1. The document discusses various types of concrete deterioration including acidic water, carbonation, chloride-induced corrosion, sulfate attack, and alkali–aggregate reaction (AAR). It provides the mechanisms and recommendations for preventing each type. 2. Carbonation occurs via the reaction of calcium hydroxide in cement paste with carbon dioxide in the atmosphere, lowering the pH and favoring reinforcement corrosion. Factors like humidity, temperature, and CO2 concentration affect carbonation. 3. Sulfate attack can be external, causing ettringite or thaumasite, or internal, causing secondary gypsum or delayed ettringite formation. Recommendations include low water-cement ratio concrete and use

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Holcim Group Support Course for Cement Applications 2008
Concrete Deterioration – Type and Mechanism
 Type
- Acidic water
- Carbonation
- Chloride induces corrosion of the reinforcement
- Sufate atact – DEF – thaumasite
- AAR

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Holcim Group Support Course for Cement Applications 2008
Acidic water - Mechanism
 Disolution of SH
- without reaction
- with reaction – soluble Salts ( CaCl2, Ca(NO3)2
 Recommendation
- Stabile aggregates
- Lower w/c in concrete
- Use composite cements ( slag, FA)

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Holcim Group Support Course for Cement Applications 2008
Carbonation - Mechanism
 The carbonation - a chemical process that involves the reaction of
the calcium hydroxide from the cement paste and the CO2
from the atmosphere - modifies the pH of the concrete, favoring
the corrosion of its reinforcement.
 Factors affecting carbonation
- Humidity – 50 – 70%
- Ca(OH)2 more soluble at lower T
- Concentration of CO2 in atmosphere
Carbonation test – by Phenolphthalein Solution

4. 4
Holcim Group Support Course for Cement Applications 2008
Sulfate Attack - Mechanism
 Sulfate Attack
- External – ettringite, Thaumasite
- Internal – secondary gypsum, delayed ettringite (DEF – T of
concrete > 60 C
 Recommendation
- Low w/c in concrete
- Use composite cements –CEM II-B,CEM III
- Low contents in alkalies,C3S, SO3 and C3A

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Holcim Group Support Course for Cement Applications 2008
Chloride Attack- Mechanism
 Chloride ions can be introduced into the concrete
- Fe2+ + 2Cl- ⇒ FeCl2
- FeCl2 + 2H2O ⇒ Fe(OH)2 + 2HCl
Corrosion of reinforced steel
 Recommendation
- Low w/c in concrete
- Use composite cements –CEM II-B,CEM III

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Holcim Group Support Course for Cement Applications 2008
Freeze – Thaw Resistance
 Mechanism of frost damage
The water present in its porous can freeze:
- Hydraulic pressures
- Osmotic pressures
 The using air entraining agents – positive effect of air
bubbles
 Type of air entraining agents
 Spacing faktor as a function of total air content L<200
( distance between bubbles)

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Holcim Group Support Course for Cement Applications 2008
Key Learnings – Freeze-Thaw Resistance
 Frost Damage:
 Hydraulic Pressure: Mostly due to water expansion when freezing.
 Osmotic Pressure: Due to alkali solutions
 Air-entrined concrete is highly resistant to frost deterioration because the air bubbles leave
space for water expansion.
 This messure is even regulated in standards due to effectiveness. Space and distance
among bubbles are key factors.
 Mechanism of Air Entrainment:
 Air is generated in concrete during the mixing.
 AEA are surfactants which concentrate the air-water interface and reduce the surface
tension easing the bubble formation.
 Types of AEA:
 Wood delivered products (Vinsol and wood resin), tall oil.
 Synthetic Material (Alky-aryl sulfonates and sulfates).
 Miscellaneous (alkali/alkanolamine acid salts and animal tallows).
 Concrete design: The AEA to include in the mix depends on:
 Fineness
 Carbon Content
 Impurities
 Alkali Content
 Organic Material Content
 Loss of Ignition

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Holcim Group Support Course for Cement Applications 2008
Key Learnings_18 November: Concrete Shrinkage
Definition
 Concrete shrinkage results of the build up of tensile forces due to the formation of
water menisci within the concrete pore system (voids < 50 nm detrimental)
 Time of occurrence: critical period between 2h and 24h of fresh concrete
Types of shrinkage
 Plastic shrinkage:
 occurs when water is lost by evaporation from concrete during plastic state
 significantly developing in OPC and HPC
 Drying shrinkage:
 due to water lost from hardened concrete exposed to air with a low relative humidity
 important in OPC
 Autogenous shrinkage:
 due to concrete self desiccation (water diffusion from big capillary pores to smaller ones)
 Mainly important in low w/c concrete (HPC, OPC)
 Thermal shrinkage:
 due to concrete volume change during different phases of hydration

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Holcim Group Support Course for Cement Applications 2008
Key Learnings_18 November: Concrete Shrinkage
How to reduce potential of concrete shrinkage?
 Minimize shrinking inducing component
 Water content
 Volume of paste
 Shrinking aggregate (low E-modulus/high compressibility/high absorption/high clay
coatings)
 Use shrinkage reducing admixture (but decrease strength by 20%)
 Use shrinkage compensating admixture (but cost expensive)
 Good curing
 Adequate cement design
 MIC cement
 Entrained air binder (2-3%)
 Coarser cement
 Adequate MIC quality
 Adequate compressive strength 2d and 28d

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Holcim Group Support Course for Cement Applications 2008
High Performance Concrete
What is high performance concrete ?
High early and late strength
High E-Modulus and low creep
High workability and low permeability
Sulfate & chloride and frost, chemical resistant
Abrasion resistance
Type of concrete Time Compressive strength
Very high early
strength
4 hours >17.2 MPa
high early strength 24 hours >34.5 MPa
Very high strength 28 days >68.9 MPa
Low porosity
W/C 0.25-0.40

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Holcim Group Support Course for Cement Applications 2008
High Performance Concrete
How to achieve HPC
 Low w/c ratio
 High amount of fines smaller than 0.125 (>380kg/m3)
 Minimum 3 days curing
The paste strength is normally < aggregate strength
Selections of materials: cement, mineral components (some
limitations), coarse aggregates, fine aggregates

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Holcim Group Support Course for Cement Applications 2008
High Performance Concrete
Mix design(7 steps)
Class of resistance l ll lll lV
Compressive strength
(MPa)
50-75 75-100 100-125 125-150
W/C ratio 0.35-0.40 0.30-0.35 0.25-0.30 <0.25
Mixing water(L/m3) 150-160 140-150 130-140 <130
Tables of Mix design (Canadian experience)
Fresh properties table
Hardened properties
Table of Mix design (French experience)
Curing
Field of applications and some examples

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Holcim Group Support Course for Cement Applications 2008
Self- compacting concrete (SCC)
Why SCC?
What is SCC ?
SCC… a new generation high performance flowing concrete
Definition
“Flowable concrete that can be placed under its own weight and can fill the form without vibration
and achieve good consolidation without exhibiting any segregation nor bleeding”
Terminology
SCC, self leveling concrete (slab application-horizontal), self-placing (wall, column-vertical)
Introduction
Due to heat generation and low porosity requirements, slag and fly ash have been used to achieve
a flowable and at the same time stable concrete
First prototype
Properties

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Holcim Group Support Course for Cement Applications 2008
Self- compacting concrete (SCC)
Mix design
Requirements
Specificity of SCC
Rules
Test methods
Production and placement
Holcim in deferent countries
Performances
Marketing aspects-Benefits
Limit factors and conclusion