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2010 Concrete Sustainability Conference 1 © National Ready Mixed Concrete Association
Lightweight Aggregate g g gg gOptimizes the
Sustainability of ConcreteSustainability of Concrete
John Ries PE, FACIE d d Sh l Cl d Sl t I tit tExpanded Shale, Clay and Slate Institute
www.escsi.org
2010 Concrete Sustainability Conference 2 © National Ready Mixed Concrete Association
So what is Sustainability ?y
• It’s a design issue• Nature doesn’t have a design problem• Sustainability is just good design and
common sense
2010 Concrete Sustainability Conference 3 © National Ready Mixed Concrete Association
Design for Intended Service Life
Concrete Fails at the Crack Durability is about crack controlStart with micro cracks (Micro structure)Reducing micro-cracking Improves durability
Structural lightweight aggregate controls cracksBond between aggregate and paste (Contact Zone)Elastic compatibilityInternal curing
2010 Concrete Sustainability Conference 4 © National Ready Mixed Concrete Association
What is Lightweight Aggregate?g g gg g
• ASTM C 330 & C 331• Volcanic:
Pumice, Scoria, Tuff (Romans)M f t d• Manufactured:Blast Furnace Slag Expanded Shale Clay or Slate (1908)Expanded Shale, Clay or Slate (1908) Sintered Fly Ash
• By products of coal or coke combustionBy products of coal or coke combustionBottom ash, cinders
2010 Concrete Sustainability Conference 5 © National Ready Mixed Concrete Association
Lightweight Aggregate
isisAbout One Half theHalf the
Bulk D iDensity
2010 Concrete Sustainability Conference 6 © National Ready Mixed Concrete Association
Cost / Volume / Weight ratio
2010 Concrete Sustainability Conference 7 © National Ready Mixed Concrete Association
LWA has been used for 2000 yrsWHY ?WHY ?
• Because there is something special…• Because it makes concrete more durable…• Because it’s cost effective… • These same reasons make it sustainable….
(green material)
2010 Concrete Sustainability Conference 8 © National Ready Mixed Concrete Association
2000 yrs of Sustainabilityy y
• Roman Period used lots of LWA– Port of Cosa 273 BC (only surface abrasion)– Coliseum 75 to 80 AD (50,000 seat capacity)
Pantheon 126 AD (142 ft dome)– Pantheon 126 AD (142 ft dome)• Crushed and hauled in volcanic lava 25
miles by wagon (not the local sand ormiles by wagon (not the local sand or agg)
• Shards calcined clay vases and crushed ybrick aggregate
2010 Concrete Sustainability Conference 9 © National Ready Mixed Concrete Association
Pantheon 1884 yrs old
2010 Concrete Sustainability Conference 10 © National Ready Mixed Concrete Association
Pantheon142 ft d142 ft domewith decreasing densitydensity
Was notWas not exceeded for over 1800 yrs
2010 Concrete Sustainability Conference 11 © National Ready Mixed Concrete Association
Lightweight Concrete Ships g g p
• 14 ships built during WW1 (1918-21)– Design 5000 psi min. (Actual 5550 psi)
Tested 1953, 1979, & 1999 (8700-10,000 psi)– Density 95-106 lbs/cfDensity 95 106 lbs/cf– Hull is 4” to 5” thick– 5/8” – 3/4” of cover over rebar– Ship 7500 tons, 2660 cy, 1550 tons smooth bar
• 90 built during WW2 density (120-125) lbs/cy The largest had 140,000 ton capacity
2010 Concrete Sustainability Conference 12 © National Ready Mixed Concrete Association
U.S.S. Selma June 1919
434 ft long 43 feet wide434 ft long, 43 feet wideDraft of 26 feet, 4-5” thick, 5/8” cover
2010 Concrete Sustainability Conference 13 © National Ready Mixed Concrete Association
2010 Concrete Sustainability Conference 14 © National Ready Mixed Concrete Association
The first slump conecone
2010 Concrete Sustainability Conference 15 © National Ready Mixed Concrete Association
LIGHTWEIGHT CONCRETE SHIP PASSING UNDER LIGHTWEIGHT
CO C GCONCRETE BRIDGE 1944
14 built WW 114 built WW 190 built WW 2
104 Total Ships
2010 Concrete Sustainability Conference 16 © National Ready Mixed Concrete Association
Peralta 1920
10 Ships located at Powell River, BC Canada90 yrs in sea water, design 5000 psi 106 pcf
Current strength 8700-10,000 psi
2010 Concrete Sustainability Conference 17 © National Ready Mixed Concrete Association
80 year old Peralta with 5/8” to 3/4” coverCTL 1999 “The concrete is of exceptionally good
lit d ll i i ll t diti ”quality and overall is in excellent condition.”
