Research On The Properties Of Clay-based Sand-fixing Composite Material

Desertification is a long-term and most serious ecological problem around theworld currently. It is also the focus and difficulty of China’s ecological construction.The deterioration of ecological environment caused by desertification make peopleliving in poverty and even becoming a serious obstacle in their life, which made greatharm to national economic and social sustainable development. Therefore, research onsand-fixation to improve the local environment has important practical significance ofthe national economy development. In this article, the natural clay was used as mainmaterial, mixed with environment-friendly polymer to prepared sand-fixing materials.The properite of the sand-fixing materials was characterized by compressive strength,water resistance, aging resistance, and wind erosion resistance. The optimizationratios from caly, polymer (polyvinyl alcohol, plant straws, carboxymethyl cellulosesodium) was also obtained. From the filed experiments, we can confirm, using thesand-fixing material, the sand fixing method exhibit multifunction properties, such asengineering, chemical, biological sand fixing and good application prospects.The main contents are as follows:1. Using clay (red clay and loess) as the main component, complexed withenvironment-friendly polymer (CMC, PVA), biopolymer(plant straws) as clay basedsand-fixing material. Morphology structure, compressive strength, water resistanceand aging resistance of the clay-based sand-fixing material were studied. Structuralcharacterization shows the sand-fixing materials can decentralized sands tosolid-caking; Compressive strength tests shows that the polymer content of0.1%to2%for sand-fixing agent preferably, most of the compressive strength exceed1Mpa;water resistance and aging resistance test shows that polymer added in the sand-fixinghas good adhesive force, film-forming properties, the solid-caking has little pore, thewater resistance, aging resistance properties of the sandfixing material becomestronger, and the effect lasted.2. Wind tunnel was used to studied solid-caking wind erosion resistance. theexperiments shows with increasing of the sand flow rate, the amount of wind erosionincrease; the sample surface and sand flow slope will impact on amount of winderosion directly, under the same sand flow rate, with the angle increased, the winderosion increase; the wind erosion resistance of different sand stabilization materialdiffer slightly, and it become stronger by adding polymer material. 3. Using natural clay as main material, complexed with environment-friendlypolymer,the clay crust, different forms of clay barrier (hexagonal grid, plum grid,vaulted grid, etc.) were prepared. The experimental results show that the clay barriersto fixed and shunted sand well. The clay barrier can protect growth ofpsammophytes，make its roots against sand erosion, also, the clay barrier can providenutrition for psammophytes. On the same time, the sand-fixing materials has thermalinsulation and water retention properities, it is plays a catalytic role in the recovery ofvegetation in deserts.