| At present,the annual ceramic production and consumption in China has been ranked first in the world,but it also bring a hugh amont of ceramic waste.Ceramic polished tiles are high-grade building decoration materials developed in recent decades,and the output is still increasing year by year.However,due to the grinding and polishing process,polishing waste and semi-finished waste can not be avoided.The ceramic polishing waste is not only rich in active silica,which can react with pozzolan,but also has the similar particle size as cement.If the ceramic polishing waste can be used in mortar or concrete production,it can not only solve ceramic products,but also reduce the carbon emission caused by the production of cement.Traditionally,in the application of recycled material powder(RMP)in concrete,a common method is to replace part of the cement with RMP to produce concrete.This method is called “cement replacement method”.In recent years,some scholars have proposed a new alternative method,namely “paste replacement method”: replacing some cement paste(water + cement)with RMP,but with the water/cement(W/C)ratio unchanged.At present,the systematic research on the cement replacement method on polishing ceramic waste is little,and whether the paste replacement method is suitable for polished ceramic waste is still unknown.Therefore,launching study on the ceramic polishing waste(CPW)based on these two methods is necessary ad valuable.In the thesis,40 morar mixes with different proportions were designed by cement replacement method and paste replacement method,and produced for carrying out different tests to evaluate various properties of the mortar.Main contents are as follows:(1)Based on the cement replacement method,mortar mixes with different W/C ratios and CPW contents as cement substitution were made for carrying out mini slumpflow test,cube compressive strength test and coulomb electric flux test.The results show that with the increase of CPW content,the dosage of superplasticizer(SP)used to maintain the preset workability increases,and the 7-day strength rises and then decreases,and the 28-day strength increases slightly.The adding of CPW can significantly improve the chloride resistance of mortar,and and the effectiveness is higher with a higher CPW content.In addition,based on the Hobb's strength prediction formula,a 28-day strength prediction model of CPW was established,and the strength cementing efficiency of CPW was quantified.The analysis results show that the strength cementing efficiency factor(CEF)of CPW is slightly higher than that of cement,and the optimum The analysis results show that the strength(CEF)of CPW is 1.6.(2)Based on the paste replacement method,mortar mixes with various W/C ratios and CPW contents as paste substitution were produced to launch mini slump-flow test,cube compressive strength test and scanning electron microscope test.The results indicate that: the CPW has a negative effect on workability of mortar,but such effect can be compensated by adding more SP;the addition of CPW can significantly improve the 7-day,28-day and 180-day cube strength of mortar and the increase rate is higher with higher CPW content;the use of CPW can effectively enhance the microscopic structure of mortar.In addition,a mix design method of CPW mortar based on paste replacement method is proposed.(3)Based on the paste replacement method,a series of mortar mixes with various W/C ratios and CPW contents as paste substitution were produced for carrying out sulphate resistance test,carbonation test,water absorption test and dry shrinkage test.The test results show that: the addition of CPW can substaintially reduce the strength loss after sulphate attack,carbonization depth,water absorption rate,drying shrinkage strain and drying shrinkage rate of mortar,and the decreasing rate is higher with higher CPW content.It means that the use of CPW as paste replacement can significantly improve the sulphate resistance,carbonation resistance,water resistance and dimensional stability of mortar. |
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