ASPHALT BINDERSPast, Present, and Future

90th Annual Transportation Short Course

Texas A&M University

October 11, 2016

Robert B. McGennis, P.E.

The HollyFrontier Companies

Phoenix, AZ

The HollyFrontierCompanies

Headquartered in Dallas, TX NYSE: HFC

5 complex/integrated refineries OK, NM, KS, WY, UT

457,000 bpd capacity

6 Asphalt Terminals Artesia, Albuquerque,

Rosario, NM

Glendale, AZ

Catoosa, OK

Cheyenne, WYWho are those guys?

What Dr. Newcomb* asked me to cover:

How asphalt binders have changed over the years

Refinery changes

Polymers

Superpave

Where we need to go…

*Said I got a visa to Aggieland and safe passage…

Once upon a time in Trinidad…

Earliest Asphalt Binder Specs Addressed TLA (and similar)

Color

Solubility in carbon disulfide

Asphalt Manufacture

Standard OilRichmond, CA1914

8

Fractional Distillation

Crude

Oil

Crude

Furnace

Distillation Column

Gas

Naphtha

Gasoline

Kerosene

Diesel

Lubricating Oil

Heavy Gas Oil

Residue

4

6

8

12

16

36

44

70+

Carbons

700 F

100 F

600 F

200 F

300 F

400 F

500 F

Vapor

Cooled Reflux

Cooled Reflux

Cooled Reflux

Cooled Reflux

Liq

uid

Penetration Test and Spec(1920s – 1970s)

PenetrationGrades: AASHO M20

40 - 50

60 - 70

85 - 100

120 - 150

200 - 300

hard

er

100 g100 g

Penetration

0.1 mm

0 sec 5 sec

run test at 25 C (77 F)

The Problem with Pen Spec

25 60 135-15

Consistency

(pen)

hard

soft

pen

AB

C

Temperature, C

This is all

we see in

this system…

they all look

the same!

The Problem with Pen Spec

25 60 135-15

Consistency

(pen)

hard

soft

pen

AB

C

Temperature, C

Asphalt Manufacture

HollyFrontierEl Dorado, KS2015

What a Modern Refinery Does

A refinery maximizes the conversion of crude oil into desirable products (transportation fuels)

Residue ~ 37%

Lube Oil ~ 15%

Jet & Diesel ~ 21%

Gasoline ~ 25%

LPG ~ 2%

Residue ~ 8%

Jet & Diesel ~ 37%

Gasoline ~ 49%

LPG ~ 3%

Refined WTI CrudeDistilled WTI Crude

Volume Gain ~ 6%

The Refining Barrel

42 Gallons

~50%

~50%~90%

Not all crude oils are created equal…

Lots of asphalt! No asphalt!

Source: US Energy Information Administration

More Asphalt

Source: Tom Shetina, HFC

FCC

Unit

Diesel

Hydrotreater

Alkylation

Unit

Hydrotreater Isomerization

Unit

FCC Gasoline

Hydrotreater

Atm

os

ph

eri

c D

isti

lla

tio

n

Vaccu

mD

isti

llati

on

CokerPDAPitch

Gas Oil

Diesel

Jet Fuel

Kerosene

HydrotreaterHeavy

Naphtha

Catalytic

ReformerSweet

Naphtha

Reformate

Light

Naphtha

Merox

Treater

Isomerate

Vacuum

Resid

Atm

osp

he

ric

Bo

tto

ms

Asphalt or Fuel Oil

FCC

Hydrotreater

Gas Oil

Hydrocracker

Heavy

Gas Oil

Light

Gas Oil

Gasoline

Jet Fuel

FCC Gas Oil

Petroleum Coke

Gas

Processing

Merox

TreaterPropane

Butane

Amine

Treater

Refinery Fuel Gas

Claus Sulfur

PlantSulfur

Diesel

Hydrocracked Gasoline

Distillate

Isobutane

Olefins

Fuel Oil

Other Gasses

Gas Oil

Naphtha (after hydrotreating)

Gas H2 Gas H2

Gas H2

Gas H2

Gas H2

(or NHT then Cat Reformer)

Light Cycle Oil

Ga

so

lin

e B

len

din

g

High RVP Season

Alkylate

Treated Gasoline

Gas H2

Gas H2

Gas

Gas

Gas H2

So

ur

H2O

Str

ipp

er

Steam

Sour

Waters

Stripped

Water

H2S and NH#

to Sulfur Plant

Crude

Oil

Complex/Integrated Refinery

Refinery Processes That Make Asphalt

Separation

Atmospheric distillation

Vacuum distillation

Solvent Deasphalting Unit (SDA, PDA)

ROSE and other HCC Units

Conversion

Oxidizer

Coker, FCC, etc. – NOT!!

