Abstract: To improve the stability of sandy slope and achieve ecological slope protection, a kind of eco-ester-polymer named as Aqua-Dispersing-Nano-Binder (ADNB) was used to reinforce sandy soils. Properties of molecular weight and thermal stability of ADNB were tested through gel permeation chromatography (GPC) method and thermogravimetric (TG) method. The effects and the regularity of strength improvement of sandy soils were studied by designing and carrying out tests of unconfined compressive strength (UCS) and direct shear under the condition of different ADNB dosages. Finally, the disintegrating test and the slope scour model test have been performed to investigate the improvement effect and regularity of both water stability of sandy soils and the anti-erosion ability of slope surface, and the improvement mechanism of sandy soils and ecological slope protection was further analyzed. Results show that ADNB can improve the strength and water stability of sandy soils, and the erosion resistance of sandy slope surface is improved. With the increase of ADNB dosage, the UCS and cohesive force of sandy soils are increased, in which the increase of cohesive force is 46%-77% while internal friction angle has no significant change; the peak disintegration rate and the disintegration coefficient of sandy soils decreases, besides, the occurrence time of the maximum disintegration rate is more and more delayed; the erosion rate of slope surface decreases about 68%-86%. The application effect of slope protection engineering shows that ADNB performed well on stabilizing soils with a long time and promoting the vegetation growth. As a result, the long-term ecological protection of slope is achieved.

Key words: eco-ester materials, sandy soils, water stability, erosion resistance, vegetation growth, ecological slope protection