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Internal Curing Using Prewetted Lightweight Aggregates Improving Concrete Durability and Sustainability Using Internal Curing Keith McCabe Presented to: ACI Pittsburgh Haydite December 11, 2013 DiGeronimo Aggregates Sustainability Is

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SLIDE 1

Internal Curing

Using Prewetted Lightweight Aggregates

Presented to: ACI Pittsburgh December 11, 2013 Keith McCabe Haydite DiGeronimo Aggregates

Improving Concrete Durability and Sustainability Using Internal Curing

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SLIDE 2

Sustainability Is…

  • Longevity… longer lasting is usually better.
  • Balance…social, economical and

environmental issues

  • Planning… building a project right or is it more

important to build the right project

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SLIDE 3

Sustainability of Infrastructure

  • Effect on our economy
  • As population increases infrastructure needs

increase

  • Average age of bridges is 43 years*
  • More than 26%, or one in four, of the nation’s

bridges are either structurally deficient or functionally obsolete*

  • How do we improve performance
  • How do we improve sustainability

*ASCE Infrastructure Report Card 2009

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SLIDE 4

Bridges

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SLIDE 5

What is Sustainability? The capacity to endure

– Wikipedia

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SLIDE 6

Improve Sustainability of Concrete

  • Increase service life
  • Improve durability
  • Reduce cracking
  • Reduce chloride ingress
  • Increase use of SCMs
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SLIDE 7
  • 2003 FHWA Nationwide HPC survey – Most

Common Pavement Distresses

– Early-age deck cracking (57% responses were a 4

  • r 5=often)

– Corrosion (42% - definitely linked to cracking) – Cracking of girders, etc. (31%) – Others (sulfate attack, ASR, F/T, overload, poor construction quality were all below 25% level)

HPC Survey

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SLIDE 8

Internal Curing

  • Internal curing refers to the process where

increased hydration of cement occurs because of the availability of additional internal water that is not part of the mixing water.

  • Typically concrete has been cured from the
  • utside in; IC is curing from the inside out.

Internal water is supplied via internal reservoirs found in ESCS prewetted lightweight fine aggregates.

  • IC is based on simple, sound fundamental

principles

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SLIDE 9

Why we need Internal Curing

  • In HPC it is not easy to provide curing water

from the top surface at the rate that is required to satisfy the ongoing chemical shrinkage, due to the low permeability of the concrete

  • Recent research shows that IC provides

benefits in even moderate w/c mixtures

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SLIDE 10

Historical LWC Structures

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SLIDE 11

Pantheon in Rome – 126 AD

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SLIDE 12

Pantheon

Lightweight concrete dome. Romans hauled LWA 35 mi with horses…

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SLIDE 13

Southwestern Bell Building 13th & Oak, Kansas City MO 1929 - First high rise building using “Haydite” lightweight aggregate

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SLIDE 14

Lightweight Concrete Ship

USS Selma, 1919

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SLIDE 15

Sister Ship at Powell River, BC Canada

90 Years in Sea Water

Design 5000 psi, 106 pcf, Current strength 8700 psi

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SLIDE 16

Hibernia

Offshore Platform

  • St. John’s

Newfound land

1990+ IC a side benefit

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SLIDE 17

Internally Cured 126-155 pcf 10,000 -13,000 psi

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SLIDE 18

Hibernia

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SLIDE 19

Internal Curing Offers Benefits of

  • improved hydration,
  • reduced chloride ingress
  • reduced early age cracking

– All of which helps extend the service life of concrete

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SLIDE 20

More durable and less permeable concrete –

  • Improved Hydration and SCM Reaction Significantly Reduces

Concrete Porosity

  • Denser and more homogeneous interfacial transition zone

(ITZ) between lightweight aggregates and hydrating cement paste

  • Reduced Early Age and Long Term Shrinkage Cracking

Internal Curing Benefits

Better Sustainability. Lower Life Cycle Cost.