2010 Concrete Sustainability Conference 18 © National Ready Mixed Concrete Association
Bond between Aggregate and Paste• Improved mechanical bond - rough surface texture
I d Ch i l b d f i li h l• Improved Chemical bond - surface is slightly pozzolanicReduces micro cracking•Reduces micro-cracking
2010 Concrete Sustainability Conference 19 © National Ready Mixed Concrete Association
ESCS LWA
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2010 Concrete Sustainability Conference 21 © National Ready Mixed Concrete Association
Normalweight concrete
2010 Concrete Sustainability Conference 22 © National Ready Mixed Concrete Association
Normalweight concrete
2010 Concrete Sustainability Conference 23 © National Ready Mixed Concrete Association
Normal weight concrete
2010 Concrete Sustainability Conference 24 © National Ready Mixed Concrete Association
Elastic Compatibility
•Modulus of elasticity of LWA is close to the modulus of the cement pastethe modulus of the cement paste•Reduces stress concentrations •Reduces microcracking•Reduces microcracking, autogenous shrinkage, and shrinkage crackingg g
2010 Concrete Sustainability Conference 25 © National Ready Mixed Concrete Association
Internal Curingg
• Process by which water is provided throughout the concrete to enhance cement hydrationthe concrete to enhance cement hydration
• Accomplished by adding saturated LWA (fines or intermediate) or super absorbent polymer material (diapers)
• Especially helpful for HPC, low w/cm ratio, improve durability longer service lifeimprove durability, longer service life
• Also works for every day concrete .45 - .55 w/cm
2010 Concrete Sustainability Conference 26 © National Ready Mixed Concrete Association
2010 Concrete Sustainability Conference 27 © National Ready Mixed Concrete Association
Absorption into Lightweight AggregateAggregate
2010 Concrete Sustainability Conference 28 © National Ready Mixed Concrete Association
Why use Internal Curing(all about the micro structure)(all about the micro structure)
• Minimizes Plastic Shrinkage Cracks• Reduces Autogeneous Shrinkage• Delays Drying Shrinkage• Mitigates Self Dessication• Mitigates Self Dessication• Mitigates micro cracks • Disconnects capillaries (chloride intrusion)p ( )• Improves the Contact Zone• Helps offset poor curing
2010 Concrete Sustainability Conference 29 © National Ready Mixed Concrete Association
Academic Studies
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2010 Concrete Sustainability Conference 30 © National Ready Mixed Concrete Association
Internal Curing Affect on ShrinkagePurdue Univ Henkenseifken et al RestrainedPurdue Univ - Henkenseifken, et al. Restrained shrinkage of sealed mortar specimens (Cracking Ring)
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Purdue Univ. Henkenseifken, et al. –(free shrinkage)( g )
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2010 Concrete Sustainability Conference 32 © National Ready Mixed Concrete Association
Deck Cracking Tests, Auburn UnivPreliminary results, 1 LWA, 2 more to testy
NWCIC SLW
ALW
Spring - 73 deg.
