Study On The Subgrade Diseases In Permafrost Of Qinghai-tibet

Carbon materials on improving the strength of cement base material and has great potential value to expand its functional, and graphite oxide particles has mechanical properties and surface activity, at present, micro graphite oxide in cement base material study is less, this paper improved the ball milling method, micro graphite oxide, and its incorporation into the cement base material, a preliminary probe into its effect on the properties of cement base material. This thesis mainly includes:①Micro graphite oxide preparationUsing improved method of ball mill, aluminum powder mixed with graphite ball mill for 1 hour, again with hydrogen peroxide(H2O2) at 160 ℃ high pressure reaction kettle response within 1 hour, after drying made micro graphite oxide, and by using XRD, SEM, ir, and atomic force microscope for raw materials and micro graphite oxide characterization. Results show that the sample size between 1-100 nm, but the big particles is more focused on the 45-75 nm, graphite crystals are destroyed, no longer flat surface, the jagged edges, and with the rich oxygen containing groups such as carboxyl(-cooh) group- hydroxyl(OH), epoxy groups(-o-) and so on, has a larger specific surface area and surface activity.②Cement mortar, net pulp performance researchSample of the reaction with pure calcium sulfate, calcium hydroxide, the results show that na micro graphite oxide can promote the crystallization of calcium sulfate and calcium hydroxide, not generate new substances, envisioned as a nucleus, calcium sulfate and calcium hydroxide in the surface crystallization, crystal compared to the same size, but the degree of crystallization slightly decreased.Sample of the net mixed with cement slurry, the results show that the graphite oxide can delay the cement hydration, initial setting time prolonged, but has little effect,and make higher hydration reaction of hydration heat, oxidation, micro graphite particles can improve the microstructure of cement hydration products. Micro graphite has a promoting effect, make the micro crystal morphology neat, with the increase of na micro graphite content, cross section structure is more and more dense, uniform crystallization product also more and more small, less space with the increase of mortar.Sample of the mixed with cement mortar, the results show that nanometer graphite oxide can improve the liquidity of mortar, when the dosage of 1%, increased by 7.9%,relative to the benchmark sample at the same time, the bibulous rate of mortar specimen and decreased with the increase of dosage, flexural and compressive strength of mortar in 3 d lower than the benchmark samples, the 7 d mechanical strength with benchmark samples were similar, at 28 d compressive strength, bending strength relative to a benchmark specimen respectively increased by 29.1%, 30.5%;③Alkali resistance, sulfate corrosionAlkali corrosion resistance was studied at the same time, with the increase of dosage, the durability of mortar increases, but the content is more than 0.5%, the durability of little change. C curing method helps to improve micro graphite oxide modified mortar strength.