Bentz & Weiss (2011), Cusson (2010)

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SLIDE 21

Internal Curing Using Prewetted Lightweight Aggregate

  • From extensive lab research to full scale projects
  • Use fine aggregate to distribute water
  • Helps satisfy increased water demand from SCM
  • Works even at moderate 0.40 – 0.48 w/cm
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SLIDE 22

Internal Curing Using Prewetted Lightweight Aggregate

  • Benefits

– Less shrinkage, less cracking – Improved transport

  • Lower water absorption
  • Lower chloride permeability & penetration

– More hydration & SCM reaction

  • Less cement or more strength
  • Result

– More durable structures achieving extended service life

  • Improved Economics
  • Increased Sustainability
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SLIDE 23

Basics of IC - Aggregate

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SLIDE 24

First the LWA is Prewetted

  • Done by sprinkling, soaking, vacuum saturation or

thermal quenching

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SLIDE 25

Aggregate Requirements for IC

  • Aggregate needs to be able to hold sufficient

amount of absorbed water

  • Aggregate should not adversely effect the

quality of concrete

  • Aggregate needs to hold the water until

needed and not effect w/c ratio

  • Aggregate should give up water at high RH

(desorption)

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SLIDE 26

Prewetting Aggregate With Sprinklers

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SLIDE 27

6 12 18 24 30 36 42 48 Elapsed time (h) 0.0 0.2 0.4 0.6 0.8 1.0 1.2 Normalized water absorption (Mass of water/24h absorption)

Stalite Utelite Slag TXI - Boulder TXI - Streetman Norlite Buildex Solite Haydite

Castro (2011)

LWA Absorption Graphs

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SLIDE 28

Castro (2011)

Virtually all moisture available at 94% RH w/ ESCS lightweight aggregate

Typical Desorption for LWA

LWA Desorption Graph

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SLIDE 29

Blue-ink corona in cement matrix around prewetted LWA

Prewetted Lightweight Aggregate Corona: 1 mm after 1 week

Visualization of Water Transport

Cement Matrix

w/c = 0.37 Higher w/c Enlarges the Corona to 2-4+ mm

Lura (2003)

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SLIDE 30

Coarse LWA Equal Mass

  • f Fine LWA

Henkensiefken (2008)

IC Water Distribution Using Prewetted LWA

It’s All About Water Distribution

  • White = ‘thirsty’ paste
  • Blue = ‘happy’ hydrated paste
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SLIDE 31

3 x 3 mm (1/8”)

IC Water Distribution Using Prewetted LWA

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SLIDE 32

Yellow – Saturated LWA Red – Normal weight sand Blues – Pastes within various distances of an LWA

10 mm by 10 mm

IC Water Distribution Using Prewetted LWA

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SLIDE 33
  • Use fine

aggregate to distribute water

  • Help satisfy

increased water demand from SCM’s

  • Works even at

moderate 0.40 – 0.48 w/cm

IC Water Distribution Using Prewetted LWA

Bentz & Weiss (2011)

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SLIDE 34

Basics of IC - Concrete

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SLIDE 35

Scanning Electron Microscope Observations:

  • Fewer and smaller un-hydrated cement particles

(indicating enhanced hydration)

  • Fewer and smaller empty pores (indicating less self-desiccation)
  • Denser and more homogeneous interfacial transition zone (ITZ)

between lightweight aggregates and hydrating cement paste

Improved Cement Paste Microstructure

Bentz & Weiss (2011)

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SLIDE 36

RH Measurements - Without IC

24 48 72 96 120 144 168

Time (h)

80 85 90 95 100

Relative Humidity (%)

Mortar wc = 0.45 Mortar wc = 0.42 Mortar wc = 0.39 Mortar wc = 0.36 Mortar wc = 0.33 Mortar wc = 0.30

Castro (2011)

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SLIDE 37

RH Measurements - With IC

24 48 72 96 120 144 168

Time (h)

80 85 90 95 100

Relative Humidity (%)

