A REVIEW OF LONG TERM PAVEMENT PERFORMANCE …

27th ARRB Conference – Linking people, places and opportunities, Melbourne, Victoria 2016

© ARRB Group Ltd and Authors 2016 1

A REVIEW OF LONG TERM PAVEMENT PERFORMANCE MONITORING IN WESTERN AUSTRALIA

Hossein Asadi, Kieran Sharp and Jonathon Griffin, ARRB Group, Australia

ABSTRACT

This paper presents a summary of the study carried out by ARRB for Main Roads Western Australia (MRWA) to select appropriate long term pavement performance (LTPP) section for their inclusion in Austroads LTPP database. To select appropriate LTPP monitoring sites, when roughness and strength were used as the major performance indicators, a total of six potential LTPP sites were identified. A review of available data pertaining to three roads (Great Northern Highway, Marble Bar Road and Ripon Hills Road) – including pavement composition, pavement repair history and traffic data – and a review of available pavement condition data and its alignment with recommended criteria (limits) of roughness, rutting and maximum deflection data, resulted in the identification of only one site which met all the criteria in terms of roughness, rutting and strength. Recommendations are also made regarding the value continuing to monitor the identified trial sections or, if deemed unsatisfactory, to construct and monitor new trial sections.

INTRODUCTION

The main objective of long term pavement performance (LTPP) studies is to evaluate and improve current pavement design and management strategies by assembling broad information regarding the performance of in-service pavements for a range of materials, traffic loading, climates and maintenance activities. Generally, such studies involve the monitoring of the performance of pavements from the day they are opened to traffic for a minimum of five years and preferably for the perceived life of the pavement (up to 20 years). Several significant LTPP studies have been conducted by Main Roads Western Australia (MRWA) over the last 20 years – including work conducted as part of the US Strategic Highway Research Program (SHRP) and a current project which has been sponsored by Austroads since 1995.

However, whilst MRWA has been monitoring the performance of various pavement types since at least the late-1970s, many of the MRWA trials have been ad hoc in nature and no sites are currently included in the Austroads LTPP project or the Austroads LTPP/LTPPM database. To expedite the inclusion of WA pavements into the Austroads LTPP research project, it was proposed, as a first step, that three sprayed seal granular pavements be identified based on a review of data contained in MRWA’s IRIS database, and other relevant sources, and that initial data be input into the Austroads LTPP/LTPPM database. If, on the other hand, it was determined that none of the current sites were, for a variety of reasons, suitable for inclusion in the Austroads database, then consideration be given to the establishment of new sites which met the criteria for inclusion in the database. This paper aims to summarise the previous attempts by MRWA for LTPP monitoring and also provides some guidelines on selection of most suitable LTPP trials.

BACKGROUND

US Strategic Highway Research Program (SHRP)

In early 1980, a comprehensive research program involving the monitoring of the deterioration of the highway and bridge infrastructure in the USA commenced. The work was funded and coordinated by the Transportation Research Board (TRB), under the auspices of the Federal Highway Administration (FHWA) and the American Association of State Highway and Transportation Officials (AASHTO). As a result of this project, it was decided to incorporate an



LTPP element into the US Strategic Highway Research Program (SHRP) which commenced in 1987 and ran until 1992. At the completion of SHRP in 1992, it was agreed that the LTPP element of the program needed to continue. As a result, the project was transferred to the FHWA. An LTPP committee was formed to manage the LTPP program in 1995 (TRB 2009).

The study includes two fundamental procedures: General Pavement Studies (GPS) and Specific Pavement Studies (SPS). In both procedures information regarding pavement performance indicators, deterioration, structural capacity, temperature and moisture is being collected.

The pavement types being monitored under the GPS are as follows (FHWA 2014a):

GPS1: asphalt on granular base

GPS2: asphalt on bound base

GPS3: jointed plain concrete pavement (JPCP)

GPS4: jointed reinforced concrete pavement (JRCP)

GPS5: continuously reinforced concrete pavement (CRCP)

GPS6: asphalt overlay of asphalt pavement

GPS7: asphalt overlay of PCC

GPS8: discontinued

GPS9: unbound PCC overlays on PCC pavements.

