Update on ACPA/IGGA Surface Characteristics Research

Presented toRPUG Meeting

Atlanta, GADec 9, 2009

Larry Scofield, P.E.

Lets Look Back In Time…..

Noise … a Quality of Life Issue?

Consumer Perception: Concrete is Noisier than Asphalt

Concrete Industry Off to Slow Start!!---The 3 dBA Rule---

No Standardized Test Method For Measuring Tire/Pavement Noise

Transverse Tining Most Widely Used Texture– FHWA Tech Advisory

Volume(Too Loud)

Frequency(Off Station)

Noise Issues

Quality of LifeInvestment DecisionsThe Future is Different

AASHTO TP-76

Two Types of Annoyance

Volume (Too Loud) Frequency (Off Station)

100

104

Frequency

dBA

110Phx

dBA

Tonal Spike

2005 Concrete Industry Mobilizes

PCA Provided Funding to ACPA to Conduct a Three Year Research Project on NoiseACPA Contracted with Purdue University to Conduct Noise Research on:IGGA Developed Grinding Head and Provided Technical Expertise to Purdue

Purdue Noise Research

Evaluate Existing Texture ModificationEvaluate New Innovative Textures ConstructionRolling Resistance,Texture, and Friction of Tested Surfaces

Purdue Research-- Tire Pavement Test Apparatus (TPTA)

Purdue Existing Texture Research (Diamond Grinding)

Blade WidthBlade SpacingJoint Slap

Spacer Blade

Purdue Existing Texture Research Results: Fin Profile, Not Blade Width and Spacing, Was What Was Important

Final NGCS Research at Purdue

Effect of Groove Spacing, Width, Depth, Insert

1/8”-1/4”

Groove Width

Groove SpacingInsert

3/8”-3/4”Micro Texture

NGCS LITE---Renewable Surface Texture

MicroTexture

Grooves for Macro Texture

NGCS Construction

Flush Grind

Grooved

Changes in Kansas I-70 OBSI Overall Level Over Time (ISU Data)

NGCS Update at MnROADs

101.0 100.7

101.8

105.0

102.8

94

96

98

100

102

104

106

108

110

Soun

d In

tens

ity L

evel

, dB

A

Pavement Section

Montecello NGCS

Cell 7 NGCC

Cell 9NGCS LITE

MontecelloCDG

Cell 8 CDG

30 30 50

Current and Future NGCS Sites10% of the States Now Have NGCS to Evaluate—In 2010 20%

3

How Does Grinding Stack Up

Transverse TineConventional

Diamond Grinding

Longitudinal Tine Next Generation Concrete Surface

103-110dBA

101-106 dBA

100-104dBA

99-101dBA

Traffic

Twice as

Loud

Purdue New Surface Textures Results

Establish the Lower Limit Possible with ConcreteEvaluate Unique Geometric Patterns

CirclesDiamondARFC TextureWaffle PatternRandom Waffle Spherical

Imprinting Roller for Diamond Pattern Texture

Cast Diamond Pattern

Circle

Circles 8 mm in diameter

Spheres

Spheres 8 mm in diameterOverlap so only about 6 mm between peaks of adjacent spheres

Results of Geometric Patterns

84

86

88

90

92

94

96

98

100

102

Tined Uniform Waffle

Tined w/Burlap

Exposed Aggregate

Random Waffle

Sphere Diamond Circle Blank

Ove

rall

A-w

eigh

ted

inte

nsit

y le

vel

(dB(

A)

re: 1

pW

/m2 )

Goodyear Aquatred

Uniroyal Tiger Paw

Uniroyal SRTT

Average of Three Tires

Comparison of Different Textures

84

86

88

90

92

94

96

98

100

102

Tined Sphere Phase 2 blank Circle IT Blank Full grind

Ove

rall

A-w

eigh

ted

inte

nsit

y le

vel (

dB(A

) re

: 1 p

W/m

2 )

Goodyear Aquatred

Uniroyal Tiger Paw

Uniroyal SRTT

Average of Three Tires

Growing Old Or “Acoustic Longevity”

Changing Performance Over

Time

Pavement Age (Yrs)

Noise Level (dBA)

Asphalt

Concrete

Why Is Acoustic Longevity Important?

92

94

96

98

100

102

104

106

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

OB

SI L

evel

(dB

A)

Years Since Constructed

Kansas Conventional Diamond Grinding

FHWA Barely Perceptible

Zone

Arizona Asphalt Rubber Friction Course

Joint Slap Spreadsheet

Joint Calculation• Distance between joints• Vehicle speed • Groove width and depth

Pavement Noise Calculation• Overall level – input texture generated noise level• Texture noise level – input measured overall level

Hydroplaning

(Hydroplaning)

Mean Texture Depth (Kansas I-70)

1.9

1.5

1.2

1.0

0.9

0.7

0.3

0

1

2

Mea

n Te

xtur

e D

epth

(mm

)

Pavement Section

NGCS

GroovedAstroTurf

ExposedAggregate

CDG

AstroTurfDrag Long

Tined

BurlapDrag

Water Depth For Hydroplaning (I-70 Data) (Utah Requirements)

1.81.9 2.0 2.0 2.1 2.1

2.2

0

1

2

3

Max

imum

Wat

er D

epth

(mm

)

Pavement Section

NGCS

GroovedAstroTurf

ExposedAggregate

CDGAstroTurfDrag

LongTined

BurlapDrag

Maximum Allowable Water Depth

Friction Results!!!

Copyright © 2008 Ron Kurtus, and School for Champions LLC @http://www.school-for-champions.com

ASTM Locked Wheel Skid Testing of NGCS

New Construction SurfaceEstablish Acoustic Lower Limit for Non-porous SurfacesIdentify Efficient Geometric Patterns, if anyEvaluate Toppings

51

36

5148

44

4945

49

74

66

57 58

54 55

48

56

0

10

20

30

40

50

60

70

80

Fric

tion

(SN

40)

Texture Type

Ribbed Tire (SN40R)

Smooth Tire (SN40S)

Random Transverse

Tined

Next Generation Concrete Surface

NGCSLITE

Conventional Diamond Grinding

Shadow effect indicates testing at construction

10/31/08

10/23/07

5/28/08

10/31/08

10/23/07

5/28/08

10/31/08 10/31/08

CT-342 Friction Testing at Angles

Increasing

Grooved Vs Non-Grooved Astro Turf Friction Results

0.0

10.0

20.0

30.0

40.0

50.0

60.0

40 50 70

Fric

tion

Val

ue (S

N)

Speed (mph)

Astro Turf

Grooved Astro Turf

Note: (1) Ribbed Tire is Dashed Line(2) Smooth Tire is Solid Line

In Summary

The NGCS provides a quiet surfaceJoint Slap Model Can be Used to Evaluate Transverse Joint Designs for Impact on Overall Pavement NoiseSeveral Geometric Patterns Developed Low Noise SurfacesAcoustic and Friction Longevity is Still Under Evaluation- The Journey is Underway

Questions?