LWA Mortar wc = 0.45 LWA Mortar wc = 0.42 LWA Mortar wc = 0.39 LWA Mortar wc = 0.36 LWA Mortar wc = 0.33 LWA Mortar wc = 0.30

Castro (2011)

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SLIDE 38

Espinoza-Hajazin (2010)

Internal Curing Increases Hydration

Degree of hydration of cement @ 90 days, cured @ 50% RH

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SLIDE 39

Sealed Curing

Higher Compressive Strength

Portland Cement Mortar @ 0.30 & 0.50 w/c

50% RH Curing

Golias (2010)

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SLIDE 40

Schlitter (2010)

Large Scale Testing

Purdue University

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SLIDE 41

Test Slabs 15’ long with end restraint. 0.30 w/c Curing: 2 days sealed, then 730 F @ 50% RH Schlitter (2010)

Large Scale Testing

Purdue University

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SLIDE 42

Plain Concrete 0.6 mm wide crack

  • bserved @ 12 days

IC Concrete 0.4 mm wide crack

  • bserved @ 43 days

Large Scale Testing

Purdue University

Schlitter (2010)

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SLIDE 43

Cracking Tendency of Lightweight Concrete

Auburn University

  • Can you get too much IC ?
  • Studied 3 LWA (shale, clay, slate), with

summer (95o) and fall (73o) curing conditions (total 20 mixes)

– control – IC, fine LWA – LWC, coarse LWA – ALWA, all fine and coarse aggregate was LWA

Byard (2010)

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SLIDE 44

Auburn Mixture Designs (w/c .42)

Item CTRL IC LWC ALWC

Water 260 260 276 276 Cement 620 620 658 568 NW C agg 1761 1761 LW C agg 933 948 NW Sand 1210 878 1354 LW F agg 230 908

Byard (2010)

Cracking Tendency of Lightweight Concrete

Auburn University

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SLIDE 45

Less Shrinkage; Less Cracking

Byard (2010)

Cracking Tendency of Lightweight Concrete

Auburn University

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SLIDE 46

20 40 60 80

Time to Cracking, hours

Control IC

Summer (95o ) curing temp. profile for expanded shale IC mix Byard (2010)

Cracking Tendency of Lightweight Concrete

Auburn University

Delayed Cracking

Cracking Tendency of Lightweight Concrete – Auburn University

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SLIDE 47
  • 10 concretes (w/c .40 .425 .450 .475 .50)
  • Drying conditions, strip 24h, 23oc, 50% RH
  • Mixtures with IC exhibit average of

– 16% better hydration, – 19% higher compressive strength, and – 30% lower permeability

  • IC very useful under poor curing conditions.

Espinoza-Hajazin (2010)

Chloride Permeability

at Higher W/C and 50% RH Cure

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SLIDE 48

Espinoza-Hajazin (2010)

Lower Chloride Permeability

Chloride ion permeability @ 90 days, cured @ 50% RH

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SLIDE 49

Reduced Chloride Ingress

2 4 6 8 28 d 56 d 180 d Exposure to Cl- (d) Penetration depth (mm)

Control IC

Bentz (2008)

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SLIDE 50
  • Silver Creek Overpass, UT
  • LWC Deck - Built in 1968
  • Chloride content after

23½ years in service

Reduced Chloride Ingress

Note: LWC not IC normal weight

ESCSI (2001)

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SLIDE 51

Lower Conductivity

Reduced 66% at 1 Year at w/c 0.42

Castro (2011) (%) Saturated Condition

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SLIDE 52

@ 7 days @ 1 year

Lower Conductivity

Reduced 66% at 1 Year at w/c 0.42

Unsaturated Condition Castro (2011)

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SLIDE 53

Plastic Shrinkage Cracking with IC

  • IC reduces the

width of the crack

  • Can prevent

cracking from

  • ccurring all

together

0.0 0.2 0.4 0.6 0.8 1.0

Crack Width (mm)

10 20 30 40 50 60 70 80 90 100

Cumulative Probability (%)