The components of the SPS element of the project are as follows (FHWA 2014b):

SPS1: strategic study of structural factors for flexible pavements

SPS2: strategic study of structural factors for rigid pavements

SPS3: preventive maintenance effectiveness of flexible pavements

SPS4: preventive maintenance effectiveness of rigid pavements

SPS5: rehabilitation of asphalt pavements

SPS6: rehabilitation of jointed PCC pavements

SPS7: bonded PCC overlays on concrete pavements

SPS8: study of environmental effects in the absence of heavy loads

SPS9: validation of SHRP asphalt specification and mix design (Superpave – Superior Performing Asphalt Pavements).

Details of the program, including accomplishments and benefits are presented in FHWA (2010).

Austroads LTPP Project

In 1994 Austroads commissioned a research project to monitor the long-term pavement

performance (LTPP) of typical Australian in-service pavements. The main objective is to

monitor the long term structural and functional performance of a range of in-service pavements

including sealed granular, asphalt, cemented-treated and concrete pavement sections under

different climate and traffic loading regimes.

The two components of the project are:

the development of nationally consistent pavement performance models for use at both the network and project levels (LTPP program) – in conjunction with the US-SHRP program, the monitoring of 19 trial sections with different pavement configurations, including flexible and rigid pavements Australia-wide, and sections previously subjected to accelerated pavement testing (Choummanivong & Martin 2010)

the influence of maintenance activities on long-term pavement performance (LTPPM program) – the monitoring of eight trial sections in Victoria, NSW, Queensland and Tasmania



under different climatic and traffic loading conditions and maintenance strategies (Choummanivong & Martin 2010).

In 2001, the decision was taken to combine these programs for the purposes of cost efficiency,

with the data merged into one database (LTPP/LTPPM database).

A series of reports has been produced addressing the development of road deterioration (RD)

models for all types of performance parameters, viz. roughness, rutting, cracking, and strength.

More recently, the study has been extended to include a probabilistic modelling approach to

account for uncertainties in the process.

The data collected from the LTPP and LTPPM sites through annual condition surveys has been compiled in a single database and posted on the LTPP website <http://www.arrb.com.au/ltpp/>. It is available to Austroads members, researchers and the general public.

Other Studies in Western Australia

This section summarises the studies carried out on three LTPP sites known as Gogo, Tonkin Highway 357–3 and Kwinana Freeway trials.

Gogo Trial Sections

Thirteen sections were established during October-November in 1982 (MRWA 1994). The road base materials were naturally-occurring laterites and calcretes which do not comply with standard specifications. Details of the trial sections are presented in Table 1 whilst the approximate location of the trials is shown in Figure 1.

Table 1: Details of trial sections at Gogo

Section no.

SLK range Material type

Construction technique

Surfacing

1 2544.50–2545.00 Calcrete Normal 9 mm primer seal




5 2546.50–2547.00 Calcrete Stage construction Nil

6 2547.00–2547.50 Laterite Stage construction Nil

7 2547.50–2548.00 Laterite Normal 9 mm primer seal

8 2548.00–2548.50 Laterite Slurry seal 9 mm primer seal





13 2550.50–2551.00 Laterite Normal, with Calgon added to water

9 mm primer seal



Figure 1: Approximate location of Gogo trials.

The performance of all 13 sections after 11 years of monitoring was generally satisfactory, with little loss of pavement shape. Based on the observed good performance, it was concluded that local laterites and calcretes were suitable for use as a basecourse in regions with a similar climate to Gogo, even though they do not comply with standard specifications or guidelines.

Tonkin Highway 357–3 trials

ARRB Project 357, ‘Field Trials of Pavement Structures’ was established by Austroads (then NAASRA) in the late 1970s. The principal aim of the project was to obtain measurements from trial sections during construction and under service conditions and, in conjunction with associated laboratory testing, to define the behaviour and performance of asphalt and other layers (particularly granular layers) in terms of their structural design parameters and/or granular equivalencies. At that time, the concept of ‘materials equivalency’ was being investigated as a possible means of comparing the behaviour/performance of one pavement type with that of another. It was also in the era when the use of asphalt in pavements was starting to be seriously considered as an alternative to the traditional unbound pavement with thin bituminous surfacing.

