Discuss Ofthe Early Hydration Properties And Setting Mechnism Of Silicate-type Cements

THROUGH MEASUREMENTS ON CONDUCTANCE OF CEMENT PASTES AND CEMENT-WATER SUSPENSION, CA+2 AND OH'1 CONCENTRATIONS OF CEMENT-WATER, CONTENTS OF CHEMICALLY BOND WATER, ACIDICALLY NON - SOLUBLE CONTENT AS WELL AS ANALYSES ON SIEVING RESIDUE, WATER DEMAND FOR NORMAL CONSISTENCY, TOTAL SO3 CONTENT IN CEMENT AND SETTING TIME, THE EARLY HYDRATION PROPERTIES OF SILICATE-TYPE CEMENTS ARE INVESTIGATED IN THIS PAPER IN ORDER TO LOOK FOR THE RELATIONS AMONG THESE EARLY HYDRATION CHARACTERISTICS AND CEMENT SETTING PERFORMANCE. CEMENT MANUFACTURERS, CEMENT TYPES AND STRENGTH GRADING ARE NOT TAKEN INTO ACCOUNT FOR THE SAMPLES AS IN THIS INVESTIGATION. IN THIS RESEARCH , SAMPLE EXTRACTING METHOD FOR HYDRATING SUSPENSION IS RENOVATED , SHORTENING THE RELATED EXPERIMENT PERIODS AND IMPROVING THE EFFICIENCY AND SYSTEMATISM. A SPECIAL VIBRATING STAGE AND COMPUTERIZED DATA-COLLECTING HARDWARE AND SOFTWARE ARE PREPARED AND EMPLOYED FOR PASTE CONDUCTANCE MEASUREMENT IN THIS RESEARCH.RESULTS OF THIS INVESTIGATION REVEAL THAT PERTINENCE BETWEEN INITIAL AND FINAL SETTING TIME IS MORE STRONGER, INDICATING THE CONTINUITY OF SETTING STRUCTURE DEVELOPMENT DURING EARLY HYDRATION PERIOD. MEANWHILEANALYSES REVEAL THAT THE INDIVIDUAL INDEX OF TOTAL SO3 CONTENT IN CEMENT, WATER DEMAND FOR NORMAL CONSISTENCY, SIEVING RESIDUE HAS NO APPARENT RELATION WITH CEMENT SETTING TIME, THUS BY THESE INDIVIDUAL PROPERTY THE CEMENT SETTING PERFORMANCE IS HARDLY PREDICTED. DURING THE EARLY HYDRATION PERIOD IT IS FOUND THAT THE PERTINENCE AMONG CHEMICALLY BOND WATER PERCENTAGE AND INITIAL AS WELL AS FINAL SETTING TIME ARE VERY EVIDENT. IT IS ALSO NOTED THAT THERE IS SOME DISPERSION IN THIS PERTINENCE, IMPLYING THAT THE CHEMICALLY BOND WATER CONTENT DURING HYDRATION EVOLUTION IS NOT THE UNIQUE SUFFICIENCY TO CONTROL THE SETTING PERFORMANCE OF CEMENT.BY DISCUSSION ON THE MODEL OF CEMENT SETTING, IT INDICATES THAT THE INITIAL POROSITY OF PASTES WOULD DESCEND WITH THE ASCENTMENT OF CEMENT HYDRATION DEGREE. WHEN CEMENT ARRIVE INITIAL SETTING, HOWEVER, THE EXTENT OF INITIAL POROSITY DESCENTMENT VARIES MUCH FROM SAMPLE TO SAMPLE, REVEALING THAT SETTING NETWARE DENSITY IS NOT THE ONLY CONTROLLING FACTOR ON CEMENT SETTING PERFORMANCE. AT THE SAME TIME, THIS PAPER ALSO ANALYZES THE INFLUENCES OF POLY-FACTORS ON CEMENT SETTING PERFORMANCE BY GRAY THEORY AND, THE OBTAINED CORRELATION RESULTS PROVIDE USEFUL DIRECTIONS FOR FURTHER INVESTIGATION. WITHIN THE SAMPLE RANGE APPLIED IN THIS RESEARCH AND WITH SETUP OF GRAY THEORETICAL POLY-FACTOR ZERO-DEGREE DIFFERENTIAL FORMULA G (0,N), CEMENT SETTING PERFORMANCE COULD BE PREDICTED THROUGH CEMENT HYDRATION CHARACTERISTICS AND PROPERTY INDEX.