基于填充胶结效应的千枚岩土-红粘土-固化剂复合改良机制研究

江西省千枚岩土广泛分布，该种土难压实且膨胀率大，常作为弃方处理。掺入红黏土后可以把接触型排列转化成基底型胶结，但水稳性较差。本课题提出以红黏土作为充填和弱胶结材料，以固化剂作为强胶结材料对千枚岩土进行复合改良，形成接触型排列-孔隙型胶结-基底型胶结的转换和胶结强度从弱到强的转换，实现较好的初期承载性能和长期承载性能。项目系统研究固化剂与黏粒反应产物对复合改良填料工程性质的影响。首先利用XRD、SEM等测定复合改良填料矿物成分特征与微观结构；然后通过不同组合改良方案的宏观力学性能、变形性能、抗渗性能等试验，获得工程性质指标随接触型排列向孔隙型和基底型胶结转化中的变化规律；分析影响胶结类型与胶结强度的关键因素，阐明复合改良土强度形成与多物相协同作用机制，形成千枚岩土-红黏土-固化剂复合改良填料理论。研究成果为复合改良填料提供新思路，对两种特殊土的广泛使用和减小弃方有重要意义。

Phyllite soil is widely distributed in Jiangxi Province, and it is often treated as abandonment due to its special engineering properties. After adding red clay, the contact-arrangement can be transformed into base-cementation, but the water stability of the mixed filler is poor. In this subject, red clay is used as filling and weak-cementation material, and solidifying agent is used as strong-cementation material to improve phyllite soil, which can form the conversion among contact-arrangement, pore-cementation and basement-cementation, and also form the conversion between weak-cementation and strong-cementation, so as to achieve better initial and long-term bearing performance. The effects of the reaction products of solidifying agent and clay particles on the engineering properties of the composite modified filler were systematically studied. Firstly，Mineral compositions and the microstructure of the composite improved filler was characterized by XRD, SEM tests. Secondly, based on the tests of macro-mechanical properties, deformation properties and impermeability of different combination improvement schemes, the variety of engineering properties in the transformation from contact-arrangement to pore-cementation and base-cementation is obtained. Thirdly, according the theoretical analysis, some achievements will be obtained, such as key factors affecting the cementation type and the cementation strength, the mechanism of the strength formation, synergistic action of the multi-material and theory of phyllite soil, red clay, and solidified agent composite improved filler. The research results provide a new idea for composite improved filler, which has great significance for the widespread use of phyllite soil, red clay and the reduction of abandonment.