Study On Characteristics And Application Technology Of Alkali Slag Polymer Filler Soil

A soda slag polymer soil is obtained by the mixture of alkaline slag and fly ash in a certain ratio,combining with an added alkali slag sodium silicate solution at room temperature.It aims at improving the poor properties of stability,resistance to wet and dry cycles,and ability to freeze-thaw cycling,in order to achieve the widely applying of soda slag soil.Through the liquid plastic limit test,compaction test,tri-axial test,water stability test,wet-dry cycle test and freeze-thaw cycle test,the physical and mechanical properties and durability of the soda residue polymer soil were tested and analyzed.Combining with micro-infrared spectroscopic analysis,scanning electron microscopy,EDS spectroscopy,and XRD phase detection tests,the microscopic mechanism were investigated.The main research contents and conclusions are as follows:(1)On the basis of previous research,the optimal ratio of alkali slag and fly ash for Soda Plant was found to be 2:1 by the liquid-plastic limit test and compaction test of alkali residue soil with different ratios under the room condition.Then,the alkaline-earth polymer soil was prepared,and macroscopic mechanics characteristics of the alkaline-earth polymer soil and the mechanical properties of the alkali-earth were comparatively analyzed.It was found that the strength of the alkali-earth polymer soil was increased by 4-9 times.The cohesion and internal friction angles were improved by about 2 times comparing with the alkaline residue soil.The mechanical characteristics were improved.(2)Through testing the water stability of the soda residue polymer soil,wet and dry cycle test and freeze-thaw cycle test,the durability performance of the soda residue polymer soil was tested.The durability of the soda residue polymer soil was significantly greater than that of the soda residue soil.The amount of alkaline activator is 5%of the dry weight of the alkaline residue,which is the most economical application.The water stability coefficient of the soda residue polymer soil under this doping ratio is improved to0.93,and the strength loss after ten dry and wet cycles is reduced to 8.69%.After only 5 freeze-thaw cycles,the strength loss was 17.4%,and the durability of soda residue was improved.(3)The infrared spectrum(FTIR)analysis test,electron microscope scan test,energy spectrum analysis(EDS)test and XRD test are applied on the improved soda residue polymer clay.FTIR showed that the addition of sodium silicate to the soda slag polymer soil promoted the polymerization of Si-O-Al bonds,resulting in the formation of aluminosilicate gels.The "bulging" peak in the XRD line shifted to the right at a high angle.It can be proved that there is a new gel material.The SEM image showed that after the fly ash is eroded,gel substances are formed on the surface and around and overlap with each other to form a whole.The EDS test results showed that the Si/Al content in the gel material was between 1 and 3,and the Si/Al ratio increased with the increasing of the amount of activator in this range,in which the durability of the soda ash polymer clay also increased.