Geophysical evaluation of flexible and rigid pavement using GPR technique

Dissertant

Mustafa, Ammar Muhammad

Thesis advisor

Karim, Husayn Hamid

University

University of Technology

Faculty

-

Department

Department of Building and Construction Engineering

University Country

Iraq

Degree Date

2013

English Abstract

Ground Penetrating Radar (GPR) is frequently used in pavement engineering for road pavement inspection.

The main objective of this work is to validate nondestructive, quick and powerful measurements using GPR for assessment of Flexible and Rigid pavement conditions.

In the present study, three different antennas (250, 500 and 800 MHz) were used.

The work was achieved by different stages in selected sites.

Severalapplications were carried out: pavement’s layer thickness estimation and pavement evaluationrepresented by the detection and diagnosis of steel reinforcement, cork sheet and plastic pipes.

Two case studies are presented in two sites: the first was carried in University of Technology over about 1250 m of paved road.

In this site, firstly 2D electrical resistivity imaging (ERI) using wenner and wenner-schlumberger array was carried out along two lines, with length survey of40, 60 m respectively;ERI was applied to have an idea about resistivity values that around 30 ohm.m for topsoil,which are suitable for the present study as it deals with very shallow investigation represented by this inspection.

Later, different operating setting parameters were tested including, the suitable antenna and EM wave velocity, the best Maximum Time Window and Point Interval.Also, a core has been extracted from this site and a simulated with GPR.

While in the second site, in-situ simulation model (1.2 m* 1.2 m in dimension) consisting of three layers (sub-base, concrete pavement and asphalt overlays with known standard thicknesses) was made in Canal Amusement Park in Baghdad which had been surveyed by GPR along 16 profiles using three antennas.A simulation was made through validation by checking the thicknesses of these layers with those that can be estimated using GPR.

The interpretation results of the 1st site showed that with 250 MHz antenna, the buried plastic pipe and the flexible pavement layerswere identified.

The later appeared as one layer without identifying the rigid pavement layer.

With 500 MHz antenna, the plastic pipe, rigid pavement, steel reinforcement bars andjoint sheet cork appeared clearly.

Moreover, the short type of max.

time window using antenna 800 MHz appeared to be the most suitable for detecting some road anomalies (plastic pipe, cork heet and reinforcement bars and pavement thickness) which were clearly defined.

For in-situ simulation model at the 2nd site, the interpretation results of 250 MHz antenna identify and assign the overlay as one layer without identifying the rigid pavement layer.

With the 500 MHz antenna, the flexible over rigid appeared as one layer with identifying the rigid pavement boundaries.

While using 800 MHz antenna, both flexible pavement and rigid pavement layers were clearly identified as in the in-situ simulation model.

Main Subjects

Engineering & Technology Sciences (Multidisciplinary)

• APA
• MLA
• AMA

Language

English

Data Type

Arab Theses

Record ID

BIM-417581