Study On Capability Of Resisting Sulfate Corrode Of â…¡ Fly Ash Concrete In Xinjiang Saline Soil Area

In order to solve the widespread problem about the concrete eroding by sulfate in the saline areas, and make full use of theâ…¡Fly Ash resources which located in Xinjiang, we made concrete and mortar specimens configured with theâ…¡fly ash. From the test, we analyzed that on the concrete strength characteristics and anti-sulfate ability in the case that the water cement ratio are 0.40, 0.35 and 0.30, and volume ofâ…¡fly ash are 30%, 40% and 60% respectively. The groups specimens were observed in microscopic morphology and analyzed by electron microscopic. The research showed:(1) To the mixedâ…¡fly ash concrete, the main factors which affected the strength are the water cement ratio, the quantum of the fly ash and the time period. With the decrease of water cement ratio, the compressive strength of concrete increased at the same time period, especially when the water-cement ratio reached at 0.1, the change was obviously.(2) With low water-cement ratio and proper super water reducing agent, making the high mixedâ…¡fly ash concrete by the techniques of the high performance concrete, although strength was low in the early period, the intensity became stronger later. It indicated that filling of the micro collection materials aboutâ…¡fly ash was more significant, and the hydrating performed obviously for the compressive strength in the later period. Through controlling of the water-cement ratio and fly ash gradeâ…¡, we can prepare to meet the different strength requirements of the general engineering.(3) The anti-erosion coefficient of the mixedâ…¡fly ash specimens were higher than the ordinary ones, especially when the quantum of the mixedâ…¡fly ash reached 60%. The anti-erosion coefficient was significantly higher than the others. It suggested that the more quantum of the mixedâ…¡fly ash could improve anti-sulfate erosion.(4) At the short curing time(3 days), with low water-cement ratio, and when the mixedâ…¡f ly ash was up to 60%, the effect was remarkable to resistant the high concentration solution (sulfate ion concentration was 8000mg/L, 20250mg/L). Therefore, when it was difficult to avoid the high concentrations of sulfate after concrete placement, we had better use the great more mixedâ…¡Fly Ash to configure high-performance concrete at the low water-cement ratio, then the anti-erosion ability of concrete would improve economically and effectively.(5) After immersing in the high concentration of sulfate solution, the surface of mortar specimen configured at a low water cement ratio would be loose and broke gradually, and the loose layer of materials contained a lot of gypsum. It was not found the phenomenon that a large number of specimen filled with more Aft expansion.