ANALYSIS OF MECHANICAL CHARACTERISTICS AND CEMENTATION PROPERTIES ON CONSTRUCTION WASTE FILLING SPECIMENS
It is an effective way to control surface subsidence,realize construction waste resources,reduce land occupation area to fill the coal goaf using construction waste.Uniaxial compression mechanics tests and surface hole fraction calculation were produced on 4 groups of 12 construction waste specimens with different cement content.The relationship between cement content and hole fraction was analyzed,the relationships of cement content and compressive strength,peak strain,and elastic modulus were discussed,failure instability modes of specimens were put forward,and the cement content range of filling specimens for peak strength,the strength reasonable range and rapid strength improvement were determined.The results showed that hole fraction and cement content had an antiphase relationship,cement content had a great influence on the stress-strain curve of filling specimens,the four-phase characteristics of the stress-strain curve was significant at cement content 15％,the greater cement content(the less hole fraction),the longer the elastic phase,conversely,the longer the yield phase.As cement content increased(hole fraction decreased),the strength and elastic modulus of filling specimens were increased according to cubic polynomial,and the axial strain showed decreasing,slow,trend to stable.The instability mode of filling specimens with less than 10％cement content was a multi-crack crushing failure,the one with 10％to 15％showed double back-arch shear failure,and the one with more than 15％showed double vertical splitting failure.The cement content range of the construction waste filling body was 7％to 20％according to mine requirements,the strength range 2.3647 to 15.7341 MPa,the peak strength of the filling specimen appeared at the cement content of 18.6991％,and the strength of filling specimens on the 28th day was 1.24 times on the 10th day.
construction wastefilling specimencement materialshole fractionmechanical characteristicsinstability mechanism
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