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Mechanochemical Modification Powder Construction Waste

Posted on:2010-01-26Degree:MasterType:Thesis
Country:ChinaCandidate:Y YuanFull Text:PDF
GTID:2191330332976847Subject:Environmental Engineering
Abstract/Summary:PDF Full Text Request
The advantage of mechanochemistry during practical application is:to make the granularity small; cause the surface area large and heighten the activation of substance. Still more, we can mix different substance well and reduce the depletion of energy and material by mechanochemistry method. Recent years, mechano-chemistry method is used comprehensive and it is used continuously into many new territories.Mechano-chemistry method is used in mineral powder and waste, but to treat industrial wastes such as Pyrite, Thalheimite, Bauxite, etc yet. There have not people to use mechano-chemistry method in the residue of construction waste. And the residue of construction waste is not to be utilized well yet either.Here, when the grain diameter of construction wastes smaller than 5.00mm, we call it residue of construction waste. We could achieve the aim that Control of environmental pollution and save materials by use of construction waste powder.First, we analyze the residue of construction waste by XRF & XRD. The results show that the chemical compound of residue of construction waste as same as the fly ash, silicon powder and cement, the gross of CaO, SiO2 and Al2O3 of the residue of construction waste more than 85%. The residue of construction waste contains a large number of CaSiO4·2H2O and CaAl2Si2O8·4H2O. It proves that residue of construction waste have active in theory.Second, try to research the modification effect of residue of construction waste by mechanical lapping. The degree of fineness and specific surface area of residue of construction waste can give us the answer that there has mechano-chemistry effect in residue of construction waste by mechanical lapping. We control the grinding process parameters:grinding time between 2h to 6h, ratio between grinding balls and raw material is 2:1, fill rate is 70% and dry. When the grinding time is 4h, the degree of fineness is 3.5% in 3:1 ratio between grinding balls and raw material, the degree of fineness is 5.8% in 2:1 ratio between grinding balls and raw material, they are up to snuff of the masonry cement, the best specific surface area of residue of construction waste is 749m2/kg. So we could say that we can activate the residue of construction waste.One more time, we use the activating residue of construction waste to make little modle as supplementary cementitious component. When the grinding time between Oh to 4h, the pressive strength of modle crescent. The results show that, there has active in residue of construction waste and it can be excite. Then we generalize the coptimum conditions.Finally, we can see that mechano-chemistry method is very well when it be used in residue of construction waste by a series of experimental investigation. By mechano-chemistry method, the models we manufactured have good physicochemical property, when add to sodium hydroxide solution 8mol/L, the models' physicochemical property is better; the 7 days pressive strength of it is 23.5MPa. Moreover, the targets of models are to be in line with the GB3183-2003. In a sense, we could use the residue of construction waste as the admixture of masonry cement.
Keywords/Search Tags:residue of construction waste, mechanochemistry, transnature, additive, activation
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