有机质含量对磷酸镁水泥固化土性质的影响研究

STUDY ON THE EFFECT OF ORGANIC CONTENT ON PROPERTIES OF MAGNESIUM PHOSPHATE CEMENT SOLIDIFIED SOIL

许多重要的软土工程譬如基坑、路基工程在破坏后需要快速修复,磷酸镁水泥的出现很好地满足了这一现代建设的要求,但不同地区软土的有机质含量不同,而有机质的含量对固化土的性质有着重要影响。为了研究磷酸镁水泥加固不同有机质含量软土的加固规律,本文通过向烘干后的软土中添加腐殖酸,人为制备不同有机质含量的土样,并取相同条件下PO水泥加固软土作对比,通过相关力学试验得到以下规律:两种水泥在加固不同含量有机质软土的过程中,加固效果都会随着有机质含量的升高而逐渐降低;磷酸镁水泥在快速修复和凝结方面明显优于PO水泥,但磷酸镁水泥中长期加固有机质软土的效果却不及PO水泥。同时利用SEM试验对得到的规律进行了解释并分析其微结构演化特征。该研究成果独到地分析了有机质含量变化对磷酸镁水泥加固效果的影响,证明了磷酸镁水泥可以应用于软土的抢修工程建设中,对加固软土工程具有指导和借鉴意义。

Many important soft soil projects need to be repaired quickly after failure,such as foundation pits and subgrade engineering.The appearance of magnesium phosphate cement satisfies the requirements of modern construction.However,the difference of the organic content of soft soil in different regions has an important influence on the properties of the solidified soil.We prepare soil samples with different organic contents by adding humic acid to the soft soil and study the reinforcement of soft soil with different organic contents by magnesium phosphate cement,contrast with the reinforced soft soil of PO cement under the same conditions.Finally,the following laws are obtained through the relevant mechanical tests:in the process of strengthening different organic contents of soft soil,the reinforcement effect can gradually decrease with the increase of organic content.Magnesium phosphate cement is obviously superior in rapid repair and condensation than PO cement.But long-term reinforcement effect of the magnesium phosphate cement in soft soil is not as good as that of PO cement.At the same time,SEM test is used to explain the obtained rules and analyze the microstructure evolution characteristics.Magnesium phosphate cement can be applied to the construction of soft soil repair projects.The research results uniquely analyze the influence of organic content change on the strengthening effect of magnesium phosphate cement,which has guiding and reference significance for reinforcing soft soil projects.