仿岩溶碳酸氢钙加固风积沙的试验研究

分别以仿岩溶碳酸氢钙（CFPK）溶液和毛乌素沙地风积沙为固沙材料和加固对象，通过化学试验、力学试验、水理试验以及微观试验，探究二氧化碳压强和反应时间对CFPK溶液浓度的影响，分析CFPK溶液固化沙的工程性能，揭示其加固机理。结果表明：CFPK溶液浓度随着二氧化碳压强的增大而增大，随着反应时间的增加先增大而后保持稳定。呈散粒状的风积沙经过CFPK溶液处理后，其表面形成一层固结层，具有较高的表面强度、较好的抗风蚀性和耐水性。随着CFPK溶液用量的增加，固化沙的表面强度和抗风蚀性能逐渐提高。仿岩溶碳酸氢钙可在沙颗粒间分解形成具有胶结作用和填充作用的碳酸钙，能够有效加固风积沙。

Reinforcement of aeolian sand with calcium bicarbonate formed by pesudo-karstification

Taking the solution of calcium bicarbonate formed by pesudo-karstification (CFPK) as sand solidification material and the aeolian sand in the Mu Us Desert as the reinforcement object, we conducted a series of chemical tests, mechanical tests, hydraulic tests and microscopic tests to investigate the influence of carbon dioxide pressure and reaction time on the concentration of CFPK solution. Then the engineering performance of sand solidification by CFPK solution was analyzed to reveal the reinforcement mechanism of CFPK. The results show that the concentration of CFPK increases with the increase of carbon dioxide pressure, whereas increases first and then stabilizes with the increase of reaction time. After the reinforcement treatment of CFPK solution, a consolidated layer is formed on the surface of the loose aeolian sand, which strengthens the surface strength, wind erosion resistance and water resistance of the aeolian sand. With the increase of the amount of CFPK solution, the surface strength and wind erosion resistance of the solidified sand gradually increases. The CFPK can decompose among the sand particles to form calcium carbonate that act as cementation and filling agent, by which the aeolian sand can be effectively strengthened.