Study On Composite Soil Coat Of Impermeable Materials With Toughness

Composite soil coat of toughness is an impermeable material which mainly contains clay. People usually used the soil mixed the tung oil, sticky rice juice materials to construct China's ancient city wall and tomb in order to improve bond strength, durability and impermeability of the soil and achieved good results. The urbanization has expanded living space of human beings to the ground floor and brought about the problem of how to dispose urban waste. Then impermeable material for the cover of ground floor and the landfill projects has been crucial to the successful prevetion of seepage.Composite soil coat with toughness is a new type of impermeable material, which adopts ancient approach of dealing with geotextile materials, combines modern materials and test design. In its early stage, it has such quality as good liquidity in its early stage, low permeability and good toughness in its later stage that it can be applied in the basement and waste landfill projects.This article focused on working out composite soil with the red clay as the main content, fly ash, bentonite, sticky rice juice, quicklime as the additive by using the method of orthogonal optimizing design. Some works have been done according to the geotechnical characteristics of composite soil: (1) using joint instrument liquid plastic limits to measure the liquid and plastic limit; (2) shear test, to determinate the changes in shear strength of composite soil in about 7 day, 14 day, 28 day; (3)without proloading carrying out infiltration tests, on the composite soil samples at 28 day, 60 day and 90 day respect to determine dry and wet density, permeability, and other changes; (4) analyzing the main factors and the optimal portfolio of the shear, the permeability characteristics with the test datas and range analysis method;(5)comparing composite soil with the original red clay in micro-level by the scanning electron microscope, X-ray diffraction.The following conclusions can be drawed based on the collation and analysis observation data.1. Composite soil materials become larger in strength over time, and the main influential factors on the composite soil shear strength are fly ash and sticky rice juice;2. The permeability of composite soil material decreases over time.The permeability of the composite soil can meet the regulatory requirements of '1×10^-7 cm/s' with no effective stress;3. The composite soil sample of 8^# could both meet the requirements of smaller change in the intensity of toughness strength, but the lower permeability;4. By using the soil powder technology, the composite soil is easy to construct only by trace and pour. It needs no ram pressure and has no lap joint. So it's in favor of large-scale construction.