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PREFACE

Concrete mix-design is the method to transform the required engineering  properties into the composition of the concrete mixture in terms of kg/m3 of cement, water, sand and coarse aggregate.

The concrete mix design elaborated in this  handbook is based on the EN 197-1 for the cements to be adopted, and the EN 206-1 for the required exposure and consistency classes

This handbook takes into account two types of mix-design depending on the complexity of the required performances: simple or complex mix design.

Simple mix-design is based on the relationships between the concrete properties, on one hand, and the composition of the mixture, on the other, when the concrete properties are the 28-day characteristic strength in the hardened state, and the workability in the fresh state. These relationships depend on the cement strength class and the maximum size of the aggregate.


Complex mix-design is based on the relationships between properties and concrete composition when the properties include durability, permeability, early strength, flexural or tensile strength, besides the 28-day compressive strength. Complex mix-design also includes the calculation of the slump loss depending on the time and temperature transportation, as well as the presence of chemical admixtures.

This handbook also takes into account how to predict drying shrinkage, creep and thermal heating in concrete structures on the basis of the concrete composition elaborated from the mix design.

A special software called CMD (Computerized Mix Design) is available to elaborate automatically simple and complex mix designs.

Price: Euros 130,00 (Delivered free in Europe)

For multiple purchase please contatc info@encosrl.it - BUY ON LINE


INDEX OF THE BOOK "CONCRETE MIX DESIGN"

CONCRETE MIX DESIGN

1      The principle of mix design

2      Types of mix design

2.1   Simple mix design

        2.1.1 Example of a  simple mix design

2.2   Complex mix design

        2.2.1 Example of a  complex mix design

MODULE 1

        Properties of concrete

MODULE 2

        Rheological Properties

2.1   WORKABILITY OF CONCRETE

2.2   MAXIMUM SIZE OF THE AGGREGATE (Dmax) RECOMMENDED FOR SOME TYPICAL CONCRETE WORKS

2.3   WORKABILITY OF CONCRETE MIXTURE AT THE TIME OF PLACEMENT Wp) AS A FUNCTION OF THE TYPE OF STRUCTURE

2.4   WORKABILITY OF CONCRETE AFTER MIXING (WM)

2.5   AMOUNT OF MIXING WATER AS A FUNCTION OF MAXIMUM SIZE (DmaxOF THE AGGREGATES AND WORKABILITY (Wm)
       AFTER MIXING