State road agencies (SRAs) in each mainland state constructed trial sections as their contribution to the project; some states, including WA, installed additional sections in order to address local requirements and conditions. Emphasis was on the relative structural performance of the test pavements as input into (then) current pavement design procedures. There was no network level component of the project; however, as discussed later, the possibility exists to seek out more recent pavement condition data (roughness, etc.) in order that it can be used to further calibrate the pavement deterioration models developed during the current Austroads project. One of the tasks associated with this project was the preparation of a series of reports documenting the construction of the test sections in each state, and any associated field and laboratory testing conducted during construction, this data to be supplied by the various SRAs. The summary construction report for WA was issued as an ARRB Internal Report in 1987 (Sharp et al. 1987), although the sites had been constructed in 1980 and 1982. Full details of the construction and associated testing are available in a series of MRWA internal reports (Butkus and Bruce 1982a and b; 1983a, b, c, d and e; Butkus 1983).

Kwinana Freeway trials

In order to investigate and assess the performance of pavements comprised of different types of wearing course and basecourse materials placed on generally uniform subbase and subgrade materials, 15 trial sections, each 100 metres long, were constructed on the Kwinana Freeway from SLK 55.18 to SLK 56.68 in 2009.

Approximate location of GOGO trials

(SLK 2544.50 to 2551.00)



The aim of the investigation is to monitor the pavement performance of different trial sections over a period of time to assist in gaining a better understanding of the behaviour of pavement materials subject to known traffic loading and to use the findings to improve pavement design and specifications.

The trials are part of the New Perth Bunbury Highway project (NPBH) which is a continuous 70.5 km long dual carriageway from Safety Bay Road in Baldivis to Old Coast Road in Lake Clifton. The 32 km long section from Safety Bay Road in Baldivis to South Yunderup Road, South Yunderup comprises an extension to the Kwinana Freeway. The remainder of the route, the Forrest Highway, is a rural highway. In order to monitor the performance of the trial sections, various tests have been conducted since construction, including Falling Weight Deflectometer (FWD) deflection testing, rut depth and visual assessment. A summary of the data is presented in Rehman (2013).

ESTABLISHING LTPP SITES IN WESTERN AUSTRALIA

The selection criteria for establishing new LTPP sites are described in more detail in the site establishment guidelines (Clayton 2000). They can be briefly summarised as follows:

Consideration of pavement composition and availability of materials testing information

availability of construction and maintenance activity records

suitability of alignment, i.e. without sharp curves and longitudinal grade less than about 2%

minimum length of 200 m

consistency of subgrade conditions

availability of traffic volume (and ideally axle load and configuration) data

practicality and safety issues

availability of historic pavement performance and maintenance records (preferably).

Selection of WA LTPP Sites

The first step in the selection process was a review of the available data in MRWA database,

including the criteria listed above. It was determined that, for a variety of reasons (mainly a lack

of relevant data, although some sites were no longer in commission and/or no longer existed,

etc.) none of the sites were suitable. It was also decided that sprayed seal granular pavements

should be targeted for inclusion in the LTPP program. Attention then turned to the project then

being conducted by ARRB for MRWA under the WAPARC program, viz. Marginal Wear Costs of

Increased Axle Mass (Asadi & Cocks 2014). The emphasis in that project was whether there

was sufficient cost recovery regarding the additional costs of heavy vehicles operating at 23.5

tonnes hauling ore along the road network in the Pilbara. Network performance data was not

analysed. As a result, and following discussions with MRWA, three sprayed seal granular

pavement sections were selected, details of which are provided in Table 2.

Table 2: Pavement sections nominated for LTPP monitoring

Road Road type SLK1 range Year

constructed

Length of

section (km)

Base

material

Great

Northern Hwy

Two lane, single

carriageway

1577.03–

1583.61 1974 6.58 Gravel

Marble Bar

Road

Two lane, single

carriageway 408.16–421.70 1988 13.54 Gravel

Ripon Hills

Road

Two lane, single

carriageway 10.20–20.65 1999 10.45 Gravel

1 Straight line kilometre

The approximate location of the test sections is shown in Figure 2, while the schematic location

of the nominated sections is shown in Figure 3.



Figure 2: Approximate location of nominated sections (Source: MRWA Integrated Mapping System (IMS) 2014)

Figure 3: Schematic location of nominated sections and SLK for different features

Fundamental to the successful conduct of any LTPP program is the need to know details such as the pavement structure, surface condition, pavement maintenance history, and traffic. The relevant information was extracted from the MRWA IRIS database.

