New Geotechnical Inorganic Adhesive Research, And Its Compressive Strength Performance

Since organic adhesives have many disadvantages such as constructing troublesomely, inferior aging resistance, large shrinkage, high price, polluting environment, harmful to people and so on, the inorganic adhesives (silicate adhesives) are studied. This kind of adhesive has good affinity with soil and concrete, and it is innocuity and savorless, and it can be constructed conveniently and reliably, and the price is low, so it has many incomparable properties that the organic adhesive can't reach.On the basis of previous study, it is ideal to choose silicate inorganic adhesive, in which water-solubility sodium silicate is used as essential material, sodium fluorosilicate or phosphoric acid is used as solidified agent, as soil adhesive. Through orthogonal test, the better is that the high and low modulus of sodium silicate account for one half respectively, the adding content of sodium fluorosilicate must be 20% more than sodium silicate, the adding content of phosphoric acid is 2% of sodium silicate.Adhesive experiments are made with different soil and the results indicate: soil adhesive has extensive adhesive, silicon dioxide and some substance of felspars play a great part in increasing compression strength. Adhesive experiments are made with adhesives of different solidified agent and soil, the results show: with the increase of solidified agent, compression strengthincreases gradually. When it is five portions, compression strength can reach maximal value, if solidified agent continues to increase, compression strength decreases instead; it can illustrate that the solidified agent has a great influence on the adhesive properties of adhesive soil. Compression tests on adhesive soil of different silicon dioxide are made and the results show: compression strength increases with the increase of silicon dioxide content. The tests of cementation with thin soil show that the properties of adhesive thin soil are superior to those of adhesive thick soil, so the size of soil grain affects adhesive properties a lot. The comparable tests with cement of the same size are also made.The cementation experiments are made on impermeability and flexural strength and the results indicate: after cementation of soil adhesive and soil, it has good impermeability and flexural strength.Through the above analyses of properties, the adhesive mechanism is further studied. The essence of which is that the silicon dioxide sol produced through the reaction of water-solubility sodium silicate and sodium fluorosilicate is changed into silicon dioxide gel, and phosphoric acid supplies H+ to turn silicic acid into silicic acid gel so as to form reticular structure.