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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。
Based on the experimental results, the relationship between the axial expansion strain and the saturated volumetric water absorption and oil absorption rate was established. The results of water absorption and oil absorption test showed that the saturated water absorption of blank cement was far greater than the saturated oil absorption, indicating that a large number of pores with finer pore size could not be invaded by oil due to the smaller capillary action between oil and cement . Axial expansion strain test results show that a large amount of water absorption of blank cement does not result in significant volume expansion at early stage, but a small volume water absorption at the later stage of immersion leads to significant volume expansion. The saturated mass water absorption of polymer-modified cementite is equivalent to that of blank cement, but due to the blockage effect of the film-forming polymer on the pores, the mass water absorption rate of cement stone is obviously reduced. At the same time, the oil absorption of the polymer film itself resulted in a slightly greater saturated oil absorption rate of the polymer modified cement than that of the blank cement. Due to the refinement effect of polymer on the pores of cement stone, the water absorption and oil absorption expansibility of polymer modified cement stone are obviously larger than that of blank cement stone. Adopting the formula of water absorption and oil absorption rate, the water absorption and oil absorption rate coefficient of cement-based materials can be measured experimentally to quantitatively evaluate the permeability of cement-based materials. The established formula of water absorption and axial expansion of oil absorption cement can be used to predict the amount of expansion of cement stone in the actual project.