CE 3700 Final Exam

Densification property

%Gmm

Cutbacks: -Rapid cure (ex. ______) is a ____ volatility of solvent -Medium cure (ex. ____) is a ____ volatility of solvent -Slow cure (ex. ______) is a ___ volatility of solvent

-RC: gasoline; high -MC: kerosene; moderate -SC: low viscosity oil; low volatility

Dynamic Shear Rheometer -Test is done at several temperatures until it surpasses the minimum of _____ -Identifies _____ and _____ properties and behaviors -Finds binder's _____ ____ modulus and ____ ____ -What results in a stiff binder -When emphasizing rutting resistance, a minimum value is placed on the ____ component of the _____ ____ modulus -When emphasizing fatigue cracking resistance- _____ is desired and _____ has to be limited -Modulus varies between ____ and ____. -Angle varies between _____ and ____ degrees with ____ degrees being complete viscous behavior

1 kPa viscous and elastic complex shear; phase angle high modulus and low angle elastic; complex shear elasticity; stiffness 0.07-0.87 psi 50-90

4 Steps in Mixture Design

1. Materials selection 2. Design agg. structure 3. Design asphalt content 4. Evaluate mixture

Two conditions that low temperature cracking can occur under

1. temperature drops dramatically 2. repeated expansion and contraction due to temp fluctuation

Properties considered in evaluation of aggregates for HMA (6)

1.Internal Angle of Friction 2. Particle Shape 3. Cleanliness 4. Toughness 5. Durability 6. Absorption

Maximum value of flat and elongated particles

10%

For FAA, aggregate is allowed to flow freely into a ____ cm^3 cylinder

100

VMA criteria: minimum value is ___%

13%

Penetration Grading -developed in ____ - 1 penetration=___ mm -Done at room temperature -In LA, regulation penetration # is -Colder climates can use binder with ____ penetration # -3 drawbacks

1918 0.1 mm empirical 40 higher Results strictly empirical; only at one temp; rate of loading depends on tested material

An aggregate is considered 100% crushed if ____ or more faces are crushed

2

Mineral filler passes the No. ____ sieve

200

0 crushed faces (<_%) 1 crushed face (>__%) 2 crushed faces (>_%)

25 25 50

VTM: Air voids tend to be in the range of __-__% in a dense graded mixture

3-5

Determine optimum asphalt binder content that corresponds with a VTM of __%

4

Minimum sand equivalent value is __%

45

Natural sands typically <__ FAA Manufacture sands typically <___ FAA

45 42

Minimum % of FAA to prevent _____

45; rutting

IN the U.S. there are __ million miles of road. ___ million are asphalt/concrete, ___ million are gravel, ___ million are un-surfaced

4; 2.3, 1.3, 0.4

__-__% of HMA weight is due to asphalt. __-__% of HMA volume is due to asphalt

5-8; 15-25

Capillary Viscosity Test: -Absolute viscosity can be found at temp of ____ degrees C -Kinematic viscosity can be found at a temp of _____ degrees C -Units? -1 Drawback -Shows relationship between ___ ____ and ____ ____ -More viscous the asphalt, less _____ will occur -Hotter climates want ____ viscous binder -AC 10 has a viscosity of ____ poises

60 135 poises Only tests at a specific temp shear stress to shear rate rutting high 1000

VFA's range is specified between ____-____%. Minimum value is specified to ensure sufficient amt of asphalt for ______. Maximum value is specified to prevent excessive amt of asphalt cement for mixture ______

65-75% durability stability

Range % of VFA

65-80%

%Gmm(Ninitial) maximum

89%

FAA is based on a No. ___ material and on ____ _____ in loose sample

8; air voids

____ percent of vehicle travel occurs on hard surfaces

95

Minimum percent for 1 fractured face is ____. Minimum percent for 2+ fracture faces is ____.

95%;90%

___ percent of hard surfaced roads are asphalt

96

%Gmm(Nfinal) maximum

98%

AASHTO

American Association of State Highway Transportation Officials

ASTM

American Society of Testing Materials

3 Types of Asphalt

Asphalt cements, cutbacks, and emulsions

Materials Selected are

CA, FA, asphalt cement

Concensus properties of aggregate (4)

CAA FAA Flat, elongated particles Clay content

_______ regulations are increasingly limiting the use of cutback asphalt (fumes)

Environmental

2 types of mixture specific gravity

Gmm and Gmb

Relationship of Gsb to Gse and Gsa

Gsa>Gse>Gsb because volume of water is least in Gsa and most in Gsb

3 types of aggregate specific gravity

Gsb, Gse, Gsa

CAA: Elongated is the ratio of ____ to _____ Flat is the ratio of _____ to ______

Length to width Width to thickness

3 Types of Concrete Mix Design Methods

Marshall (TN), Hveem, Superpave

2 Types of Commercial Asphalt Cement

Natural; petroleum-based

Amount of compaction energy is defined by

Ninitial, Ndesign, Nmaximum

What does each set of letters and numbers mean? PG 64-22

PG-performance grade 64-average 7 day high pavement temperature 22- minimum pavement temperature

Another way to put total asphalt content besides %AC is

Pb

Objectives of mix design is to

Resist permanent deformation, fatigue cracking, low temperature cracking, moisture induced damage, and skid. Consider workability

Purpose of Mixture Design

Selection of an optimum amt of asphalt cement content to satisfy a prescribed volumetric and densification

Superpave stands for

Superior Performing Asphalt Pavement

Source properties of aggregate (3)

Toughness Soundness (durability) Deleterious materials (cleanliness)

