Magnesia Cements: From Formulation to Application

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Magnesia Cements:
From Formulation to Application
Copyright
Contents
Acknowledgments
0 Introduction - Characterization of MgO
	0.1 Introduction
	0.2 Important characteristics of MgO and test methods
		0.2.1 Density and particle sizes
		0.2.2 Chemical analysis
		0.2.3 Crystallite size
		0.2.4 Textural properties
		0.2.5 Chemical reactivity and reactive MgO content
	0.3 Relationships among the most important properties of MgO
	0.4 Categorization of MgO
	Acknowledgments
	References
Part One: Existing magnesia cement technologies
1 Manufacture of magnesium oxide for magnesia cements
	1.1 Magnesium oxide produced from magnesite
	1.2 Formation of macrocrystalline magnesite
	1.3 Formation of cryptocrystalline magnesite
	1.4 Magnesium oxide derived from brucite
	1.5 Mining and processing of magnesite
	1.6 Synthetic magnesia
		1.6.1 Precipitation process
		1.6.2 Settling and compaction
		1.6.3 Washing
		1.6.4 Filtration
		1.6.5 General properties of synthetic magnesia
	1.7 Calcination of magnesium carbonate and magnesium hydroxide
		1.7.1 Calcination of magnesite
		1.7.2 Calcination of magnesium hydroxide
	1.8 Furnaces and kilns
		1.8.1 Introduction
		1.8.2 Multiple hearth furnaces (MHF)
		1.8.3 Horizontal rotary kilns
		1.8.4 Shaft kilns
	References
2 Magnesium oxychloride cement
	2.1 Introduction
	2.2 Phase composition and microstructure
	2.3 Reaction mechanism and kinetics
	2.4 Properties of MOC
		2.4.1 Fresh properties
		2.4.2 Physical and mechanical properties
		2.4.3 Abrasion resistance
		2.4.4 Fire resistance
		2.4.5 Ability to bind various materials
		2.4.6 Influence of raw material quality on the properties of MOC
	2.5 Common degradation mechanisms for MOC and counter-measures
		2.5.1 Deliquescence and efflorescence
		2.5.2 Poor water resistance
		2.5.3 Volume instability
	2.6 Applications of MOC
		2.6.1 MOC products and other applications
		2.6.2 Cost-effective measures for manufacturing MOC products
			2.6.2.1 Use of dolomite
			2.6.2.2 Use of MgCl2 from salt lakes
	2.7 Conclusions and recommendations for future work
	References
3 Magnesium oxysulfate cement
	3.1 Introduction
	3.2 Improvement in water resistance
	3.3 Properties of magnesium oxysulfate cement
	3.4 Magnesium oxysulfate uses
	References
4 Magnesium phosphate cement
	4.1 Review on magnesium phosphate cements (MPCs)
	4.2 Formulation of MPCs
		4.2.1 Magnesium oxide
		4.2.2 Phosphoric acid and acid phosphates
		4.2.3 Retarders
		4.2.4 Additives and fillers
	4.3 Hydration and microstructure of MPCs
		4.3.1 Thermodynamic basis in forming MPC
		4.3.2 Hydration heat
		4.3.3 Hydration mechanism and kinetics
		4.3.4 Hydration products
		4.3.5 Microstructure
	4.4 Properties of MPCs
		4.4.1 Fresh properties
			1) Effect of M/P and w/b
			2) Effect of retarder
			3) Effect of additives
		4.4.2 Setting time
			1) Effect of characteristics of MgO
			2) Effect of M/P and w/b ratios
			3) Effect of retarders
			4) Effect of ambient temperature
			5) Effect of additives
		4.4.3 Strength
			1) Effect of characteristics of MgO
			2) Effect of M/P and w/b ratios
			3) Effect of retarders
			4) Effect of aggregates
			5) Effect of additives
			6) Effect of ambient temperature
		4.4.4 Porosity
		4.4.5 Volume stability
			1) Chemical shrinkage
			2) Autogenous shrinkage
			3) Drying shrinkage
			4) Expansion
		4.4.6 Bonding and anchoring property
		4.4.7 Durability
			1) Wearing resistance
			2) Steel corrosion resistance
			3) Water stability
			4) Salt corrosion resistance
			5) High-temperature stability
	4.5 Applications of MPCs
		4.5.1 Structure repair and reinforcement
			1) Concrete pavement
			2) Civil engineering
		4.5.2 Hazardous and radioactive waste stabilization
			1) Heavy metals
			2) Radioactive elements
		4.5.3 Sealant
		4.5.4 Biomedical applications
		4.5.5 Other potential applications
			1) Foamed concrete
			2) Corrosion and fire protection coatings
			3) 3D printing
			4) Ancient buildings repair
	References
Part Two: Emerging magnesia cement technologies
5 Magnesium silicate hydrate cements
	5.1 Introduction - types of silicate binders
	5.2 Magnesium silicate hydrate cement
	5.3 Conclusions
	References
		General reference
6 Carbonated magnesia cements
	6.1 Introduction
	6.2 Carbonated magnesia cement in masonry blocks
	6.3 Carbonated magnesia cement in ground improvement
	6.4 Carbonated MgO binary and ternary cement systems
	References
7 Magnesia in alkali activated cements
	7.1 Introduction
	7.2 Role of inherent MgO in AAC
		7.2.1 Effect on the hydration products
		7.2.2 Effect on the hydration properties and carbonation resistance
	7.3 Effect of additive reactive MgO on the properties of AAC
		7.3.1 Reactive MgO as an activator
			7.3.1.1 Hydration mechanism and reaction products of MgO-GGBS paste
			7.3.1.2 Properties of MgO-GGBS pastes
		7.3.2 Reactive MgO as an additive in AAC
	7.4 Applications of MgO-bearing AAC
		7.4.1 Ground improvement
		7.4.2 Stabilization/solidification for contaminated soil
		7.4.3 Concrete
	7.5 Conclusions and recommendations for future work
	References
8 Magnesia as an expansive additive
	8.1 History of MgO expansive cement and concrete
		8.1.1 Brief introduction to conventional expansive cements and additives
		8.1.2 History of MgO expansive cement and concrete
	8.2 Hydration and expansion of MgO in cement-based materials
		8.2.1 Hydration of MgO
		8.2.2 Hydration and expansion of periclase in cement clinker
		8.2.3 Hydration and expansion of MgO expansive additive
		8.2.4 Factors influencing the expansion of MgO expansive additive in cement-based materials
	8.3 Performance of concrete with MgO expansive additive
		8.3.1 Expansion
		8.3.2 Mechanical performance
		8.3.3 Soundness
		8.3.4 Durability
	8.4 Application of MgO in shrinkage compensation and cracking mitigation of concrete
		8.4.1 Application in hydraulic mass concrete
		8.4.2 Applications in other civil constructions
		8.4.3 Other applications in cement materials
	8.5 Manufacture of MgO expansive additive
		8.5.1 Manufacturing from calcination of magnesite
		8.5.2 Manufacturing from alternative sources
		8.5.3 Product quality required for MgO expansive additive
	References
9 Magnesia in self-healing cement and concrete
	9.1 Introduction and overview
	9.2 Expansive additives in autogenic self-healing of cementitious systems
	9.3 Autogenic self-healing in cement using MgO
	9.4 Role of magnesia in autonomic self-healing applications in cement and concrete
		9.4.1 Encapsulation of magnesia within glass tubes
		9.4.2 Pelletisation of magnesia
	9.5 Field trials and applications
	References
Index
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