0.0%k 6.0%k 10.0%k 18.0%k

Henkensiefken (2010)

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SLIDE 54

Effect on Modulus of Elasticity

LWA Replacement lbs/cy kg/m3 GPa

Normal weight (4.78)

59 119 178 41.4 34.5 27.6 100 200 300 6 5.5 5 4.5 4 NIST (needs details)

106 psi

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SLIDE 55

Reduced Curling & Warping

Wei (2008)

Wet base, 7 day cure then 73oF @ 50% RH on slab surface

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SLIDE 56

Mixture Design & Specification

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SLIDE 57

IC Mixture Design Basics

  • How much IC water is needed
  • LWA absorption
  • LWA rate of desorption
  • Total aggregate grading of the mixture
  • Size of the IC aggregate (fines or intermediate)
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SLIDE 58

Typically replace ~400 lbs of concrete sand with an equal absolute volume of lightweight fines

How Much LWA is Needed for IC

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SLIDE 59

Simple IC Mixture Design

  • Need 7 lbs of IC water per 100 lbs of cementitious
  • 600 lbs cementitious = 42 lbs of IC water
  • Assume 18% LWA absorption in the field
  • Assume LWA at 55 lbs/cf
  • 55 x .18 = 9.9 lb/cf water at 90% desorption 8.9
  • Need 42 lbs IC water / 8.9 = 4.7 cf of LWA
  • 4.7 cf x 55 lb/cf = 259 lbs of LWA aggregate
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SLIDE 60

Batching Prewetted LWA

  • Calculate absorbed and surface moisture
  • Utilize paper towel test, NY 703-19E Moisture

Content of Lightweight Fine Aggregate (Aug 2008) on ESCSI Website

  • Adjust pull weights by absorbed moisture only
  • Absorbed water not included in w/c
  • Reduce mix water by surface moisture
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SLIDE 61

Mixture Proportions of the Fine Aggregate In a Yard of Concrete

Natural Sand Replacement

Replace about 30% of the Fine LWA

Natural Sand LWA

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SLIDE 62

NY State DOT Specifications

  • Proper amount of water
  • 30% replacement of fine aggregate
  • Minimum 15% absorbed moisture
  • Place under sprinkler for minimum of 48 hours
  • Allow stockpiles to drain for 12 to 15 hours

immediately prior to use

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SLIDE 63
  • Calculate absorbed and surface moisture
  • Utilize paper towel test
  • Adjust pull weights by absorbed moisture only
  • Absorbed water does not effect w/c
  • Reduce mix water by surface moisture

NY State DOT Specifications

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SLIDE 64

Projects / Case Studies IC

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SLIDE 65

Real World IC Projects

  • NY State
  • Texas

Visual inspections At 6 months one crack At 5.5 years minuscule plastic or drying shrinkage cracks UP RR Intermodal Facility Constructed 2005 250,000 yd3 IC project low slump pavement

Paving in Texas

Bridges in New York State

16 built or under construction

Paving in Texas

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SLIDE 66

Internal Curing vs. No Internal Curing – 1 day after placement

Highlands Ranch, CO – 92oF ambient, 20% RH. (no conventional curing) Internal Curing No Internal Curing

Water Tank - Denver, CO

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SLIDE 67

Water Tank - Denver, CO

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SLIDE 68

Indiana DOT Test in 2010

  • Internally cured concrete

looks the same

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SLIDE 69

Indiana DOT Test in 2010

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SLIDE 70

Indiana DOT Test

Conventional Deck @ 2 Months

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SLIDE 71

Indiana DOT Test

Internal Curing Deck @ 1 Year– No Cracks

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SLIDE 72

I190/I290 Interchange

Buffalo, NY

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SLIDE 73

Interstate 81 - Whitney Point, NY

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SLIDE 74

NY 353 - Salamanca, NY

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SLIDE 75

Case Studies - New York State

Spencer and Court Street Overpass, Syracuse, NY

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SLIDE 76

Court Street Overpass I-81

September 2009

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SLIDE 77

HPC Mixture Design (w/cm 0.42)

