砒砂岩体溃散机理及砒砂岩改性建筑材料研究

The breakup characteristics of Pisha Sandstone under the influence of water caused the serious soil erosion in Inner Mongolia ordos area.In order to effectively control the soil and water loss and promote the vegetation recovery in local area, the study will analyze the difference and connection between the breakuo mechanism of different Pisha Sandstone. In this project, the Pisha Sandstone was treat as a valuble resource from a new point of view, and a new building material with environmentally friendly, economy, good durability and a reliable strength. The present project plans to adopt the combination of experimental study and theoretical analysis to conduct a deep and systematic study on such scientific problems as the physical model and breakup mechanism of Pisha Sandstone. Based on the comprehensive analysis of mineral compositions, structures, geotechnical properties and breakup test of Pisha Sandstone, derive the key parameters on properties and mathematical model of strength of Pisha Sandstone. This project will activate Pisha Sandstone by high temperature calcination, mechanical grinding and adding active silica alumina. By the hydrothermal reaction (with different temperature and pH) experimental research, to reveal the mineral gel transition conditions and rules, find out modification methods of Pisha Sandstone, and develop the Pisha Sandstone modified building materials with compressive strength up to 60MPa, softening coefficient is 0.9, drying shrinkage and durability of meet the requirements.

砒砂岩体遇水溃散特性造成了内蒙古砒砂岩地区严重的水土流失。为了有效的治理水土流失和促进植被恢复，需要明确不同砒砂岩溃散机理的区别和联系。本项目从新的角度认识砒砂岩，拟将砒砂岩研制成一种环保、经济、具有较好力学性能和耐久性能的建筑砂浆材料。拟采用试验研究和理论分析相结合的手段，对砒砂岩的物理模型和溃散机理等问题进行深入系统的研究。通过对不同砒砂岩的矿物组成、结构组成、土工性能和遇水溃散试验的综合分析，推求影响砒砂岩性能的关键参数和强度数学模型。通过高温煅烧、机械粉磨及添加活性硅铝，提高砒砂岩的矿物活性。对砒砂岩进行水热反应（不同的温度和酸碱度）的试验研究，明确砒砂岩中溃散源和填充物等矿物发生胶凝化转变的条件和规律，找到砒砂岩建筑材料化的改性方法，制备出强度达60MPa、软化系数达到0.9、干缩及耐久性满足要求的砒砂岩改性建筑砂浆。

砒砂岩遇水溃散的性质导致了内蒙古砒砂岩地区严重的水土流失。对砒砂岩遇水溃散机理研究能够为当地砒砂岩的治理提供理论基础。而砒砂岩改性建筑材料的研究能够实现砒砂岩的资源化利用。本项目通过对砒砂岩进行物理化学分析和溃散试验的研究，揭示了砒砂岩的遇水溃散机理，研制了砒砂岩改性建筑材料。主要研究内容和结论如下所示：.（1）通过对砒砂岩进行结构组成、矿物组成以及矿物特性分析，明确了砒砂岩是由颗粒支撑物和膨胀粘土及游离氧化物等胶结物构成的，并在此基础上建立起砒砂岩的三元结构物理模型。.（2）通过砒砂岩中矿物基本性能及溃散特性的研究结合砒砂岩的三元结构物理模型，弄清了砒砂岩溃散的根本原因在于自身胶结状态差和含有膨胀粘土矿物（胶结力不足以约束膨胀作用），并提出了砒砂岩遇水溃散物理模型。.（3）结合复合材料强度理论及土的强度理论推导出砒砂岩强度的数学模型，为砒砂岩改性和治理提供理论基础。.（4）采用碱激发技术并结合活化技术，研制出了28d抗压强度达60MPa以上、软化系数达到0.9以上、干缩及耐久性能（抗冻性能）良好的砒砂岩改性建筑材料。