Thomas Supplementary Cementing Materials in Concrete

1. Auflage 2013
ISBN: 978-1-4665-7301-7
Verlag: Taylor & Francis
Format: PDF
Kopierschutz: Adobe DRM (»Systemvoraussetzungen)

E-Book, Englisch, 210 Seiten

Supplementary cementing materials (SCMs), such as fly ash, slag, silica fume, and natural pozzolans, make a significant difference to the properties of concrete but are rarely understood in any detail. SCMs can influence the mechanical properties of concrete and improve its durability in aggressive environments. Supplementary Cementing Materials in Concrete covers the chemical, physical, and mineralogical properties of SCMs; their chemical reactions; and the resulting changes in the microstructure of concrete.

The author links the properties of the material at the microstructural level with its behavior in laboratory tests, and, in turn, to the performance of the material in concrete structures under field exposure. He explains how SCMs influence the mechanical properties of concrete and improve its durability and also covers how various SCMs influence hydration reactions and the evolution of the pore structure and pore-solution composition.

However, SCMs are not a panacea for concrete and improper use may be injurious to certain properties. Achieving the maximum benefit from SCMs requires an understanding of the materials and how they impact concrete properties under various conditions. Drawing on the author’s 30 years of experience, this book helps engineers and practitioners to optimize the use of supplementary cementing materials to improve concrete performance.

Autoren/Hrsg.

Thomas, Michael

Fachgebiete

• Wirtschaftswissenschaften Wirtschaftssektoren & Branchen Primärer Sektor Bergbau

Inhaltsverzeichnis

Introduction
Origin and Nature of SCM’s
General
Fly Ash
Slag
Silica Fume
Natural Pozzolans

Chemical Reactions of SCM’s in Concrete
Pozzolanic Reactions
Hydration of Slag
Effect of SCM’s on the Hydration of Portland Cement
Effect of SCM’s on the Pore Solution Composition

Microstructure of Portland Cement – SCM Systems
Pore Structure
Interfacial Transition Zone, ITZ
Pore Blocking and Mass Transport

Properties of Fresh Concrete
Workability and Water Demand
Bleeding
Air Entrainment
Setting Time

Temperature Rise and Risk of Thermal Cracking
Temperature Rise
Risk of Thermal Cracking

Mechanical Properties

Volume Stability
Chemical and Autogenous Shrinkage
Drying Shrinkage
Creep
Temperature Changes

Durability of Concrete
Permeability
Corrosion of Steel Reinforcement, Chloride Ingress and Carbonation
Resistance to Freezing and Thawing, and De-Icer Salt Scaling
Alkali-Silica Reaction (ASR)
Sulfate Attack
Heat-Induced Delayed Ettringite Formation
"Physical" Salt Attack
Other Forms of Chemical Attack
Abrasion, Erosion and Cavitation

Specifications
ASTM Specifications for SCM’s
ASTM Specifications for Blended Cements – ASTM C 595
ASTM Performance Specification for Hydraulic Cements – ASTM C 1157