Feed Pitch

Viscosity Test and Spec(1970s – 1990s)

Grades: AASHTO M226

AC 2.5, AC 5, AC 10,

AC 20, AC 30, AC 40

Do this at 140 F

plus some other

tests.

Kinematic (275 F) Absolute (140 F)

Texas Hwy Dept Item 300

Viscosity Specifications

Advantages

viscosity is a more fundamental test

characterizing asphalt over wider range of temperatures

control of temperature susceptibility

Disadvantages

did not work well with modified asphalts (fact vs perception?)

bad timing?

something missing?

Bad Timing???

Winnie, Texas, 1981

TRB Special Report 202 – America’s Highways: Accelerating the Search For Innovation (1984)

“… the procurement process for asphaltbegan more than 70 years ago…thisprocess does not accommodate improved adhesion, wetting, andoxidation characteristics…the current knowledge of such desireable properties…is not sufficient to be able to incorporate them in a procurement specification.”

Something missing???

NCHRP Report 269, Paving with Asphalt Cements Produced in the 1980s, Epps, Button, and Gallaway, 1984

“The physical properties of asphalt cementsare…more variable…than 20 years ago, even though they remain within specificationvalues; but variations in other factors maymask the influence of this variation on pavement performance.”

Where Did PG Come From?(It’s a relatively new thing! 1993 to present)

Strategic Highway Research Program

1987-1993

$50 million research project by state DOTs

primarily at universities

Product was called Superpave

Superior Performing Asphalt Pavements

PG binder spec with new tests

mix design system

Adopted throughout (almost) all of US by now

binder spec - AASHTO M320, TxDOT Item 300

mix design and analysis (no)

What’s this “PG” All About?

PG 64-22High pavement temp (C)

to protect against rutting

Low pavement temp (C)

to protect against

thermal cracking

Another Way to Look at It

Testing binder to get

good performance for

this layer at expected

pavement temps.

Test asphalt binder at temps

this layer feels

(high, intermediate, low)

PG Physical Property Tests

Dynamic Shear Rheometer (high temp grade)

Bending Beam Rheometer(low temp grade)

PG Plus

Tests added to AASHTO M320 to ensure binder is polymer modified

elastic recovery (TxDOT)

cold ductility

toughness and tenacity

force ductility

others…

Types of Modifiers

• Inorganic acids (e.g., PPA)

• Polymers and attendant stuff

• Construction Enhancers (e.g., WMA additives)

• Waste Post Consumer Products (e.g., scrap tires, shingles)

• Fillers and Fibers

• Antistripping agents

• Hydrocarbons

• Antioxidants

• Extenders (e.g., REOB)

• Rejuvenators

Log Temperature

Log Log Stiffness, Viscosity, etc.

Unmodified

polymer modified

Modification via polymer

Types of Polymers

• Elastic Type

- SB diblock (Dynasol 1205)

- SBS (LCY 3501, Kraton D1118)

- SBR latex (Ultrapave 1156)

- Waste rubber (CRM WRF-14)

• Plastic Type

- EVA (Exxon Polybilt 103)

- polyethylene (Novaphalt)

Polymer Modified Asphalt (Elastic)

Advantages

Significant performance history

Elastic effect

Improved cohesion t = s tan (f) + c

Many specs designed around stretchy polymers (no mysteries)

Favorable co-modifier with others (e.g., PPA)

Disadvangates Can be challenging to

manufacture Compatibility can be a

problem Tougher to handle Sometimes not heat stable Challenge to emulsify Sometimes supply/price

not stable Relatively expensive

0

5

10

15

20

25

30

35

40

1960 1970 1980 1990 2000 2010 2020

Mil

lio

ns o

f T

on

s S

old

Source: Asphalt Institute

Asphalt Usage in U.S.(1963-2015)

The Future?

• Asphalt Manufacture

• heavier, sour crude

• more blending to grade

• AASHTO M332 (new PG)

• Compliance vs stiffness of binder

• no more “bumping” of grades

• More PG+

DTc

• better lab aging (hopefully)

• compatibility tests

The Future?

• Modified Binders

• ability to quantify effect on mix

• “HIMA”

• boutique polymers for better compatibility

• Asphalt Usage

• National - ????

• Texas UTP + ???

Thank you…come see me in Arizona some time!