Xperimental Study On The Effect Of Cementing On The Strength Properties Of Spherical Particle

The particle arrangement and coupling characteristics make up the soil structural,respectively shows the geometric characteristic and mechanical characteristic.These two characteristics are indispensable ways to research the soil structural.The strength of the mixed cementing materials and their improvement and reinforcement effects are one of the focus of the research problems.In this paper,the research methods of cementation features and the selection of skeleton particles are summarized after summarizing the research progresses of soil microstructure.This article chooses spherical particles as a skeleton,and thinks wax and bentonite as cementing materials to prepare artificial cement specimens.Through conventional triaxial test,this paper attempts to explore the influences on the strength and deformation characteristics of some factors,such as the skeleton granule materials,theoretical void ratioes,confining pressures and wax contents and moisture contents of cementing materials.The specific research works are as follows:1.To explore the impacts of different skeleton granule materials,cementing materials on the strength characteristics of artificial cemented specimens.Two kinds of granular materials —glass balls and steel balls,are choosed in this paper.There are two kinds of cementing materials with mixed materials under different wax volume ratioes and bentonite under different moisture contents.Wax contents and moisture contents are respectively regarded as variables.This paper prepares specimens under six different wax contents and five kinds of moisture contents by triaxial tests under confining pressures of 50 kPa,100 k Pa and 200 k Pa.That indicates by analysising the stress-strain relationships,the strengths of glass balls and steel balls specimens gradually increase with the increase of confining pressures in the wax contents specimens.In generally,the strengths of glass balls specimens are larger than that of the steel balls specimens under the same condition.The waves of stress-strain curves decreases with the increase of the theoretical void ratioes.Among the different moisture contents specimens,the effect of confining pressures on stress-strain curves is little.When the moisture content is less than 37.6%,the strength of steel balls specimen is larger.When the moisture content is 37.6% and more,the result is on the contrary.From the analysis of relationships between wax contents,moisture contents and strength,the minimum strength is at the wax content of 100% under the same condition,and the largest strength of glass balls specimens is at the wax content of 60~66.7%.Both strengths of two knds of specimens decrease with the increase of moisture content.The relationships between moisture contents and strengths show between power functions under different confining pressures.And the curvature of the steel balls specimens is larger.Analyzing the influences of the wax contents,moisture contents on strength parameters,the cohesions of glass balls and steel balls specimens show the same variation trends.In addition to the pure wax conditions,the cohesion of glass balls specimens are generally larger.The overall trends of cohesions and internal friction angles show both falling trends with the increase of moisture contents.2.To further refine effects of skeleton particles and cementing materials on the strength.This paper prepares cementing specimens under six kinds of wax contents and three kinds saturated specimens under different initial moisture contents for direct shear tests,to analyze the relationships between the positive pressures,wax contents,initial moisture contents and the strengths of specimens.Analyzing the test results that indicate the strengths of the specimens under the same condition increase with the increase of positive pressure.Intensity curves show a strong softening and a peak strength under the lower positive pressures.When the wax contents are equal to 50% or less than,and the positive pressure is at 200 k Pa,the intensity curves nearly linear increase and show a strong hardening.Under the different initial moisture contents,the specimens show obvious softening and their softening increase with the increase of initial moisture content.The volatility of stress-strain curves is larger when the initial moisture content is 44.3%.There has been the youngest internal friction angle and the largest cohesion when the wax content is 60%.But the result is on the contrary when the wax content is 33.3%.The internal friction angles decrease with the increase of initial moisture contents.3.In addition,this paper summarizes the failure forms of specimens under different conditions.The damage forms of specimens in triaxial tests can be divided into the upper,middle and lower extrusion destructions and typical shear zone destructions.The destruction locations of the steel balls specimens mobile from lower upwardly with the increase of the theoretical void ratioes under the pure wax condition;When the confining pressure is lower,specimens mainly show typical shear zone destructions under different wax contents.But there are mainly extrusion destructions when the confining pressure is higher.The upper extrusion destructions are mainly appeared in specimens under lower moisture contents.The destruction forms of specimens in direct shear tests are all typical shear sueface destruction forms.4.Compared with previous research contents,the innovation point of this paper is to choose wax and bentonite as cementing materials,which can rule out the influences of a series of complicated factors related to water.In addition,it is convenient to get out skeleton particles by controlling the conditions of wax.This makes the skeleton particles used repeatedly to guarantee the uniformity of specimens.In addition,the sorting testing datas provide a good reference value for the next quantitative analysis and numerical simulation.