TXDOT AND FLY ASHAndy Naranjo, P.E.Construction Division

TxDOT Concrete Stats

Concrete Consumption Per Year

-

500,000

1,000,000

1,500,000

2,000,000

2,500,000

3,000,000

3,500,000

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014

Conc

rete

Con

sum

ption

, CY

Retaining Walls

Bridge Decks

PS Beams

Substructure

Drilled Shafts

Pavement

2

TxDOT consumes approximately 150,000 to 200,000 tons of fly ash

annually

CRCP Stats

3

0

3000

6000

9000

12000

15000La

ne M

iles

of C

oncr

ete

Pave

men

t

CRCPJCP

Lane Miles of Concrete Pavement Per Year

E l P a s oE l P a s o

O d e s s aO d e s s a

A m a r i l l oA m a r i l l o

L a r e d oL a r e d o

L u b b o c kL u b b o c k

S a n A n g e l oS a n A n g e l o

P h a r rP h a r r

A b i l e n eA b i l e n e

W a c oW a c o

A u s t i nA u s t i n

T y l e rT y l e r

B r y a nB r y a n

Y o a k u mY o a k u m

P a r i sP a r i s

C h i l d r e s sC h i l d r e s s

L u f k i nL u f k i n

S a n A n t o n i oS a n A n t o n i o

D a l l a sD a l l a s

W i c h i t a F a l l sW i c h i t a F a l l s

A t l a n t aA t l a n t a

B r o w n w o o dB r o w n w o o d

H o u s t o nH o u s t o n

B e a u m o n tB e a u m o n t

F o r t W o r t hF o r t W o r t h

C o r p u s C h r i s t iC o r p u s C h r i s t i

§̈¦20

§̈¦10

§̈¦35

§̈¦40

§̈¦27

§̈¦69

§̈¦44

§̈¦110

¢67

¢90

¢87

¢82

¢62

¢59

¢79

¢180

¢84

¢69

¢83

¢77

¢80

¢281

¢385

¢60

¢287

¢285

¢96

¢290

¢190

¢70

¢183

¢380

¢57

¢54

¢271

¢175

¢181

¢81

¢277

¢377

¢75

¢259

¢283

¢71

Class C Fly Ash

Class F Fly Ash

4

Durability Requirements

Premature Deterioration: ASR, DEF, SRC

– TxDOT relies heavily on fly ash for mitigation these type of distresses

High Performance Concrete: Typically required in coastal and North Texas

– Concrete Mix Options 1-4: All rely on SCM to meet requirements

• Fly ash only locally available option

• Small amount of Silica Fume used in Panhandle

– Permeability: State mandate to use brine solution as deicing material

Mass Concrete Placements

– High volume fly ash mixes needed to reduce peak temperatures during curing large concrete elements