NWC ICNWC
Summer - 95 deg.g
2010 Concrete Sustainability Conference 33 © National Ready Mixed Concrete Association
Paveing Mixture With Internal Curing
300 lbs of LWA intermediates (# 4-16)
4000 psi at 4d4000 psi at 4d 6000+ at 28d
At 2 ½ monthsAt 2 ½ months less than ½ the cracks & smaller SH 121, Dallas, TXcracks
2010 Concrete Sustainability Conference 34 © National Ready Mixed Concrete Association
IC Benefits for Concrete PavementPavement
• Reduce number of shrinkage cracks• Reduce the width of cracks• Increase strength of the concrete• Improves durability• Increase the probability of quality
t (I th l ld IC tconcrete (In the real world IC acts as insurance)
2010 Concrete Sustainability Conference 35 © National Ready Mixed Concrete Association
Slab Curlingg
• ACI SP-256-3 Pre-soaked LWA Fines as additives for Internal Curing in Concreteadditives for Internal Curing in Concrete (Wei and Hansen, Univ. Michigan)
• w/c .35 &.45• Sand replacement of 20% and 40% by volume . • Results: “IC is effective in mitigating autogenous
shrinkage but also reduces slab uplift fromshrinkage but also reduces slab uplift from moisture warping due to drying at the top and wetting at the bottom.”
2010 Concrete Sustainability Conference 36 © National Ready Mixed Concrete Association
Resistance to Chloride Intrusion•LWA has improved resistance to chloride intrusion•Silver Creek Overpass, UT constructed in 1968constructed in 1968•Chloride content after 23½ years in service
Depth LWC Deck NWC Appr. Slab
0" to ½" 36 7 lbs / CY 20 5 lbs / CY0 to ½ 36.7 lbs / CY 20.5 lbs / CY
½" to 1" 18.0 lbs / CY 18.0 lbs / CY
1" to 1½" 7 7 lbs / CY 15 7 lbs / CY1 to 1½ 7.7 lbs / CY 15.7 lbs / CY
1½" to 2" 0.5 lbs / CY
2010 Concrete Sustainability Conference 37 © National Ready Mixed Concrete Association
LWC Deck Wear Performance
•Nickel bridge, Richmond VA•LWC deck was removed after 34 years in service•Several F/T cycles and salted regularlysalted regularly
Wear was uniform 1/8”Wear was uniform, 1/8Well over 100m crossingsNo deterioration or corrosionNo deterioration or corrosionNear perfect condition (34yr)
2010 Concrete Sustainability Conference 38 © National Ready Mixed Concrete Association
2010 Concrete Sustainability Conference 39 © National Ready Mixed Concrete Association
Optimize Bridge Design (600+ major bridges in NA)(600+ major bridges in NA)
• Wider bridge deck (additional lanes) on i ti t t l texisting structural supports
• Balance cantilever (longer on the LW side)side)
• Deck may be thicker for better drainage• More cover over reinforcement• More cover over reinforcement• Longer bridge spans, fewer bridge piers
Pier location flexibility• Pier location flexibility
2010 Concrete Sustainability Conference 40 © National Ready Mixed Concrete Association
Raftsundet Bridge, NorwayNorway
2010 Concrete Sustainability Conference 41 © National Ready Mixed Concrete Association
2010 Concrete Sustainability Conference 42 © National Ready Mixed Concrete Association
Wabash River BridgeLafayette, Indiana
2010 Concrete Sustainability Conference 43 © National Ready Mixed Concrete Association
96 girders, 175 ft long – 7.5 ft height96 tons, 7000 psi @ 5 days96 tons, 7000 psi @ 5 days17% weight reductionCost savings $1.7 m Total project $9.4 million
2010 Concrete Sustainability Conference 44 © National Ready Mixed Concrete Association
Hibernia Offshore PlatformSt. John’s Newfoundland
LWC 126-150 pcf 10-13,0000 psipsi
2010 Concrete Sustainability Conference 45 © National Ready Mixed Concrete Association
HiberniaOffshorePlatform
2010 Concrete Sustainability Conference 46 © National Ready Mixed Concrete Association
Hibernia Final1 2 million tons1.2 million tons
2010 Concrete Sustainability Conference 47 © National Ready Mixed Concrete Association
Optimize Building Designp g g
• Less weight helps sustainability• Smaller foundations, beams and columns• Reduced seismic inertia• Less overall material used• Longer spans increasing design flexibility• Better fire ratings
2010 Concrete Sustainability Conference 48 © National Ready Mixed Concrete Association
Fire Rated Steel Deck Assemblies
2010 Concrete Sustainability Conference 49 © National Ready Mixed Concrete Association
Why on Steel Decks?