Spencer and Court Street Overpass, Syracuse, NY

Batch weights in pounds

Spencer St Standard Mix Court St IC mix Cement 500 500 Fly ASH 135 135 Microsilica 40 40 Fine LWA 196 Fine Aggregate 1130 782 Coarse Aggregate 1720 1720 Water 270 262

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SLIDE 78

HPC Mixture Design (w/cm 0.42)

Spencer Street Overpass, Syracuse, NY

Batch weights in pounds

Spencer St Standard Mix Cement 500 Fly ASH 135 Microsilica 40 Fine LWA Fine Aggregate 1130 Coarse Aggregate 1720 Water 270

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SLIDE 79

HPC – IC Mixture Design (w/cm 0.42)

Court Street Overpass, Syracuse, NY

Batch weights in pounds

Court St IC mix Cement 500 Fly ASH 135 Microsilica 40 Fine LWA 196 Fine Aggregate 782 Coarse Aggregate 1720 Water 262

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SLIDE 80

IC Aggregate Grading

5 10 15 20 25 30 35 40 45 50 1/2 NO.4 NO.16 NO.50 PAN % Retained Screen Size IC Fine Aggregate

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SLIDE 81

Court Street Bridge

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SLIDE 82

Court Street Bridge

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SLIDE 83

Court Street Bridge

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SLIDE 84

Syracuse, NY Bridge Comparison

Bridge Projects Concrete Type 7 day Compressive Strength (MPa) 14 day Compressive Strength (MPa) 21 day Compressive Strength (MPa) 28 day Compressive Strength (MPa) Spencer and Butternut Street HPC 32.6 40.8 41.9 43.5 Court Street HPC-IC 33.5 42.9 45.3 48.1 Percent Improvement

2.8% 5.1% 8.1% 10.6%

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SLIDE 85

Bartell Road Overpass I-81

Cicero, NY

May 2010

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SLIDE 86

Bartell Road Overpass I-81

Cicero, NY

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SLIDE 87

Bartell Road Overpass I-81

Cicero, NY

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SLIDE 88

HPC – IC Mixture Design

Bartell Road Cicero, NY

Batch weights in pounds

Cement – Type 1 506 Fly ASH 135 Microsilica 42 Fine Aggregate – Natural Sand 797 Fine Aggregate – Expanded Shale 194 Coarse Aggregate -1& 2 blend 1726 Water 273 w/cm 0.40

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SLIDE 89

Bartell Road Bridge Comparison

7 day 14 day 21 day 28 day Compressive Compressive Compressive Compressive Concrete Strength Strength Strength Strength Type (MPa) (MPa) (MPa) (MPa) Bartell Road HPC 22.2 17.3

  • 30.2

Bartell Road HPC-IC 21.0 25.9 29.4 34.8 Percent Improvement

  • 5.4%

49.7%

  • 15.2%

Source: NYSDOT

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SLIDE 90

NYSDOT Study - Variety of Conditions

  • Bridge type
  • Number of spans
  • Regions
  • Climates
  • De-icing chemicals
  • Traffic loading
  • Time when poured
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SLIDE 91

NY Projects Built or Under Construction

  • NY Route 9W over Vineyard Avenue
  • NY Route 96 over Owego Creek
  • Interstate 81 at Whitney Point Southbound
  • Interstate 81 at Whitney Point Northbound
  • Court Street over Interstate 81
  • Bartell Road over Interstate 81
  • Interstate 86 over NY Route 415
  • Interstate 84 over Route 6
  • Interstate 290 Ramp B over Interstate 190

Continues…

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SLIDE 92
  • Interstate 81 over East Hill Road
  • NY Route 17 Exit 90 Ramp over East Branch Delaware

River

  • NY Route 38B over Crocker Creek
  • NY Route 353 over Allegheny River
  • Interstate 290 Ramp D Over Interstate 190
  • Interstate 87 over Route 9 and Trout Brook
  • Interstate 81 Connectors near Fort Drum