N

1

North West Coastal HWY

Port Hedland

Marble Bar Rd

MINE

PARDOO

MINE

WODGINA

MINE

PHIL’S CREEK

MINE

MT DOVE

LEGENDS

- Traffic Count Sites (Piezo -Permanent)

- Intersections

- WIM Traffic Count Site

- Nominated Section on Great Northern HWY

- Nominated Section on Marble Bar Rd

- Nominated Section on Ripon Hills Rd

SLK 1616.46

SLK 1607.83

SLK 1578.22

SLK 1569.21

SLK 1312.76

MINE

WOODIE WOODIE

Ripon Hills Rd

MINE

SPINIFEX RIDGE

SLK 426.39

SLK 3.98

Great Northern HWY

MINE

ABYDOS

SLK 1543.87

SLK 1507.12

SLK 1357.72

SLK 375.96

SLK 316.07

SLK 130.94

SLK 1649.21 & 433.94 SLK 1719.46

SLK 1577.08

SLK 275.59 & 0.00

SLK 1609.34

SLK 1163.55

LEGEND SLK RANGE

1577.03–1583.61

408.60–421.70

10.20–20.65



Pavement Condition Analysis

The following criteria were recommended when selecting potential LTPP sites:

2.0 IRI ≤ average roughness ≤ 3.0 IRI

4 mm ≤ average rutting ≤ 8 mm

500 microns ≤ maximum deflection (normalised at 700 kPa) ≤ 800 microns

alignment – reasonably straight section for safety reason and slope gradient < 3%.

Potential LTPP Sites Based on Rutting, Roughness and Strength Data

Ideally, the trend in the three performance indicators (roughness, rutting and deflection) over time should indicate that the structural and functional condition of the section is deteriorating over time. On the basis that the trend in all the pavement performance indicators should be an increase over time (i.e. the pavements are deteriorating), then the only potential site that met this requirement was at Marble Bar Road (SLK 411.8 to 412.1). Details of this site are summarised in Table 3.

Table 3: Potential LTPP site: Marble Bar Road (based on roughness, rutting and strength data)

Subsection

ID

SLK

range Year

Roughness

(IRI Lane)

Rutting

(IWP)

(mm)

Rutting

(OWP)

(mm)

Max. FWD

deflection

(microns)

SUB M01 –

LEFT

411.8–

412.1

2007–08 1.05 4.43 7.39 675

2009–10 1.13 5.88 10.03 765

2014–15 1.95 7.99 11.01 836

Potential LTPP Sites Based on Roughness and Strength Data

Rutting was not identified as a serious pavement defect after reviewing the rutting performance history of roads in Pilbara region and in a different scenario only roughness and strength were used as major performance indicators. Based on this, the sites shown in Table 4 were identified as potential LTPP sections. Based on information extracted from IRIS, there was no change in pavement structure (base layer, surface) and maintenance activity in all nominated subsections. It should also be noted that the slope gradient for selected subsections was less than 3%.

Table 4: Potential LTPP sites: Marble Bar Road (based on roughness and strength data)

Subsection ID SLK range Year IRI lane

Max. FWD

deflection

(microns)

SUB G03 – LEFT 1582.23–1582.43

2007–08 1.27 1013

2009–10 1.17 862

2014–15 1.37 894

SUB G03 – RIGHT 1582.23–1582.43

2007–08 1.1 800

2009–10 1.46 826

2014–15 1.87 792

SUB M01 – LEFT 411.8–412.1

2007–08 1.05 675

2009–10 1.13 765

2014–15 1.95 836



Subsection ID SLK range Year IRI lane

Max. FWD

deflection

(microns)

SUB M01 – RIGHT 411.8–412.1

2007–08 1.06 1189

2009–10 1.19 1646

2014–15 2.65 1252

SUB R03 – LEFT 20.32–20.62

2007–08 2.21 440

2009–10 2.45 461

2014–15 2.60 514

SUB R03 – RIGHT 20.32–20.62

2007–08 1.97 558

2009–10 2.18 609

2014–15 2.54 265

CONCLUSION

A review of available data pertaining to three roads (Great Northern Highway, Marble Bar Road and Ripon Hills Road) – including pavement composition, pavement repair history and traffic data (and hence estimated ESAs) – and a review of available pavement condition data and its alignment with recommended criteria (limits) of roughness, rutting and maximum deflection data, resulted in the identification of only one site which met all the criteria in terms of roughness, rutting and strength. When roughness and strength were used as the major performance indicators, a total of six potential LTPP sites were identified as shown in Table 4.