Natural commercial asphalt cement can be found in _____ and _____

Trinidad and Venezuela

Volume of fine aggregate formula in terms of M (mass) and G (specific gravity)

V=M/G

VFA is the percentage of ____ filled with asphalt

VMA

Volumetrics Criteria (3)

VTM VMA VFA

VFA

Voids Filled with Asphalt

VMA stands for

Voids in Mineral Aggregate

VTM stands for

Voids in Total Mix

Toughness pertains to an aggregates resistance to ______

abrasion

Pavement performance is influenced by ______

aggregate

Mineral Aggregate for HMA Definition

any hard, inert mineral materials used for mixing in graduated particles or fragments. It includes sand, gravel crushed stone, slag, and rock dust or powder

Gsa

apparent specific gravity when no pores are filled

VMA is the volume available for _____ and _____

asphalt and air

2 bituminous materials

asphalt and tar

Clay on aggregate particles reduces ______ ______

binder adhesion

Synonym for HMA: _____ paving mixtures

bituminous

Gsb is

bulk specific gravity when all aggregates pores are filled

Tar -Produced from ____ of ____ -Hazardous to health -____ resistance

burning of coal fuel

Asphalt Cement: -______ material -Naturally occurring -Produced by ______ _____ -Excellent adhesive -Waterproof? yes? no? -Mainly used in ____ applications

cementitious petroleum distillation yes paving

Superpave performance grading system is based on ____

climate

Suitability of Aggregates for Use in HMA Toughness: Conducted on _____ aggregate Initial weight obtained is on Sieve No. __ Final weight obtained on Sieve No. ___ % Loss equation

coarse 4 16 [(initial wt-final wt)/initial wt]*100

Primary consolidation is under ______ conditions

construction

VTM (Va) _____ when %AC increases because

decreases; because asphalt fills the voids

All volumetrics are to use N_____

design

When collecting Gmb, laboratory samples are typically _____ and field samples are typically _____

dry; wet

Gse

effective specific gravity is of the solid volume and volume of permeable pores not filled with asphalt

Emulsion Asphalt: classified based off of _____ -Anionic -____ charge -Aggregate with + charge (ex. ____) -Cationic - _____ charge - Aggregate with - charge (ex. ______)

emulsifier negative; limestones positive; silica gravel

Secondary consolidation is at _____ __ ______ performance

end of life

ESAL stands for

equivalent single axle load, 18000 lb

Used to estimate the relative proportions of _____ and _____

fine agg. and dust

Particle shape pertains to whether the aggregate is _______ and/or ______

flat &/or elongated

CAA is based on _____ _____

fractured faces

Design agg. structure by selecting an agg. _____

gradation

The more angular the aggregate, the _____ the void content

higher

%VFA _____ when %AC increases because

increases because more asphalt means more voids are going to be filled with asphalt

%Gmm _____ when %AC increases because

increases; because more asphalt allows for mixture to become more dense

Cutback asphalt is ____ at room temperature

liquid

Mineral aggregate for HMA is responsible for ______ _______ capacity of pavements

load supporting

Evaluate mixture by figuring out _____ ______

moisture susceptibility

VMA's minimum value is specified based on the _____ ______ ______ ______ in the mixture to ensure its ______

nominal maximum aggregate size; durability

Design asphalt content by finding the _____ ______ _____ Content

optimum asphalt cement

Gmm eliminates the volume of ______ _____. It considers volumes of _____ and _____ _____. Calculations done with values collected with ____ _____

permeable voids; aggregate and asphalt binder; loose aggregate

Cutbacks: Asphalt cements "cut" with _____ _____

petroleum agents

Bending Beam Rheometer -Sample has to have undergone _____ ____ testing and has been placed in a ____ ____ ___ -Determines ____ and ____ state properties -Measures sample's ability not to succumb to _____ -Useful in finding binder's ____ stiffness due to time -Can find _____ ______ modulus -m-value is the _____ of a master stiffness curve; the _____ the slope, the higher the relaxation property -Minimum value is

pressure aging; cold liquid bath stiffness and relaxed low temp cracking creep stress relaxation slope 0.3; higher

Asphalt cements are generally ____ produced material

refinery

Pressure Aging Vessel -Sample must undergo ____ ____ ____ ____ test -Simulates ____ term aging -tests how much the sample ____ -More ______ then more _____ asphalt gets -to prevent cracking, minimum amount of _____ needs to occur

rolling thin film oven long (8-10 years) oxidizes oxidation; viscous oxidation

Internal angle of friction pertains to whether or not the aggregate is _____ or ______

round or cubical

Clay content is based on _____ ______ value

sand equivalent

At room temperature, asphalt cement is _____ and _____ at high temperatures

semi-solid; liquid

Rolling Thin Film Test -Simulates ____ term aging -At a temp of ____ degrees -Due to ______ to _____ and ____ of ____, volatile components of the asphalt cement are lost -Typically mass loss is between ___-____% -If mass lass is greater than ___% then particular asphalt fails -Higher the mass loss, the more ____ the binder becomes

short 163 exposure to heat and jets of air 0.05-0.5% 1% viscous

Rotational Viscometer -Measures the ______ needed to keep spindle rotating at ____ rpm -Conducted at ____ degrees C -Tests whether or not asphalt can be ____ _____ _____ -Maximum value of ___ -Measures _____ of cement, which directly corresponds to the dynamic viscosity

torque; 20 130 ran through pipes 3 Pa*s stiffness

Emulsions: Mixture of asphalt cement, ______, and _____ ______

water and emulsifying agents