TXDOT AND FLY ASH Andy Naranjo P E

TXDOT AND FLY ASH Andy Naranjo, P. E. Construction Division

Tx. DOT Concrete Stats Concrete Consumption Per Year Tx. DOT consumes approximately 150, 000 to 200, 000 tons of fly ash annually 2

CRCP Stats Lane Miles of Concrete Pavement Per Year 3

Class F Fly Ash Class C Fly Ash 4

Durability Requirements § Premature Deterioration: ASR, DEF, SRC – Tx. DOT 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 Dallam § Effective Freeze-Thaw Cycles Hansford Sherman Hartley Moore Oldham Potter Ochiltree Lipscomb o ins Roberts Hemphill Carson Gray Wheeler Donley Collingswoth n tch Hu 10 AMARILLO 5 Ha an Motley Co ch Lubbock Hockley Cottle Foard Wichita Clay WICHITA FALLS Dickens Crosby Wilbarger King Knox Archer Yoakum Terry Lynn Kent Garza Stonewall Throckmorton Haskell Denton Collin Hopkins Hunt Parker Tarrant FORT WORTH Martin Howard Mitchell Nolan Camp Callahan Taylor r me So ell -v Erath m uf Ellis Johnson Cass Marion Wood Upshur Van Zandt Smith Hood Eastland ATLANTA Titus an DALLAS Dallas Ka he St ep Jones Palo Pinto ns rd lfo ke Fisher ac Scurry Borden Rains ABILENE Andrews Harrison 0 TYLER Henderson Rusk Panola Navarro Glasscock Sterling Coke Runnels Reagan Irion Tom Green Hamilton BROWNWOOD Mills Concho Jeff. Davis Menard 0 Sutton oc he s LUFKIN Trinity Madison Polk Milam BRYAN Burleson Kimble Trayis Blanco San Jacinto Hardin Lee AUSTIN Terrell Tyler Walker Brazos Williamson Sabine Angelina Robertson Bell Burner Gillespie gd Houston Leon Llano Mason Crockett WACO Coryell Lampasas San Saba Schleicher Pecos co Falls Mc Culloch Shelby Na Freestone e Upton Mc Lennan ton Crane Cherokee Anderson Bosque es Ward Reeves Comanche Lim SAN ANGELO ODESSA Culberson Brown Coleman Newton Midland San Augustine Hill Ector Winkler Jasper Loving Hudspeth Grimes EL PASO – Fly Ash or Air? Wise Jack Young Sh Dawson Bowie Delta Rockwall Gaines Red River PARIS Fannin Grayson Cooke LUBBOCK El Pasd – Primarily an issue for North Texas 1 Lamar Baylor Morris Floyd g ra n Hale eg Lamb Bailey 5 § Unburnt/Activated Carbon em Franklin C – Below 17°F for more then 10 5 hours with moisture present 1 rd CHILDRESS Gr Hall gu e Briscoe nta Swisher Mo Castro hil Parmer Armstrong es s Randall dr Deaf Smith Montgomery Washington Liberty Orange BEAUMONT Uvalde Chambers Gonzales Wharton YOAKUM Wilson n Fort Bend Lavaca to Guadalupe Medina SAN ANTONIO HOUSTON Colorado es Bexar Kinney Harris Fayette Caldwell Comal Bandera alv Kendall Real Jefferson G Val. Varde Austin Hays r Brewster Bastrop Kerr Edwards Walle Presidio Brazoria Dewitt Jackson Zavala Frio Matagorda Karnes Atascosa Ma Victoria ck veri Calhoun La Salle Mc Mullen Jim Wells Webb – Only air entrain when shown on the plans – No specified air content listed – Must use an air entraining agent Bee Refugio Live Oak s Dimmit Nuceces Duval CORPUS CHRISTI LAREDO Zapata San Patricio Ar an sa § 2014 Spec changed the default for air entrainment. Goliad Kleberg Jim Hogg Starr Brooks Kenedy Hidalgo Willacy PHARR 6

Plant/Seasonal Outages § Unusually long outages can delay project schedules § Tx. DOT 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

Tx. DOT Concrete Sustainability Potential CO 2 Reduction Mix Design CO 2 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 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 Potential of CO 2 30% Reduction 51, 000 Type IL w/35% SCM 8

QUESTIONS?