Experimental Study Of Engineering Properties Of Loess Reineforced By Consolid System

The Consolid system as a chemical reinforcement reagent that has been succesfully used worldwide to improve the engineering properties of soils. However, few studies address the application of the Consolid system in the Huangtu Plateau(China). Here we tested the Consolid reagent for the improvement of loess soils form Qingyang and Lanzhou, thus to evaluate the feasibility of Consolid system applied in loess region of China. Laboratory tests conducted include Atterberg limits tests, compaction tests, unconfined compression tests, swelling tests, the drying shrinkage tests, water drop penetration test and permeability test in diverse mixed ratio of the Consolid system to bulk solid. And the chemical composition and mineral composition were studied by X-ray diffraction. Test microstructures analyzed by scanning electron microscope and mercury porosimeter. The results show that, with the increasing proportion of Consolid system in the mixture, the liquid limit, plastic limit, plasticity index, optimum moisture content, compressive strength, anti-disintegration property, the water drop penetration time and the mass loss rate increased. While the maximum dry density and the swelling percentage decreased. The linear drying shrinkage percentage decreased followed by increased. And there is little change in the hydraulic conductivity. The optimum proportion of Consolid system added into loess soils is suggested to be 2%～2.5%, which made a comparable improvement of loess modified by the 5% modified cement or 5% modified lime, with respect to requirement of engineering construction in loess area of China. There are amorphous dispersing diffraction peaks and new crystals showed in the samples of loess reinforced by Consolid system. The SEM images showed that the gel films increased with elevated Consolid system content, and new crystals also were found. MIP test indicated that the total area of pores increased with the Consolid system content increasing, while the diameter of minimum pore decreased. This proves that the increase in the gel films and new crystals resulted in a decrease macropores and an increase micropores. The impeovment of loess reinforced by Consolid444+Solidry additives is attributed to the bond strength of gel films and new crystals in microstructure and formation of three dimensional networks of frame.