• Reducing Floor Dead Load• Typical LW Concrete 20-25% Less
NW 145 – 150 lb/ft³LW 110 + 3 lb/ft³LW 110 + 3 lb/ft
• LW Concrete Floor Load 45 – 50% Less2 hour fire rating @ 110 lb/ft³g @NW 5 1/4“ – 63 lb/ft²LW 3 3/4“ – 34 lb/ft²
2010 Concrete Sustainability Conference 50 © National Ready Mixed Concrete Association
Embodied Energy of Floorgy• Total slab thickness (NW 6 ½”, LW 5 ¼”)• Embodied EnergyEmbodied Energy
– NW 1.3 Mbtu/cy; LW 1.8 Mbtu/cy– Energy about equal (less concrete & steel)
2010 Concrete Sustainability Conference 51 © National Ready Mixed Concrete Association
Floor Drying in Dalton, GA
2010 Concrete Sustainability Conference 52 © National Ready Mixed Concrete Association
2010 Concrete Sustainability Conference 53 © National Ready Mixed Concrete Association
2010 Concrete Sustainability Conference 54 © National Ready Mixed Concrete Association
Relative Humidity Probe Results
90.0%
95.0%
100.0%July
65.0%
70.0%
75.0%
80.0%
85.0%
July
40.0%
45.0%
50.0%
55.0%
60.0%July
20.0%
25.0%
30.0%
35.0% LW Burnished
NW Burnished
LW-S Burnished
AmbientJan-Feb
2010 Concrete Sustainability Conference 55 © National Ready Mixed Concrete Association
Relative Humidity Probe Results100.0%
LW Burnished
95.0%NW Burnished
LW-S Burnished
85.0%
90.0%
80.0%
2010 Concrete Sustainability Conference 56 © National Ready Mixed Concrete Association
NW Burnished NW Burnished vsvs NonNon--BurnishedBurnished
100.0%
NW Burnished
90.0%
95.0% NW Non-Burnished
85.0%
75.0%
80.0%
07/20/07 08/20/07 09/20/07 10/20/07 11/20/07 12/20/07 01/20/08 02/20/08 03/20/08 04/20/08 05/20/08 06/20/08
2010 Concrete Sustainability Conference 57 © National Ready Mixed Concrete Association
MVER Tests (moisture vapor emission rate)
July
10
12
14
r
LWLW-SNWLinear (3 lb)
4
6
8
lb/1
000
sq ft
/24
hr
Linear (3 lb)
July
0
2
/200
7
/200
7
/200
7
/200
7
/200
7
/200
7
/200
7
/200
7
/200
7
/200
7
/200
7
/200
7
/200
8
/200
8
/200
8
/200
8
/200
8
/200
8
/200
8
/200
8
/200
8
/200
8
/200
8
/200
8
/200
8
Jan-Feb
7/20
/
8/3/
8/17
/
8/31
/
9/14
/
9/28
/
10/1
2/
10/2
6/
11/9
/
11/2
3/
12/7
/
12/2
1/
1/4/
1/18
/
2/1/
2/15
/
2/29
/
3/14
/
3/28
/
4/11
/
4/25
/
5/9/
5/23
/
6/6/
6/20
/
2010 Concrete Sustainability Conference 58 © National Ready Mixed Concrete Association
Bottom Line… Floor Drying
• On suspended slabs there is no difference b t LW t d NW tbetween LW concrete and NW concrete performance, drying or adhesives
• The 3 pound MVER is questionable• The 3 pound MVER is questionable• The 75% relative humidity is questionable
2010 Concrete Sustainability Conference 59 © National Ready Mixed Concrete Association
Specified DensityDensity Concrete
Double tees: 128 ft. longg110 pcf, 6000 psi
2010 Concrete Sustainability Conference 60 © National Ready Mixed Concrete Association
2010 Concrete Sustainability Conference 61 © National Ready Mixed Concrete Association
Construction Efficiency Shipping Lightweight Precast ConcreteShipping Lightweight Precast Concrete
Project Example Number 1
Project Example Number 2
Shipping Cost Per Truck Load $ 1,100 $ 1,339pp g , ,
Number of Loads RequiredNormalweight Lightweight
431287
8766Lightweight
Reduction in Truck Loads287144
6621