However, none of these sites satisfied all the desired selection criteria. While the sites that have been selected for possible inclusion in a future LTPP project met many of the criteria, they all have some drawbacks in terms of information not currently available, or unlikely to become available, including:

There is no WIM site close to any of the selected sites.

The pavement performance indicators (roughness, rutting and strength) are based on network level surveys which may or may not reflect the condition at the specific subsections, i.e. there is no project level data.

There is no data pertaining to the laboratory characterisation of the pavement materials, e.g. maximum dry density (MDD), CBR, particle size distribution (PSD), moisture content, Atterberg Limits, etc.

There is no detailed maintenance history information.

There is no weather/climatic data; however, most cattle and sheep stations in Western Australia maintain rainfall and temperature records that are accessible via the Bureau of Meteorology.

Considering the highlighted challenges above, it was recommended that new granular pavement sites be established for long-term monitoring with following objectives:

A selection of suitable LTPP trial section(s) to be constructed as part of a planned MRWA project

development of a test plan for the proposed new LTPP trial section(s)

collection of climate, traffic, maintenance and pavement performance data.



REFERENCES

Asadi, H & Cocks, G 2014, ‘Marginal wear costs of increased axle mass: a case study’, report 006379-1, Main Roads Western Australia, Perth, WA.

Butkus, F 1983, ‘Beechboro-Gosnells highway test sections, ARRB project 357, sections 13-15, construction start data’, MRD WA internal technical report 83/85M, November, Main Roads Department, Perth, WA.

Butkus, F 1994, ‘Tonkin Highway, ARRB project 357, monitoring data (May 1981-November 1990 inclusive)’, materials engineering report no. 94/32 M, July, Main Roads Western Australia, Perth, WA.

Butkus, F & Bruce, G 1982a, ‘Beechboro-Gosnells highway test sections, part 1: general description and objectives’, MRD WA internal technical report, 82/20, July, Main Roads Department, Perth, WA.

Butkus, F & Bruce, G 1982b, ‘Beechboro-Gosnells highway test sections, part 2: foundation and subgrade construction start data’, MRD WA internal technical report, 82/21, August, Main Roads Department, Perth, WA.

Butkus, F & Bruce, G 1983a, ‘Beechboro-Gosnells highway test sections, part 3: subbase construction start data’, MRD WA internal technical report, 82/22, March, Main Roads Department, Perth, WA.

Butkus, F & Bruce, G 1983b, ‘Beechboro-Gosnells highway test sections, part 3: basecourse construction start data’, MRD WA internal technical report, 82/23, March, Main Roads Department, Perth, WA.

Butkus, F & Bruce, G 1983c, ‘Beechboro-Gosnells highway test sections, part 4: asphalt construction start data’, MRD WA internal technical report, 82/24, March, Main Roads Department, Perth, WA.

Butkus, F & Bruce, G 1983d, ‘Beechboro-Gosnells highway test sections: sealing aggregate report’, MRD WA internal technical report, 82/25, April, Main Roads Department, Perth, WA.

Butkus, F & Bruce, G 1983e, ‘Beechboro-Gosnells highway test sections: density measurement report’, MRD WA internal technical report, 82/26, March, Main Roads Department, Perth, WA.

Choummanivong, L & Martin, T 2010, Predicting structural deterioration of pavements at a network level: interim models, AP-T159-10 Austroads, Sydney, NSW.

Clayton, B 2000, ‘Guidelines for site establishment and data collection for new long-term pavement performance sites’, contract report RC90256-1, ARRB Transport Research, Vermont South, Vic.

Federal Highway Administration 2010, Long-term pavement performance program: accomplishments and benefits 1989–2009, publication No. FHWA-HRT-10-071, HRDI-13/08-10(1M)E, webpage, US Department of Transportation, Washington, DC, USA, viewed 2 May 2016, http://www.fhwa.dot.gov/publications/research/infrastructure/pavements/ltpp/10071/10071.pdf.

Federal Highway Administration 2014a, Long term pavement performance: general pavement studies, webpage, US Department of Transportation, Washington, DC, USA, viewed 2 May 2016, http://www.fhwa.dot.gov/research/tfhrc/programs/infrastructure/pavements/ltpp/gps.cfm.

