丙苯乳液改性聚合物水泥力学性能和内部结构研究

The Mechanical Properties and Internal Structure for SAE PolymerModified Cement

本文研究了丙苯乳液 (SAE)改性聚合物水泥 (PMC)力学性能和内部结构。当聚合物用量与水泥用量之比(P/C)由 0增加到 2 5 %时 ,PMC的抗压强度几乎下降了 5 0 % ,延性增大了近 5倍。聚合物与水泥的化学反应增加了PMC的强度。当P/C≥ 10 %时 ,压应变在约 90 %的最大应力处迅速增加 ,并在最大应力处表现出塑性流动。本文提出了在不同P/C阶段PMC的内部结构模型。在这一模型中 ,随着P/C增加 ,聚合物相从作为水泥基相中的分散相到与水泥相共同形成网络 ,直到最后成为水泥相分散在其中的基相。在本试验范围内 ,基相转换的临界点P/C分别是 5 %和 2 0 %。PMC的压应力—应变全曲线显示在应力较小时聚合物延迟了裂缝扩展 。

The mechanical properties and internal structure of styrene-acrylic ester (SAE) polymer modified cement (PMC) have been studies. For PMC, with increase in the radio of polymer to cement(p/c) from 0～25%, it has been found that the strength in compression decreases by almost 50%, the deformation increases and the ductility increases by 500%. The reaction between polymer and cement increases the strength of PMC. The strains in compression near 90% peak stress increase rapidly and show plastic flow at the peak stress when p/c is not less than 10%. An internal structural model for PMC at different p/c is proposed in this paper. In this model, the polymer phase varies from dispersions in cement to forming a network with the cement phase and finally, to becoming a matrix that the cement phase disperses in it. The critical p/c is 5% and 20% respectively. A complete compression stress-strain curves of PMC has been studied. It is found that the polymer phase retards the propagation of cracks produced in PMC at low stress and carries the load after cracks spread throughout the section of the specimen. 〔