QUALITY
CONTROL AND QUALITY ASSURANCE OF
ASPHALT
MIXTURES
H. I. Al-Abdul Wahhab
Professor,
Department of Civil Engineering,
King Fahd University of Petroleum and Minerals
Abstract
The
Gulf
Countries (GC) have undergone an extremely
rapid rate of development in many directions. Therefore, most of the
Gulf Countries have developed more rapidly than many other industrialized
countries. Due to the availability of relatively low cost asphalt binders,
roadway networks in these countries are being built with flexible pavements.
Over the past two decades, a massive construction program to modernize and
improve the region’s highway networks has been initiated. Roads are designed to
the best international standards for service life of 15 to 20 without any major
maintenance. In spite of that, during the past few years some of these roads
have experienced excessive failures such as rutting, raveling, depressions and
fatigue cracking at early stages of pavement’s life. The rate of deterioration
of these pavements has been augmented by the increasing traffic volume, axle
loads, tire pressure, lack of good quality materials, high water table, harsh
environmental conditions, and lack or insufficient quality control and assurance
practices.
The quality of the asphalt concrete materials and construction
methods play a significant role in the performance of the entire pavement
structure. Specifications set forth by road agencies require asphalt materials
to have a specified tolerance by specifying and controlling some of their
important physical properties. This was done to minimize inferior performance
of pavement structures in the field. Although there is similarity between many
attributes of the different specifications, the specified material properties
however are variable. Detailed Quality Control and Quality Assurance (QC/QA)
specifications for asphalt concrete are practiced by some road agencies to
control asphalt concrete materials and construction procedures variability. Some
agencies have even specified some method of pay adjustment. These procedures
have gained wide popularity since the historic
The main objective of this paper is to present statistical
QC/QA methods for the control of asphalt concrete construction.