Experimental Study On Mechanical Properties Of Road Construction Waste And Frerzing Microtruction Under The Condition Of Cyclic Freezing And Thawing Wet

With the acceleration of urbanization, increasing production of construction waste is causing more and more serious environmental pollution. Rational use of construction waste for roadbed can not only solve the environmental pollution caused by it, also release the shortage of resources. The study of construction waste in domestic starts late, many technologies of which are not mature, and the study for subgrade is much less. Referring to some existing research results, the systemic study for construction waste macroscopic mechanical properties and microscopic particle shape feature and contact type are carried out in this paper.Relying on Surrounding North Xi-Xian highway engineering, this paper studies the basic physical and mechanical properties of construction waste through basic physics experiment. At the same time, the anti-freeze test and wetting-and-drying test on the subgrade waste with different mixing proportion are carried on in this paper. The plastic strain changing law and elasticity modulus changing law in the freeze-thaw cycle condition and dry and wet cycle condition are studied in this paper.In addition, it makes scanning the specimens of construction waste come true by using the CT scanning mold which invented in independent. The law of the specimen internal porosity changes with height in the condition of hierarchical compaction is got by studying the distribution of the particles in the longitudinal direction. And the relationship between mixing proportion and porosity and the porosity changing law in the freeze-thaw condition are researched in this paper. And the macro mechanics phenomenon is explained from the micro porosity changing law.The study shows that: the freeze- thaw action and dry-wet cycle action will result in the cumulative plastic strain increases and the elastic modulus decreases in the sample. And 10 times is the inflection point for construction waste destruction at freezing and thawing test. If the cycle times is more than the critical point, the changing speed of plastic strain and elastic modulus is sped up. And 60 times is the inflection point for construction waste in the dry-wet cycle action. If the cycle times is more than the inflection point, the decline rate of the two indexes have a tendency to slow down. There is correlativity among the micro porosity and cumulative plastic strain and elastic modulus changes in the freeze-thaw condition. With the average porosity is increased by 7%, the elastic modulus decreases by about 13%, and the cumulative plastic strain increases by 20%. With the average porosity is increased by 20%, the elastic modulus decreases by about 40%, and the cumulative plastic strain increases by 50%.