NY Projects Built or Under Construction

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SLIDE 93

Highway 121 Mainline Paving

  • State Highway 121, Dallas, Texas
  • 1300 cubic yards, 5 miles
  • Continuously Reinforced Concrete Pavement

(CRCP)

  • November 16, 2006
  • Class P (3500 psi or 570 psi flex at 7d)

Friggle & Reeves (2008)

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SLIDE 94

Mixture Used 300 lbs (5 cu ft bulk) Intermediate LWA per Cu Yd Concrete

Highway 121 Mainline Paving

Aggregate Grading Friggle & Reeves (2008)

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SLIDE 95

4000 psi @ 4 days 6000+ psi @ 28 days

Highway 121 Mainline Paving

Friggle & Reeves (2008)

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SLIDE 96

500 ft section, no joints Survey: 2/1 and 9/11/2007 Survey: 76d old, Average IC Crack Spacing: 31ft Survey: 10m old, Number of cracks, IC 21 vs. 52 control

Highway 121 Mainline Paving

Crack Spacing of IC section

Friggle & Reeves (2008)

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SLIDE 97

IC

0.10

Crack width (mm)

LWA Section Control Section

Crack distribution %

Less than 0.10 0.15 90% 60% 30% 10%

Highway 121 Mainline Paving

Crack Width (% of total at 10 months old)

Friggle & Reeves (2008)

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SLIDE 98

Union Pacific Intermodal Facility

Hutchins, Texas January 2005

250,000 yd3 IC project low slump pavement Visual inspection at 6 months found one crack At 6 years minuscule plastic or drying shrinkage cracks

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SLIDE 99

Union Pacific Intermodal Facility

Hutchins, Texas January 2005

  • Low Slump IC Mixtures
  • Enhanced Workability
  • Better Consolidation
  • Flexural Strengths 650 – 700 psi @ 28 days
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SLIDE 100

Better Pavements in Texas

  • Since 2003, TXI placed 2,000,000 cy IC mixtures

with1.3 million in low slump pavements

  • IC Mitigates or eliminates plastic and drying

shrinkage cracks

  • Average 1000 psi strength gain with IC
  • 5 bulk cu ft of IC LWA reduces weight by 200 lbs/cy

– 10yd load = 2000 lbs or .5 cy per load or – 5% fewer truck loads

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SLIDE 101

Life Cycle Cost Analysis

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SLIDE 102

(8 in) Cusson (2010)

Life Cycle Cost Analysis

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SLIDE 103

National Research Council Canada Study Compared Three Concrete Bridge Deck Options: NC =

Normal Concrete with No Supplementary Cementitious Materials (SCM)

HPC =

High Performance Concrete with 25% SCM

HPC-IC = High Performance Concrete with 25% SCM

and Internal Curing

Cusson (2010)

Life Cycle Cost Analysis

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SLIDE 104

Initial Water Cement W/C SCM LWA Deck Option Cracking (kg/cu m) (kg/cu m) Ratio (%) (kg/cu m) NC No 140 350 0.40 HPC Yes 160 450 0.36 25 HPC-IC No 160 450 0.36 25 200 Cusson (2010)

Life Cycle Cost Analysis

Mixture Designs

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SLIDE 105

HPC Concrete HPC-IC Concrete Improve ment Property w/c = 0.35 w/c = 0.35 (%) IC water provided (kg/kg) 0.075 C-S-H content at 28 days (Hydration) 10.2 12.3 21 Compressive Strength at 7 days (MPa) 45 50 11 Compressive Strength at 28 days (MPa) 60 65 8 Water Permeability (m/s) 2.10E-11 1.70E-11 19 Chloride Permeability (coulomb) 553 415 25 Freeze/Thaw Resistance (% mass loss) 0.60 0.26 56 less Salt Scaling Resistance (% mass loss) 0.46 0.30 35 less Cusson (2010)

