Research On Preparation Of Different Water Cement Ratio Cement Grouting Materials And Its Properties

With the rapid economic development, the scale of various kinds of high-rise block, skyscraper or underground engineering has become increasingly large, requirements for the security of the project has also gradually enhanced, grouting is an important way to solve those problems above.On the one hand, with the push of energy conservation and emission reduction, combined with the resources available in China, Super sulfate cement (SSC) known as "green" of low pollution prepared by using graining blast furnace slag can prepare the grouting materials of low water-cement ratio. The results showed that when the content of slag is above 80%, the compressive strength of 28 days can reach 60MPa above. Silica fume has more influence on the liquidity of the SSC grouting materials than metakaolin, the polycarboxylate superplasticizer can improve the liquidity of SSC grouting materials greater than melamine water-reducer, but these two water-reducers has little difference of the effect on the value of the strength. The introduction of the water-reducer can affect the values of contraction-expansion of SSC paste, incorporating that paste show no any phenomena of shrinkage without adding the water reducer and appear shrinkage after the addition of the water-reducer in different ages. Silica fume and metakaolin have great effect to the strength of 3 days of the SSC grouting material with the mixing alkaline activator amount of 1%, 3%, but have little influence to the strength of 28 days. Water-cement ratio and curing way affect the shrinkage of the SSC paste differently, the SSC paste show shrinkage by the curing process of constant temperature in air, and show slight expansion by the water curing when the mixing amount of alkaline activator is 1%.The main reason of the carbonation of the SSC paste is that the hydration products is mostly ettringite which is easy to form porous skeleton structures. So the CO2 from outside is liable to intrude the paste to conduct acid-base reaction. The carbonation rate of SSC can be improved by the foaming of the air-entraining agent to block the interlocking pore and by the filling and tightly-piled effect of the microaggregates.The main hydration products are ettringite and hydrated calcium silicate gel by the micro-analysis of the SSC paste, abundance of gypsum crystals included. On this basis, the figure of the SSC hydration process is proposed.On the other hand, it requires high water-cement ratio to meet requirements of some superfine sand or the reinforcement of finer interspace, the grouting materials are prepared with the water-cement ratio of 1.0,1.5,2.0,3.0 in this paper respectively.lt should meet the high flow state and the stability of the paste, and the result showed that the welan gum was the best stabilizer and the cellulose ether is the worst stabilizer. Coordinated with the melamine, the welan gum can create the best result. The water-cement ratio affected the strength greatly, the admixtures little opposed, when the water-cement ratio were 1.0,1.5,2.0,3.0 and its strength were 15.4MPa,3.9MPa,1.6MPa,0.9MPa respectively at 28 days. The rheological properties were tested and the rheological modelcalculated which had good match with the Herschel-Bulkey Model with the correlation coefficient beyond 0.96.The viscosity value of the paste mainly depends on the relationship amongst the water-cement ratio, the hydration time of the slurry itself, and mixing amount of the citric acid, not by a single factor. The thixotropy of the paste was influenced mainly by the hydration time of the slurry when the water-cement ratio was 1.0 and 1.5, and by the citric acid when the water-cement ratio was 2.0 and 3.0.