During the hydration process, the Ultra-fine Cements present specific physical and chemical characteristics; they are, very short setting time and high heat release. For special applications, such as rapid hardening a...During the hydration process, the Ultra-fine Cements present specific physical and chemical characteristics; they are, very short setting time and high heat release. For special applications, such as rapid hardening and early high strength mortars or concretes, these characteristics can be considered advantageous. Some commercial products used for concrete reinforcement and repairs are the Rapid Hardening Mortars, these mortars must develop a time of setting up to 3 h and an initial compressive strength of about 3.5 MPa once the hardening of the paste is reached. The objective of the present research work is to use Ultra-fine Cement for the preparation of a series of different Rapid Hardening Mortars （with different percentages of Ultra-fine Cement）, these mortars required the addition of a polycarboxylate-base specification F Superplasticizer. It was observed that the optimum water/cement （W/C） ratio for the hydration of the Ultra-fine Cements is W/C = 0.385. The Ultra-fine Cements were obtained by the High Energy Ball-milling technique at laboratory scale, 90% of the Particle Size Distribution is below 11 μm and the Blaine Specific Surface Area is over 9000 cm^2/g.展开更多
The Portland cement(PC)production industry is a key contributor of CO_(2)emission.The demand of cement is mounting day by day due to the rapid infrastructure development in the world.Consequently,CO_(2)discharge from ...The Portland cement(PC)production industry is a key contributor of CO_(2)emission.The demand of cement is mounting day by day due to the rapid infrastructure development in the world.Consequently,CO_(2)discharge from the construction sector is continuously increasing and accounts for about 8%of the total CO_(2)emission,which becomes a global concern nowadays.Wide applications of eco-friendly cements can significantly reduce the CO_(2)release.Therefore,use of magnesium cements(MCs)might be a promising solution to ease such concern.As a rapid hardening cement,MCs can be characterized as low-carbon due to their lower embodied energy and carbon storage ability during the service.This review mainly summarizes the findings of previous studies related to the carbonation performances of PC blended with magnesia and MCs products,and particularly,the influence of Accelerated carbonation curing(ACC)process on the properties of MCs and corresponding CO_(2)sequestration performance.The effects of ACC on mechanical strength,hydration and mineral carbonation mechanisms,pore structures,pore solution pH and thermal properties are discussed.The limitations of existing research are also discussed,which may provide the directions for future research and development of MC material products.展开更多
文摘During the hydration process, the Ultra-fine Cements present specific physical and chemical characteristics; they are, very short setting time and high heat release. For special applications, such as rapid hardening and early high strength mortars or concretes, these characteristics can be considered advantageous. Some commercial products used for concrete reinforcement and repairs are the Rapid Hardening Mortars, these mortars must develop a time of setting up to 3 h and an initial compressive strength of about 3.5 MPa once the hardening of the paste is reached. The objective of the present research work is to use Ultra-fine Cement for the preparation of a series of different Rapid Hardening Mortars （with different percentages of Ultra-fine Cement）, these mortars required the addition of a polycarboxylate-base specification F Superplasticizer. It was observed that the optimum water/cement （W/C） ratio for the hydration of the Ultra-fine Cements is W/C = 0.385. The Ultra-fine Cements were obtained by the High Energy Ball-milling technique at laboratory scale, 90% of the Particle Size Distribution is below 11 μm and the Blaine Specific Surface Area is over 9000 cm^2/g.
基金supported by The Hong Kong Polytechnic University through a University Financial Support for Awardees of Major Renowned Funding and Award Schemes awarded to the corresponding author.
文摘The Portland cement(PC)production industry is a key contributor of CO_(2)emission.The demand of cement is mounting day by day due to the rapid infrastructure development in the world.Consequently,CO_(2)discharge from the construction sector is continuously increasing and accounts for about 8%of the total CO_(2)emission,which becomes a global concern nowadays.Wide applications of eco-friendly cements can significantly reduce the CO_(2)release.Therefore,use of magnesium cements(MCs)might be a promising solution to ease such concern.As a rapid hardening cement,MCs can be characterized as low-carbon due to their lower embodied energy and carbon storage ability during the service.This review mainly summarizes the findings of previous studies related to the carbonation performances of PC blended with magnesia and MCs products,and particularly,the influence of Accelerated carbonation curing(ACC)process on the properties of MCs and corresponding CO_(2)sequestration performance.The effects of ACC on mechanical strength,hydration and mineral carbonation mechanisms,pore structures,pore solution pH and thermal properties are discussed.The limitations of existing research are also discussed,which may provide the directions for future research and development of MC material products.