Life Cycle Cost Analysis

Impact of IC on Mixture Properties

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SLIDE 106

10 20 30 40 50 60 70 NC HPC HPC-IC

23 years 40 years 63 years

Cusson (2010)

Life Cycle Cost Analysis

Service Life Predictions

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SLIDE 107

Cusson (2010)

Life Cycle Cost Analysis

Service Life Prediction

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SLIDE 108

Cusson (2010)

Life Cycle Cost Analysis

Initial vs. Life Cycle Costs

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SLIDE 109

+18 yr $+25% +23 yr +$4%

Cusson (2010)

Life Cycle Cost Analysis

Initial vs. Life Cycle Costs

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SLIDE 110

References

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SLIDE 111

References

Byard, B. & Schindler, A. (2010). Cracking Tendency of Lightweight Concrete, Research Report. Auburn University: Highway Research Center. Bentz, D., & Snyder, K. (1999). Protected Paste Volume in Concrete: Extension to Internal Curing using Saturated Lightweight Fine

  • Aggregate. Cement and Concrete Research , 29 (11), 1863-1867.

Bentz, D., Lura, P., & Roberts, J. (2005). Mixture Proportioning for Internal Curing. Concrete International , 27 (2), 35-40. Bentz, D., Halleck, P., Grader, A., & Roberts, J. (2006). Water Movement during Internal Curing: Direct Observation using X-ray

  • Microtomography. Concrete International , 28 (10), 39-45.

Bentz, Dale (2006b) Internal Curing – Questions and Answers, Mid-Atlantic Region Quality Assurance Workshop presentation, Feb 2006 http://ciks.cbt.nist.gov/~bentz/ICqanda.ppt Bentz, D (2008), Curing Concrete from the Inside Out (Internal Curing), May 2008 concrete Bridge Workshop, St. Louis, http://ciks.cbt.nist.gov/~bentz/Bridgeworkshop2008.ppt Bentz, D & Weiss, J., (2011) Internal Curing: A 2010 State-of-the- Art Review, National Institute of Standards and Technology NIISTIR 7765, Feb 2011 Bentz (2012) Web Link at NIST: http://ciks.cbt.nist.gov/~bentz/ICnomographEnglishunits.pdf

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SLIDE 112

Browning, JoAnn, Darwin, David, Reynolds, Diane, Pendergrass, Benjamin, Lightweight Aggregate as Internal Curing Agent to Limit Concrete Shrinkage, ACI Materials Journal, V. 108, No. 6, November-December 2011. Castro, J. (2011). Moisture Transport in Cement-Based Materials: Application to Transport Tests and Internal Curing, Ph.D. Thesis. West Lafayette: Purdue University. Cusson, D., Lounis, Z., & Daigle, L. (2010). Benefits of Internal Curing on Service Life and Life-Cycle Cost of High-Performance Concrete Bridge Decks – A Case Study. Cement and Concrete Composites, 32. ESCSI (2001) Back-Up Statistics to Building Bridges and Marine Structures with Structural Lightweight Aggregate Concrete, Information Sheet 470.4, Expanded Shale, Clay and Slate Institute, 35 East Wacker Dr., Suite 850, Chicago, IL 60601 Espinoza-Hajazin, G., & Lopez, M. (2010) Extending Internal Curing To Concrete Mixtures With W/C Higher Than 0.42. Construction & Building Materials, Elsevier Ltd. Friggle, T., and Reeves, D., (2008) Internal Curing of Concrete Paving Laboratory and Field Experiences, ACI SP-256, Eds. D. Bentz and B. Mohr, American Concrete Institute, 71-80, CD-Rom, 2008. Golias, M. (2010). The Use of Soy Methyl Ester-Polystyrene Sealants and Internal Curing to Enhance Concrete Durability, M.S.

  • Thesis. West Lafayette: Purdue University.