Transportation SavingsShipping Cost Per Load $ 1,100 $ 1,339Reduction In Truck LoadsTransportation Savings
x144$158,400
x21$28,119
Profit ImpactT t ti S i $158 400 $28 119Transportation Savings(Less) Premium Cost of LWCIncreased Gross Margin
$158,400- 17,245
$141,155
$28,119- 3,799
$24,320
2010 Concrete Sustainability Conference 62 © National Ready Mixed Concrete Association
Lightweight concrete provides g g pBetter fire performance
2010 Concrete Sustainability Conference 63 © National Ready Mixed Concrete Association
Chesterfield Fire Training Housea g ouse6000 Fires, 6000 Hose streams25 Years5 ea s
It doesn’t get any better
2010 Concrete Sustainability Conference 64 © National Ready Mixed Concrete Association
Annual Energy Cost SavingsCalculated Using 1999 Energy Costs
City $/Block/Year
Boston $0.17
yyy
Omaha $0.13
Los Angeles $0 05
nerg
yne
rgy
nerg
y Los Angeles $0.05
Comparing 90 lb/ft3 SmartWall Systems to 135 lb/ft3 Heavy Weight Wall
EEE
2010 Concrete Sustainability Conference 65 © National Ready Mixed Concrete Association
Roof Top Garden, LDC Conference CenterLDC Conference Center
Salt Lake City
2010 Concrete Sustainability Conference 66 © National Ready Mixed Concrete Association
2010 Concrete Sustainability Conference 67 © National Ready Mixed Concrete Association
Are we part of the problem or p ppart of the solution ?
Sometimes a little energy must beSometimes a little energy must be consumed in the beginning
to save a lot of energy over a longto save a lot of energy over a long service Life
2010 Concrete Sustainability Conference 68 © National Ready Mixed Concrete Association
Making ESCS Lightweight AggregateMi i f t i l h l l l tMining of raw material shale, clay or slate
2010 Concrete Sustainability Conference 69 © National Ready Mixed Concrete Association
Fired in a Rotary KilnFired in a Rotary Kiln
2010 Concrete Sustainability Conference 70 © National Ready Mixed Concrete Association
FiredAt 2000°FAt 2000 F
plus
2010 Concrete Sustainability Conference 71 © National Ready Mixed Concrete Association
2010 Concrete Sustainability Conference 72 © National Ready Mixed Concrete Association
Expanded Shale, Clay and Slate UsesUses
StructuralLightweight
Lightweight Geotechnical Fill
Asphalt Chip Seal
g gConcrete
2010 Concrete Sustainability Conference 73 © National Ready Mixed Concrete Association
Sustainability is abouty
• Expanding on what works• Modifying what does not work• Transcending our current beliefs on how
d thiwe do things• It’s all about THE DESIGN PROCESS
taking a Holistic approach from thetaking a Holistic approach from the beginning
2010 Concrete Sustainability Conference 74 © National Ready Mixed Concrete Association
All great truth begin as blasphemyblasphemy.
2010 Concrete Sustainability Conference 75 © National Ready Mixed Concrete Association
And one great truth isAnd one great truth is
Everything Goes Better withEverything Goes Better with Lightweight Aggregate
2010 Concrete Sustainability Conference 76 © National Ready Mixed Concrete Association
Thank you
John Ries
www.escsi.org
2010 Concrete Sustainability Conference 77 © National Ready Mixed Concrete Association