2.5.1 Humidity of aggregates

2.5.2 Influence of the moist aggregates on the amount of mixing water

2.5.2.1 Influence of the air-dry aggregate on mixing water

2.5.2.2 Correction of the concrete composition with moist aggregates

2.5.2.3 Correction of the concrete composition with air-dry aggregates

2.5.3 Workability prescription as method to check mixing water

2.5.3.1 Concrete producer who does check neither workability nor aggregate humidity

2.5.3.2 Concrete producer who does check workability without knowing the aggregate humidity

2.5.4 Influence of chemical admixtures on mixing water

2.6   INFLUENCE OF Dmax ON THE AIR VOLUME IN THE CONCRETE

2.7   MIX-DESING OF A PUMPABLE CONCRETE

2.7.1 Size characteristics of the sand for a pumpable concrete

2.7.2 Combination of sand and coarse aggregate in a pumpable concrete according to the Goldbeck method

MODULE 3

        Mechanical Properties

3.1   CONCRETE COMPRESSIVE STRENGTH

3.2   THE EUROPEAN NORMS OF CEMENTS

3.3   SYMPLIFIED RELATION OF STRENGTH WITH OTHER PARAMETERS

3.3.1 Cube compressive strength of concrete with cement of class 32.5

3.3.2 Cube compressive strength of concrete with cement of class 42.5

3.3.3 Cube compressive strength of concrete with cement of class 52.5

3.3.4 Cylinder compressive strength of concrete with cement of class 32.5

3.3.5 Cylinder compressive strength of concrete with cement of class 42.5

3.3.6 Cylinder compressive strength of concrete with cement of class 52.5

3.4   HOW TO IMPROVE THE CORRELATION BETWEEN fc AND w/c

3.4.1 How to refine the correlation between the expected results and the experimental one

3.4.2 The relation fc vs. w/c at temperatures other than 20°C

3.4.3 How to correct the strength deviation due to the difference in air volume with respect to the scheduled one

3.4.4 How to assess the presence of accelerating or retarding admixtures on the relation fcu/m vs. w/c

3.4.5 How to take into account lightweight aggregate in the relation fcu/c vs. w/c

3.5   CHARACTERISTIC STRENGTH fck

3.5.1 Criterion 1 to assess fck

3.5.2 Criterion 2 to assess fck

3.6   CONCRETE FLEXURAL AND TENSILE STRENGTH

MODULE 4

        Elastic Properties

4.1   ELASTIC MODULUS AS A FUNCTION OF THE COMPRESSIVE STRENGTH

4.2   APPROXIMATION IN THE EQUATION RELATING E WITH fcm

MODULE 5

        Chemical Properties

5.1   CONCRETE DURABILITY

5.2   PERMEABILITY COEFFICIENT OF CONCRETE

5.3   EXPOSURE CLASSES

5.3.1 Exposure Class XC: corrosion promoted by carbonation

5.3.2 Exposure Class XD: corrosion promoted by chlorides other than those from sea water

5.3.3 Exposure Class XS: corrosion of reinforcements by chlorides from sea water

5.3.4 Exposure Class XF: corrosion exposed to freezing-thawing cycles

5.3.5 Exposure Class XA: concrete in natural soils

5.3.6 Exposure Class XA: concrete structures exposed to aggressive waters

MODULE 6

        Drying Shrinkage Properties

6.1   CONCRETE DRYING SHRINKAGE

6.2   THE SHRINKAGE DEPENDS ON THE TIME

6.3   THE SHRINKAGE DEPENDS ON THE ENVIRONMENTAL HUMIDITY

6.4   THE SHRINKAGE DEPENDS ON THE FICTITIOUS THICKNESS

6.5   THE SHRINKAGE DEPENDS ON THE METALLIC REINFORCEMENTS

6.6   THE SHRINKAGE DEPENDS ON THE ELASTIC MODULUS OF THE AGGREGATE

6.7   DRYING SHRINKAGE OF A STRUCTURE FROM THE CONCRETE COMPOSITION DERIVED FROM fck, SLUMP, CEMENT
          TYPE AND Dmax OF THE AGGREGATE

6.8   CHECKING OF A DRYING SHRINKAGE PRESCRIPTION

6.9   HOW TO DESIGN THE CONCRETE MIXTURE FROM DRYING SHRINKAGE REQUIREMENTS

MODULE 7

        Creep Properties

7.1   DEFORMATION DUE TO SHRINKAGE, ELASTIC STRAIN AND CREEP

7.2   ESTIMATION OF CREEP

7.3   CREEP DEPENDS ON THE RELATIVE HUMIDITY OF THE ENVIRONMENT

7.4   CREEP DEPENDS ON THE CURING TIME AND CEMENT STRENGTH CLASS

7.5   CREEP DEPENDS ON THE CONCRETE COMPOSITION

7.6   CREEP DEPENDS ON THE THICKNESS OF THE CONCRETE STRUCTURE

7.7   CREEP DEPENDS ON THE TIME OF LOADING

7.8   CREEP DEPENDS ON THE ELASTIC MODULUS OF THE AGGREGATE

7.9   HOW TO ESTIMATE CREEP FROM CONCRETE REQUIREMENTS AND MATERIALS CHARACTERISTICS

7.10 CONCRETE COMPOSITION AS A FUNCTION OF A GIVEN CREEP

MODULE 8

        Thermal Properties

8      CONCRETE THERMAL PROPERTIES

8.1   THERMAL DILATATION COEFFICIENT

8.2   THERMAL CONCRETE CONDUCTIVITY

8.3   CONCRETE THERMAL DIFFUSIVITY

8.4   CONCRETE SPECIFIC HEAT

8.5   HEAT OF CEMENT HYDRATION

8.6   TEMPERATURE OF THE CONCRETE JUST AFTER MIXING

8.7   CONCRETE TEMPERATURE AFTER PLACEMENT AND THERMAL GRADIENTS

8.7.1 Thermal gradient and risk of cracking

8.7.2 Maximum concrete temperature due to heat of hydration

8.8   STEAM CURING OF CONCRETE

8.8.1 Correlation between the strength of the steam-cured concrete and 28-day compressive strength at
                   20°C

8.8.1.1 Strength of steam cured concrete: CEM 42.5 - Tmax= 50°C

8.8.1.2 Strength of steam cured concrete: CEM 42.5 - Tmax= 65°C

8.8.1.3 Strength of steam cured concrete: CEM 42.5 - Tmax= 80°C

8.8.1.4 Strength of steam cured concrete: CEM 52.5 - Tmax= 50°C

8.8.1.5 Strength of steam cured concrete: CEM 52.5 - Tmax= 65°C

8.8.1.6 Strength of steam cured concrete: CEM 52.5 - Tmax= 80°C

8.8.1.7 Correlation between fcmst and f’cm28

8.8.2 Concrete composition based on: fcu/ck , fcms , slump, Dmax and tc

MODULE 9

        Aggregate size distribution

9.1   PARTICLE SIZE DISTRIBUTION

9.2   IDEAL PARTICLE SIZE DISTRIBUTION OF THE SOLIDS IN CONCRETE

9.2.1 Comparison of Bolomey Vs Füller equations

9.3   PARTICLE SIZE DISTRIBUTION OF AGGREGATES

9.3.1 Influence of Dmax on the Füller curve

9.3.2 Influence of the cement content on the Bolomey equation

9.4   IDEAL AND OPTIMAL PARTICLE SIZE DISTRIBUTION OF THE AGGREGATE

9.4.1 Graphical method to combine available aggregates

9.4.2 Numerical method to combine aggregates

9.4.2.1 Numerical method to combine aggregates to reproduce a Bolomey curve (Vincenzo Maniscalco
                               Method)

             9.4.2.1.1 Bolomey with AB = 8

             9.4.2.1.2 Bolomey with AB = 10

             9.4.2.1.3 Bolomey with AB = 12

             9.4.2.1.4 Bolomey with AB = 14

9.4.2.2 Examples of combination of aggregates according to the Maniscalco Method

             9.4.2.2.1 Example of combination of two aggregates

             9.4.2.2.2 Example of combination of three aggregates

             9.4.2.2.3 Example of combinatio of five aggregates

EXERCISES