CORRELATION BETWEEN LABORATORY AND FIELD PERFORMANCE OF GREYWACKE AGGREGATES

Qinxin Cao, Adelia Nataadmadja, and Dr. Douglas Wilson

Overview

Background Project Objectives Methodology Results Conclusions Further Research Direction

Why is the research important?

ROAD SAFETY

Greywacke

Skid Resistance (μ) Performance of Greywacke Sandstone Rock Aggregates cf Melter Slag Aggregate Under Accelerated Polishing

y = 0.007x2 - 0.060x + 0.548

R2 = 0.823

y = 0.049x2 - 0.213x + 0.614

R2 = 0.835

y = 0.010x2 - 0.118x + 0.875

R2 = 0.995

y = 0.006x2 - 0.065x + 0.887

R2 = 0.982

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0

Accelerated Polishing Duration - Time (hours)

DF

T T

este

r C

oF

(μ

)

G1 Pol G2 Pol G3 Pol MS1 Pol

Poly. (G1 Pol) Poly. (G2 Pol) Poly. (G3 Pol) Poly. (MS1 Pol)

MS1 PSV = 55

G3 PSV = 63

G1 PSV = 51

G2 PSV = 55*

Greywacke

0 1 2 3 4 50.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

Time in Polishing (hours)

Dyn

am

ic F

rict

ion

Test

er

(μ)

G4 PSV=53

6

Project Objectives

Correlating the laboratory and measured field skid resistance performance of the G4 Auckland greywacke aggregate

Comparing the field performance between the G4 Auckland Greywacke and a greywacke aggregate (G1) from another quarry in Northland of New Zealand (NZ).

Investigating a skid resistance related crash model for the G4 Auckland greywacke

Methodology

Select roads constructed using G4 Auckland greywacke aggregates from RAMM database

Measure the skid resistance by using Grip Tester

Visually assess the macrotexture

Analyse the in-field results

Compare thefield and laboratory test

results for G4 greywacke aggregate

Compare the performance of G4 and

G1 greywacke aggregates

Relate the G4 greywacke aggregatefield results with crash

numbers

Conclusions and Findings

8

Skid Testing Procedures

2-3 runs Run at 30-40

km/h Calibrated every

2-3 days of skid testings

Seasonal Variations

Northland G1Greywacke Aggregate

Source: http://www.epccn.com/en/productinfo448.html

Source: http://maps.google.com/

SH 11

11

Crash Analysis Methodology

Input

Map

Define

Report

Crash Data Analysis

Exposure Relative Crash Rate

Laboratory versus Field Performance

0 1 2 3 4 50.00.10.20.30.40.50.60.70.8

Time in Polishing (hours)

Dyn

am

ic F

rict

ion

Test

er

(μ)

0 1 2 3 4 5 6 7 8 9 10 11 120

0.10.20.30.40.50.60.70.8

Surface Age (year)

Gri

p N

um

ber

(GN

)Laboratory

Results (Kumar, 2009)

Field Results

Laboratory and Field Performance

1 2 3 4 5 6 7 8 9 10 11

Se-ries1

0.4

0.45

0.5

0.55

0.6

0.65

0.7

0.75

0.4

0.45

0.5

0.55

0.6

0.65

0.7

0.75

Surface Age (year)

GN

Polishing Time (hours)

DFT (

µ)

Macrotexture

Good

Medium

Poor

Traffic Polishing

0 100000 200000 300000 400000 500000 600000 7000000

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

GN Against %HCV

ADT 100-500ADT 501-2000ADT 2001-4000ADT 4001-10000

Surface Age x ADT x %HCV (105)

Gri

p N

um

ber

(G

N)

Northland Greywacke Aggregates

0 1 2 3 4 5 6 7 8 9 100

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

f(x) = − 0.0190330053259258 ln(x) + 0.472939843470488R² = 0.103194690412337f(x) = 0.470786123463245 x^-0.0453690062716688R² = 0.110997197696856

Age

SC

RIM

0 1 2 3 4 5 6 7 8 9 10 11 120

0.10.20.30.40.50.60.70.8

Surface Age (year)

Gri

p N

um

ber

(GN

)

0 0.5 1 1.5 2 2.5 30

0.10.20.30.40.50.60.70.8

PoorMediumGood

Macrotexture

SC

RIM

Crash Analysis Results

65%

35%

Crash OccurrencesNo Crash Sites Crash Sites

18

89%

11%

Crash FactorsOther Crash TypesLoss of Control and Wet Surface Crashes

Relative Crash Rate Against Skid Resistance

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.80

1

2

3

4

5

f(x) = 157267.276177605 exp( − 25.1247211917621 x )R² = 0.88454829027296

Grip Number (GN)

Rela

tive C

rash

R

ate

0.45 0.47 0.49 0.51 0.53 0.55 0.57 0.590

0.2

0.4

0.6

0.8

1

f(x) = 157267.276177605 exp( − 25.1247211917621 x )R² = 0.88454829027296

Grip Number (GN)

Rela

tive

Cra

sh

Rate

Conclusions

The accelerated laboratory polishing prediction methodology developed at UoA by Wilson (2006) can adequately reflect the field performance as measured by the GT for G4 and by the SCRIMM++ for G1

The relative crash rate decrease exponentially with increasing skid resistance.

Macrotexture and microtexture measurements are important to adequately describe skid resistance field measurements

Further Research Directions

Analyse single coat seal and asphaltic concrete type pavements

Extend the analysis to different road categories

Extend crash analysis to different aggregates types

Analyse geometrically variable road sections

Jayden Ellis (Stevenson Ltd)Barry Larsen (Stevenson Ltd)Ross Ashby (Stevenson Ltd)Noel Perinpayagam (The University of Auckland)Sujith Jose Padiyara (The University of Auckland)Si Thu Win (Downer EDI)

Acknowledgements

MAIREPAV 7 Conference, Auckland, NZ - Call for Abstracts now open….

AUCKLAND, NEW ZEALAND – AUGUST 27-30, 2012

MAIREPAV 7 Conference, Auckland, NZ - Call for Abstracts now open….

27-30th August 2012