5

Air Entrainment

6

Dallam Sherman Hansford Ochiltree Lipscomb

Hartley Moore

Hutchinso

nRoberts Hemphill

Oldham Potter Carson Gray Wheeler

Deaf Smith Randall Armstrong DonleyCollings-woth

Parmer Castro Swisher Briscoe Hall

Child

ress

Bailey Lamb Hale Floyd Motley

Dickens King KnoxCoch

ran

HockleyLubbock

Crosby

GarzaLynnTerryYoakum

Gaines Dawson Borden Scurry Fisher Jones

Kent Stonewall HaskellThrock-morton

Baylor

WilbargerWichita

WICHITAFALLS

Clay

Archer

YoungJack

Howard Mitchell NolanTaylor

CallahanEastland

Glasscock Sterling Coke Runnels

Shac

kelfo

rd

ReaganIrion

Mon

tagu

e

Cooke Grayson Fannin

Lamar

Delta

Red River

PARIS

Bowie

Wise Denton CollinHunt Hopkins

RainsWood

Upshur

Marion

Cass

Titus

Morr

is

Camp

ATLANTA

Harrison

Smith Gre

ggVanZandt

Henderson TYLER

Rusk Panola

AndersonCherokee

NacogdochesFreestone

DallasDALLAS

Rockwall

Step

hens Palo

Pinto

Parker Tarrant

Kauf

man

Shelby

San

A

ugu

stin

e

SabineHoustonLUFKIN

Angelina

TylerPolk

Trinity

Jasp

er

New

ton

SanJacinto

Walker

Leon

Navarro

Ellis

Hardin

FORTWORTH

Erath

HoodJohnson

Somer

-vell

Hill

BosqueMc

LennanHamilton

Coryell

Bell

Falls

WACO

Limestone

Robertson

Madison

Milam

Brazos

Gri

mes

Burleson

BRYAN

Washington

Lee

Austin

Fayette

Harris

Montgomery Liberty

BEAUMONT

Orange

Jefferson

Chambers

Galve

ston

HOUSTON

FortBend

Brazoria

Matagorda

Wharton

Colorado

LavacaGonzales

Dewitt

YOAKUM

Jackson

Victoria

Calhoun

Walle

r

Goliad

Bee Refugio

Aran

sas

Karnes

LiveOak

JimWells

SanPatricio

Nuceces

CORPUSCHRISTI

Kleberg

Kenedy

Willacy

Hidalgo

BrooksJim

HoggZapata

Starr

PHARR

Duval

Webb

LAREDO

La SalleDimmit

Zavala Frio Atascosa

McMullen

Guadalupe

Wilson

Bexar

MedinaUvalde

Real Bandera

Kerr

Kendall

GillespieBlanco

Kinney

Maverick

SANANTONIO

Edwards

Sutton Kimble

Mason LlanoBurner

Williamson

Trayis

AUSTIN

BastropHays

CaldwellComal

Brown Comanche

BROWNWOOD

Coleman

Mills

McCulloch

San Saba Lampasas

Concho

Menard

SANANGELO

Schleicher

TomGreen

Andrews Martin

Midland

Pecos

Ector

Crane

Ward

WinklerLoving

Crockett

ValVarde

Upton

Terrell

Reeves

Culberson

JeffDavis

Brewster

Presidio

Hudspeth

El Pasd

EL PASO

ODESSA

LUBBOCK

AMARILLO

ABILENE

Cottle Foard

HardemanCHILDRESS

Fran

klin

10

10

5

5

1

1

0

0

Effective Freeze-Thaw Cycles

– Below 17°F for more then 5 hours with moisture present

Unburnt/Activated Carbon

– Primarily an issue for North Texas

– Fly Ash or Air?

2014 Spec changed the default for air entrainment.

– Only air entrain when shown on the plans

– No specified air content listed

– Must use an air entraining agent

Plant/Seasonal Outages

Unusually long outages can delay project schedules

TxDOT has made some mix design allowances for periods of fly ash shortages

– Trial batches waived

– Straight cement mixes

High Performance Concrete

– Sticking to our guns on this in most regions (North Texas and Costal)

– Will consider non-HPC mixes in substructure not over bridge joint on case by case basis

7

TxDOT Concrete Sustainability

8

Mix DesignPotential

CO2 Reduction

CO2 Equvialent (Passenger Vehichels)

520 lb/cy --

20% SCM 15% 26,500

35% SCM 27% 47,500

OAG Mix 13% 23,000

OAG Mix w/20%SCM

22% 22,000

Type IL w/20% SCM

20% 35,300

Type IL w/35% SCM

30% 51,000Potential Reduction of CO2

Project 0-6858, “Evaluating Limestone Cements with >15% Limestone• 20% and 30% limestone contents• Previous research has shown synergy

with Class C fly ashes.• Primary use in paving concrete

600,000

650,000

700,000

750,000

800,000

850,000

900,000

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020

Tons

of C

O2

Prod

uced

Year

Best Case: 100% Contains Type IL Cement and 35% SCM

15% Reduction from 2009 Level

QUESTIONS?

9