Study On Water Absorption And Water Loss Performance Of SH And Lime Solidified Soil

China is an ancient civilization with a splendid history.There are a large number of earthen sites in various parts of China.Most of these sites are located in the northwest,in a dry environment,and many in the wet areas of the south.In the long-term natural weathering,these earthen sites are on the verge of destruction,causing major economic and cultural losses.Therefore,research on the reinforcement and protection technology of earth sites is very important.Different from other buildings,the earth sites have high requirements for solidified materials.For the reinforcement and protection of the dry soil sites in the northwest,a lot of research has been done by the predecessors,and many new materials have been developed and used.SH is a new type of polymer material independently developed by Lanzhou University.It has the advantages of non-toxic and harmless and low price.Lime is the earliest reinforcement material used in human history.It has also been successfully used in the reinforcement and protection of northwest earthen sites in recent years.The development of the disease of soil sites is closely related to the role of water.It is necessary to study the interaction characteristics between soil and water,and to study the performance of materials in water absorption process and water loss process.Based on the water absorption and loss process of SH and lime solidified soil,the boundary moisture content of the solidified soil,the wave velocity and the volumetric shrinkage rate during the curing period were determined.The capillary water absorption test,the equilibrium moisture absorption and desorption test,and the pressure film dehydration test were studied.The relevant hygric properties of the solidified soil were evaluated.The ability of the material to resist water erosion was evaluated by water repellency test and water stability test.Finally,the salt-blocking effect of the new polymer material SH was evaluated by water-salt migration test.Through the above tests,the following main conclusions were drawn:(1)SH and lime both increase the liquid plastic limit of soil,but the plasticity index of soil decreases with the increase of lime and increases with the increase of SH.Both SH and lime can limit the shrinkage of the soil,but the lime performs better.(2)With the increase of SH solid content,the water absorption and capillary properties of soil samples were greatly weakened,and the SH-reinforced soil samples with 0.7% solid content produced almost no capillary phenomenon.The 6%~10% lime content and SH composite reinforcement effect are better,which can reduce the water absorption of soil samples.In the isothermal absorption and desorption curve,under the conditions of low humidity and high humidity,the lime makes the equilibrium moisture content of the soil sample increase.The addition of the curing agent mainly changes the binding site and bonding strength of the soil particles and water molecules.The single layer adsorption energy constant is worthy of variation in the GAB model.In the soilwater characteristic curve,both SH and lime play the role of increasing the intake value and reducing the water storage coefficient,showing the characteristics of water loss and the composite reinforcement effect.(3)With the increase of SH solid content,the soil begins to show obvious water repellency,and it has been in extreme water repellent state at 0.7% solid content.It can be considered that the addition of SH changes the solid-liquid contact angle of the soil,0.6% of SH is the boundary point between the hydrophilic-water repellency of the solidified soil.In terms of water stability,the addition of lime promotes the water stability of SH.The composite reinforcement effect of 6% lime and SH is good.The high-dose lime and SH composite reinforcement is not conducive to the improvement of water stability.(4)SH has obvious salt-blocking effect.When the SH solid content reaches 0.6%,the capillary water can be limited to 20 cm,and the salt limitation has a significant effect on the rise and enrichment of capillary water.The relevant research results obtained from the experiment have reference significance for the application of SH in the field of moisture protection and waterproof protection of soil sites,and made the exploration to expand into the field of reinforcement of soil sites in wet areas.