2nd Edition

Manual of Ready-Mixed Concrete

By R Anderson, J D Dewar Copyright 1992

    The new edition of this successful manual has been carefully revised throughout to take account of recent changes and to incorporate amendments required due to the publication of the revised BS 5328. This manual provides information on all aspects of the ready-mixed concrete industry, from the basic materials and their properties to the production, quality control and the use of ready-mixed concrete.

    PART 1: TECHNOLOGY OF READY-MIXED CONCRETE

    Introduction: History of ready-mixed concrete

    Materials for concrete

    Aggregates

    Maximum aggregate size

    Grading

    Silt, clay and fine dust

    Shape and texture

    Water absorption

    Relative density

    Bulk density, void content and voids ratio

    Moisture content

    Chloride content

    Deleterious materials

    Shells

    Uniformity

    Non-standard aggregates

    Making the best use of natural resources

    Moisture movement

    Lightweight aggregates

    Heavyweight aggregates

    Cementitious materials

    Grading, mean size and fineness

    Relative density

    Water demand

    Setting times

    Strength at days

    Ratio of early to -day strength

    Sulphate resistance

    Alkali content

    Chloride content

    Colour

    Ground granulated blastfurnace slag and pulverized-fuel ash

    Admixtures

    Accelerators

    Retarders

    Water-reducers (normal and superplasticizers)

    Air entrainment

    Superplasticizers

    Pigments

    Foaming agents

    Other materials

    Pfa to BS : Part , Grade A

    Silica fume (micro-silica)

    Fibres

    Water for concrete

    Properties of fresh concrete

    Uniformity and stability

    Workability

    Workability test methods

    Pumpability

    Water demand and water/cement ratio

    Rate of change of workability

    Influence of transporting on the workability of ready-mixed concrete

    Cement content

    Aggregate grinding

    Water content and initial workability

    Admixtures

    Ambient conditions

    Bulk volume of concrete

    Transporting method

    Effects of transporting of concrete on strength and workability

    Limitations on delivery time

    Retempering of concrete

    Laboratory simulation of ready-mixed concrete

    Properties of hardened concrete

    Surface quality

    Cracking of concrete

    Strength

    Strength development with age

    Durability

    Concrete mobility

    Covercrete and heartcrete

    A background to specifying durability

    Corrosion of reinforcement

    Chlorides in concrete

    Alkali-silica reaction

    Mix design

    Principles of mix design

    BRMCA method of concrete mix design

    Use of base data from BRMCA mix design method

    Example: selecting batch proportions for specified design mix requirements

    Selection of batch proportions for a prescribed mix

    Example: selecting batch proportions for a standard mix

    The predictable future

    Technical advice on concrete properties based on the BRMCA method

    Mix design using ggbs or pfa

    Example: an adjustment to a mix design for the use of pfa

    Judging concrete mix design

    Water/cement ratio—free or total

    Meeting durability requirements

    Equivalent strength grades—ensuring durability

    Statistics for quality control, mix design and compliance

    Statistical terms

    Variation

    Distribution

    Normal distribution

    Calculations of mean, standard deviation and other parameters

    Sources of variation

    Influence of mean strength level on standard deviation

    Standard deviation due to sampling and testing

    Relevance of standard deviation for concrete mix design

    Statistical implication of compliance rules

    Current compliance rules of BS

    Influence on producer’s risk of faults in sampling and testing for compliance

    Quality control

    Forward control

    Immediate control

    Retrospective control

    Quality monitoring

    The cusum system of strength monitoring

    Principles

    Control of mean strength

    Monitoring of standard deviation

    Significance of trends

    Design of masks

    Advantages over other systems

    Cusum for correlation of predicted and actual strength

    Example: cusum in operation

    Plotting cusum charts

    Action following changes

    Investigation of the cause of a change

    Computerization

    BRMCA concrete control system

    Initial situation

    Test data

    Prediction of 28-day strength

    Mean strength control (by counting rule)

    Standard deviation

    Early-28-day strength relationships

    Sampling and testing ready-mixed concrete

    Sampling ready-mixed concrete

    Effects of non-standard testing on strength

    Simple checks on validity of results

    Communication

    Simple visual checks on the crushed cube

    NAMAS register of test houses

    Interpreting test results for strength

    Apparent compliance failures

    Checking on validity

    Action relating to valid compliance failures

    Establishing strength of concrete in the structure

    Interpretation of in-situ cube strength

    Use of non-destructive testing

    Remedial work

    Increasing the strength and durability of concrete in the structure

    Checking mix proportions or quantities

    Analysis of fresh concrete

    Chemical analysis of hardened concrete

    Checking the quantity of concrete

    Measuring construction volume

    Measuring volume to be concreted

    Measuring volume of plastic concrete after finishing

    Measuring volume of hardened concrete

    Variation in density and yield

    PART 2: PRACTICE

    Production, delivery and quality assurance

    Production methods

    Material types

    Storage capacity

    Processing sequence

    Truckmixer capacity and throughput

    Planning requirements

    Quality control requirements

    Regulatory requirements

    Duration of operations

    Health and safety

    Organizing production and delivery

    Delivery

    Truckmixers

    Tippers

    Conveyors

    Quality assurance

    Specifications and supervision

    Interpreting specifications

    Uses of concrete specifications

    Specifying and supervising the supply of ready-mixed concrete

    Specification clauses

    Checking

    Designated mixes

    Ready-mixed concrete on site

    Choosing ready-mixed concrete

    Site mixing costs

    Ready-mixed v. site mixing supply

    Ready-mixed concrete plants on site

    Site preparations for ready-mixed concrete

    Site/supply liaison

    Setting up a concrete supply

    Programming concrete deliveries

    Ready-mixed concrete on site

    Delivery ticket

    Addition of water at site

    Safety

    Delays

    Placing the concrete

    Compacting the concrete

    Curing the concrete

    Pumping concrete

    The contractor

    The pump hirer

    The ready-mixed concrete supplier

    Organizations

    BRMCA

    BACMI

    QSRMC

    Technical standards

    Order processing

    Technical records

    Plant and production

    Continuing surveillance and enforcement

    NACCB accreditation

    NACCB

    NAMAS

    Appendix 1: QSRMC technical regulations

    Appendix 2: Conversion factors

    Appendix 3: Designated mixes in accordance with BS 5328: Part 2 Section 5 References

    References to standards

    Biography

    R Anderson and J D  Dewar

    'this book will prove indispensable to technical and sales personnel in the concrete industry, and to civil and structural engineers, contractors, architects, and surveyors. Graduate trainees and advanced students will find it a valuable source of reference.' - Concrete Plant and Production

    'The book provides a detailed ready reference for individual sectors of the industry, while at the same time providing the reader with useful perspective on the industry as a whole...this book will provide perspective indispensable to technical and sales personnel in the concrete industry, and to civil and structural engineers, contractors, architects, and surveyors.' - Concrete Abstracts

    'This is a proper manual; it will be of great help to anyone wishing to understand and/or participate in the whole process (and service, as the authors would claim) of providing ready-mixed concrete...It should be noted and welcomed by all sectors of the industry and is a major contribution to the topics...it is excellent value and strongly recommended: the authors deserve congratulations and their industry is lucky to have such representatives.' - Construction and Building Materials