Research On Mechanical Properties And Environmental Friendliness Of Loess Reinforced By Industrial Waste

Geopolymer is a kind of gelling material manufactured by polycondensation of raw materials rich in silicon and aluminum in the alkaline environment.This material has such characteristics like high strength,harden rapidly,and eco-friendly,etc.It has the potential to replace cement as the main building material.Loess has visible porosity structures,and will collapse after being exposed to water which has a great impact on the surrounding buildings and structures.In order to reinforce loess,one of the traditional methods is using cement to grout.However the production of cement will produce lots of pollution,and it will produce alkali aggregate reaction.By contrast,geopolymer has become a new type of reliable solidified material recently,there are few studies on geopolymer based on loess.This paper researched shear strength of loess based geopolymer,we ascertained the content of chemical components of geopolymer which is suit for loess in Qing Hai area.Research shows the mechanical properties of loess rise first and then fall with the mass of activator or alkali increased,and the mechanical properties of loess decreased continuously with the rising of activator modulus.The optimum mass of activator and alkali are 30% and 15% of the optimal soil moisture content,respectively,and the optimal modulus of activator is 1.0.Cohesion increases about 10 times to 163.35 k Pa with this composition,and the internal friction angle increases about 5°.This paper also considered two kinds of industrial wastes as raw materials to produce geopolymer.Through comparing mechanical properties of different kinds of geopolymer reinforced loess,loess and cement loess under the same silica-alumina ratio,it can be ascertained that the possibility of utilizing geopolymer replace cement.The optimal geopolymer is based on slag,its cohesion reaches 309 k Pa after curing for 14 d and internal friction angle increases about 12°,those properties even surpass cement loess curing for 28 d,respectively.The ingredients of geopolymer raw materials and chemical drugs do not contain or are far lower than the control value required by national standards through analyzing and comparing components respectively.Finally,SEM tests of all samples were conducted in this paper,and microscopic parameters were obtained by combining with PCAS software.The effects of the geopolymer addition were summarized through quantification and comparison of porosity structure parameters.The research shows that the addition of polymer significantly reduced the porosity of the loess,the sense of particles are significantly diminished,integration phenomenon appears by glue material coupling particles.The contact form between particles also appeared to change,the shape of the particle and pore becomes more pliable,and pore distribution becomes more random.