The Formation Conditionof AFm In Stabilized Chlorine Saline Soil And Effect On The Structure And Properties Of Stabilized Soil

Saline soil is of poor quality for the project，stabilizing saline soil using stabilizeris an important way. The existing stabilizer is not apply to saline soil and thecondition of the formation process and stability of hydration products such as AFmand AFt in the stabilized saline soil has not been systematically studied.Based on the simulation of the common type and concentration of salt in thesaline soil, the condition of the formation and stability of expansive hydration wasstudied, and the test for the simulation of artificial stabilized saline soil with theutilization of research results was carried out at the same time. Specific studies are asfollows: based on plusing different ion species and different molar ratio of Cl^-, SO₄^2-,CO₃^2-, change PH as well, mainly by the means of liquid chemical titration analysisand the X-Ray diffraction semi-quantitative analysis, the existence and stabilityconditions of the AFm-like hydration product of the calcined product3CaO-Al₂O₃（P）and the effect of different ion on the hydration product were studied; the effect of theexpansive component, cementitious component, the alkaline component on thestrength and the type of hydration product and morphology of artificial stabilizedsaline soil were also further explored. The key findings are:The14d generate product of P+H₂O system is mainly C3AH6and the reactionactivity of the worst is C12A7. The calcium hydroxide in solution is oversaturated.The hydration product of system P+CaCl₂+H₂O is calcium aluminate chloridehydration, whose reaction has been basically completed in14d. The generated amountof Friedel’s salt increased with the age increasing. The relationship between chlorideion reaction and the age is: y=12.59ln （x）-12.13. While the NaCl quality ratio of thetotal mass of the system changes within0.5%³.5%, the greater the dosage is, thestronger of binding capacity of Cl^-become.Changing the PH of P+CaCl₂+H₂O system to11with hydrochloric acid, thehydration of the system will be promoted; PH range of stable Friedel’s Salt should be>9.7When the sulfate proportion of P+CaCl₂+SO₄^2-+H₂O system accounts for1.5%².5%, Ca8Al4O12Cl₂SO4·24H₂O will be generated in2d. The3d’s reaction rateof chlorine is62.5%, and there has a large number of Friedel’s salt in the resultant and the conversion of Friedel’s salt at this moment to the calcium sulphoaluminatehydration is becoming more apparent.When the calcium aluminum ratio of P+CaCl₂+CO₃^2-+H₂O system is2:1, withthe mass ratio of [CO₃^2-]/[Cl^-] changing, the content of carbonate can’t affect thechloride ion binding ability in the system in2days. When the calcium aluminum ratioof the system is2.5:1, the14d hydration product is Friedel’s salt, The polycarbon,CaAl₂（CO₃）₂（OH）₄·6H₂O, calcium hydroxide, with the reaction process graduallydeepened, Friedel’s salt, high-carbon calciumaluminate hydration andCaAl₂（CO₃）₂（OH）₄·6H₂O gradually change to Ca4Al₂O₆CO₃·11H₂O; the final productcontains Friedel’s salt, and co-exist with Ca4Al₂O₆CO₃·11H₂O in the system.Suitable alkaline reaction of the internal environment can insure the growth ofstrength of stabilized soil. There is no in28d’s product, but Low-sulfur-type calciumsulphoaluminate hydration and AFt, which is consistent with the aforementionedconclusion of water chemistry tests that calcium chloroaluminate hydration willtransform to calcium sulphoaluminate hydration.