1st Edition

Supplementary Cementing Materials in Concrete

By Michael Thomas Copyright 2013
    210 Pages 114 B/W Illustrations
    by CRC Press

    210 Pages 114 B/W Illustrations
    by CRC Press

    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.

    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

    Biography

    Michael Thomas is a Professor in the Department of Civil Engineering at the University of New Brunswick, as well as a registered professional engineer. He has been working in the field of cement and concrete research since 1983.

    "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."
    ––Concrete International Magazine, August 2013