References

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SLIDE 113

Henkensiefken, R. (2008). Volume Change and Cracking in Internally Cured Mixtures Made with Saturated Lightweight Aggregate Under Sealed and Drying Conditions, Presented at ACI Fall Convention, St. Louis, MO. Henkensiefken, R., et al. (2008b). Reducing Restrained Shrinkage Cracking in Concrete: Examining the behavior of self-curing concrete made using different volumes of saturated lightweight aggregate. National Concrete Bridge Conference, St. Louis, MO. Henkensiefken, R., Bentz, D., Nantung, T., & Weiss, J. (2009). Volume Change and Cracking in Internally Cured Mixtures Made with Saturated Lightweight Aggregates under Sealed and Unsealed Conditions. Cement and Concrete Composites , 31 (7), 426-437. Henkensiefken, R., Briatka, P., Bentz, D., Nantung, T., & Weiss, J. (2010). Plastic Shrinkage Cracking in Internally Cured Mixtures (Made with Pre-wetted Lightweight Aggregate.) Concrete International , 32 (2), 49-54. Lura, P. (2003) Autogenous Deformation and Internal Curing of Concrete, Ph.D. Thesis, Delft University, Delft, The Netherlands Schlitter, J., Henkensiefken, R., Castro, J., Raoufi, K., Weiss, J., & Nantung, T. (2010). Development of Internally Cured Concrete for Increased Service Life. Joint Transportation Research Program. West Lafayette: Purdue University. Wei, Y., & Hansen, W. (2008). Pre-soaked Lightweight Fine Aggregates as Additives for Internal Curing in Concrete. In D. Bentz, & B. Mohr (Ed.), Internal Curing of High-Performance Concretes: Laboratory and Field Experiences, ACI SP 256, American Concrete Institute Farmington Hills MI (pp. 35-44).

References

Page 3 of 3

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SLIDE 114

Researchers

Dale Bentz

Chemical Engineer National Institute of Standards & Technology 100 Bureau Drive Stop 8615 Gaitherburg, MD 20899 (301) 975-5865 dale.bentz@nist.gov http://concrete.nist.gov/bentz

Jason Weiss

Professor Purdue University – School of Civil Engineering 550 Stadium Mall Drive West Lafayette, IN 47907 (765) 494-2215 wjweiss@purdue.edu http://cobweb.ecn.purdue.edu/~wjweiss

Anton Schindler

HRC Director/Associate Professor Auburn University 238E Harbert Engineering Center Auburn, AL 36849 (334) 844-6263

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SLIDE 115

Wrap Up / Summary / Conclusions

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SLIDE 116

Conclusions

  • Prewetted LWA fines can be used to

improve concrete properties

  • IC material should have proper moisture
  • IC material should have proper desorption

characteristics

  • Addition of IC materials do not affect the

finishability of concrete

  • IC will improve the durability of HPC
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SLIDE 117

More durable and less permeable concrete –

  • Improved Hydration and SCM Reaction Significantly Reduces

Concrete Porosity

  • Denser and more homogeneous interfacial transition zone

(ITZ) between lightweight aggregates and hydrating cement paste

  • Reduced Early Age and Long Term Shrinkage Cracking

In Summary

Better Sustainability. Lower Life Cycle Cost.

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SLIDE 118

In Summary – Other Benefits

  • Enables ‘greener’ concrete as OPC can be replaced

(limestone, ash, slag)

  • Longer life and use of SCMs lower carbon footprint
  • More efficient use of cement and SCM
  • Increase strength
  • Increases ‘reserve capacity’ for temperature effects

during construction

  • Lower modulus of elasticity…less cracks
  • Helps offset poor curing – improves good curing
  • Reduced curling / warping
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SLIDE 119

In Summary - Sustainability

  • Taking a holistic approach from the beginning.

Plan the right project and design it right

  • Think long term
  • We can’t solve our problems with the same

mindset that we created them

  • We must be more aware of the way we relate

to each other, our environment and the way we do business

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SLIDE 120

www.escsi.org

Questions?

Keith McCabe DiGeronimo Aggregates 216-524-2950 office 216-536-3834 cell www.digagg.com