Federal Highway Administration 2014b, Long term pavement performance: specific pavement studies, webpage, U.S. Department of Transportation, Washington DC, USA, viewed 2

http://www.fhwa.dot.gov/research/tfhrc/programs/infrastructure/pavements/ltpp/gps.cfm



May 2016, http://www.fhwa.dot.gov/research/tfhrc/programs/infrastructure/pavements/ltpp/sps.cfm.

Harris, D & Lockwood, N 2009, ‘Reid Highway basecourse test sections performance to December 2008 revision of report no. 2004/17 M (Volume 1)’, materials engineering report No 2009/5 M, August, Main Roads Western Australia, Perth, WA.

Main Roads Western Australia 1994, ‘Gogo trial sections Great Northern Highway field assessment and performance from 1982 to 1994’, materials report no. 94/20 M, MRWA, Perth, WA.

Rehman, S 2013, ‘Kwinana Freeway trial sections (SLK 55180 TO 56680) pavement monitoring and performance evaluation (from 2009 to March 2013)’, materials engineering report no. 2013-1M, Main Roads Western Australia, Perth, WA.

Sharp, KG, Butkus, F, Bruce, GR, Cocks, GC & Potter, DW 1987, ‘Field trials of pavement structures: construction report: Western Australia’, ARRB internal report AIR 357-3, ARRB Group, Vermont South, Vic.

Transportation Research Board 2009, Preserving and maximizing the utility of the pavement performance database, LTPP report 2009, TRB, Washington, DC, USA.

AUTHOR BIOGRAPHIES

Hossein Asadi is professional pavement engineer at ARRB Group Ltd. He received his PhD from Curtin University in Australia with a thesis on experimental modelling of asphalt mix performance using enhance laboratory equipment. After obtaining his bachelor's degree, Hossein has gained 10 years postgraduate experience in pavement engineering, soil mechanics and traffic engineering. During this time he has managed and led several pavement projects, traffic projects and surveying teams at national and international levels. He was also involved in a project to develop a fully instrumented road condition survey vehicle for Tadbir Foroud Rah Company (TFR) which was used to develop a proper pavement management system (PMS) for Iran's road network.

Kieran Sharp is currently the Senior Business Manager – Member Engagement – in the Research & Consulting Division of ARRB Group. He has worked on a wide range of pavement, materials and asset management research projects for Austroads, State Road Agencies, the National Transport Commission, industry and the OECD. He was the Manager of the Australian Accelerated Loading Facility (ALF) program during the 1990s. He has been involved with various Austroads and industry-based Project Steering Committees and Reference Groups, and FEHRL and TRB Committees. In 2003, Kieran became the first member of ARRB to receive an Austroads Achievement Award in recognition of his contribution to Austroads activities over the previous 20 years. He is also the deputy-chair of the REAAA Australian Chapter. In 2012, he was elected an Honorary Member of REAAA and in 2013, he was awarded the Roads Australia Award for Technical Excellence.

Jonathon Griffin is a Principal Pavement Engineer in the ARRB Group Ltd. His engagement with the ARRB Group began in January 2013 following service with the US Army Engineer Research and Development Center and Tennessee Department of Transportation in the USA. He has served as a technical advisor, principal investigator, subject-matter expert, independent technical auditor and project leader for a number of research, development, testing and evaluation initiatives. Jonathon received a BSc degree in Civil Engineering from the University of Memphis, an MSc degree in the same from Mississippi State University and is currently working towards a Master of Infrastructure Management degree from the Queensland University of Technology. He is a licensed Professional Engineer (PE) in Tennessee, USA, Registered Professional Engineer of Queensland (RPEQ), Chartered Professional Engineer (CPEng). Jonathon’s technical area of expertise is materials research, design, construction, in addition to maintenance and rehabilitation of both flexible and rigid pavements.

Copyright Licence Agreement



The Author allows ARRB Group Ltd to publish the work/s submitted for the 27th ARRB Conference, granting ARRB the non-exclusive right to:

• publish the work in printed format • publish the work in electronic format • publish the work online. The Author retains the right to use their work, illustrations (line art, photographs, figures, plates) and research data in their own future works The Author warrants that they are entitled to deal with the Intellectual Property Rights in the works submitted, including clearing all third party intellectual property rights and obtaining formal permission from their respective institutions or employers before submission, where necessary.

Documents

A REVIEW OF LONG TERM PAVEMENT PERFORMANCE …