[2] 

机构地区：[1]清华大学土木工程系,北京100084 [2]中国石化石油工程技术研究院,北京100101

出　　处：《硅酸盐学报》2017年第2期182-189,共8页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金(U1301241;U1262107)资助项目

摘　　要：研究了聚合物乳液改性水泥石的吸水、吸油规律及其吸水、吸油后的线性膨胀性能,并基于实验结果建立了轴向膨胀应变与饱和体积吸水、吸油率的相关关系。吸水、吸油性能测试结果发现:空白水泥石饱和质量吸水率远大于其饱和吸油率,表明有大量孔径更细的毛细孔并不能被油侵入,这是由于油与水泥石较小的毛细作用导致。轴向膨胀应变测试结果显示,空白水泥石初期大量的吸水并不导致显著的体积膨胀,浸水后期较小的体积吸水率却导致明显的体积膨胀。聚合物改性水泥石的饱和质量吸水率与空白水泥石相当,但由于成膜聚合物对毛细孔的阻塞作用,明显降低了水泥石的质量吸水速率。同时,聚合物膜本身的吸油性导致聚合物改性水泥石的饱和质量吸油率略大于空白水泥石。由于聚合物对水泥石孔隙的细化作用,聚合物改性水泥石的吸水、吸油膨胀性均明显大于空白水泥石。采用吸水、吸油速率公式,通过实验测量水泥基材料的吸水、吸油速率系数,可定量评价水泥基材料的渗透性。所建立的水泥石吸水、吸油轴向线性膨胀率公式可用于实际工程中预测水泥石膨胀量的大小。Water/oil absorption and axial expanding strain of polymer modified hardened cement paste （MHCP） were investigated, and the relationship between the axial expanding strain and the saturated water/oil absorption was analyzed. The results show that the blank hardened cement paste （BHCP） absorbs more water than oil when fully saturated, implying that the finer pores are not filled with oil due to a lower affinity of oil to the capillary wall of BHCP. The massive water absorption at early stage does not lead to a significant volume expansion, while the less water absorption at later stage results in the noticeable volume expansion. For BHCP and MHCP, despite their comparable saturated water absorption, the water absorption speed of MHCP is lower than BHCP due to the blocking effect of the polymer film. Besides the pore volume, the presence of polymer film in MHCP leads to the more oil absorption. The expansion of MHCP upon water/oil absorption is larger than that of BHCP due to the refined pore structure by polymer film in MHCP. The permeability of cementitious materials can be quantitatively evaluated via experiments of water/oil absorption. In addition, the linear expansion of cementitious materials upon water/oil absorption can be quantitatively predicated using the equations established.

关 键 词：水泥石 吸附 体积膨胀 水 油 

分 类 号：TU525[建筑科学—建筑技术科学]