Asphalt fatigue cracking is widely recognized as one of the most important pavement distresses, which is typically evaluated in the laboratory by conducting repeated load fatigue tests. There is no simple model that can fully reproduce the evolution of the stiffness of asphalt specimens during fatigue testing. This reality limits analysis and interpretation of asphalt fatigue data and the implementation of test results in mechanistic–empirical modeling. Two simple models, based on the logit function, are presented in this paper. These models, called logit and logit-sigmoidal, were found to...
Bonded Concrete Overlay of Asphalt (BCOA) are being investigated for rehabilitation of asphalt pavements in California’s dry climate as part of a cooperative project led by the University of California Pavement Research Center for California Department of Transportation. Heavy Vehicle Simulator (HVS) is going to be used to evaluate future performance and develop a design and construction guide for Caltrans. This paper consists in a design of an Accelerated Pavement Testing (APT) test track for analyzing the performance of the BCOA structures under the use of a HVS. Besides it summarizes...
Thin whitetopping, also known as thin bonded concrete overlay on asphalt (BCOA), is a rehabilitation alternative consisting of a 0.33 to 0.58 ft (100 to 175 mm) thick portland cement concrete (PCC) overlay of an existing flexible or composite pavement. It has been frequently used in different U.S. states and in other countries in the Americas, Europe, and Asia. This technical memorandum constitutes the literature review for Partnered Pavement Research Center Strategic Plan Element (PPRC SPE) Project 4.58B, whose primary goal is to develop recommendations and guidance on the use of thin...
Bonded Concrete Overlay of an Asphalt pavement (BCOA) is a rehabilitation technique consisting of 50–175 mm thickness portland cement concrete overlay on an existing flexible, semi-rigid or composite pavement. This technique, that has also been known as thin (minimum 100 mm) or ultrathin whitetopping (thinner than 100 mm) in the past, relies on the composite action of the concrete and asphalt layers acting together with a third phase of the system being the interface between the two materials. For this study, the stiffness and strength/fatigue resistance of this interface have been...
Internationally, full-scale accelerated pavement testing, either on test roads or linear/circular test tracks, has proven to be a valuable tool that fills the gap between models and laboratory tests and long-term experiments on in-service pavements. Accelerated pavement testing is used to improve understanding of pavement behavior.
A round robin testing program was undertaken between 20 participating laboratories in California to assess the reproducibility of Hamburg Wheel-Track (HWT) test results as part of a Superpave implementation initiative. Each laboratory conducted four HWT tests. Two of the tests were conducted on gyratory-compacted specimens prepared by the University of California Pavement Research Center (UCPRC), and the other two were conducted on gyratory-compacted specimens prepared by each of the participating laboratories using loose mix supplied by the UCPRC. A three-quarter inch mix with five...
Thin bonded concrete overlay of asphalt (BCOA) is a rehabilitation alternative consisting of a 100 to 175 mm (0.33 to 0.58 ft) thick portland cement concrete (PCC) overlay of an existing flexible or composite pavement. Fifteen BCOA sections were built at the Davis facilities of the University of California Pavement Research Center in February 2016. Eleven of these full-scale sections were tested under accelerated loading, while four of them were used for monitoring the response of BCOA to the ambient environment and cement hydration. This full-scale experiment is part of a research project...
Bonded concrete overlay of an asphalt pavement (BCOA) is a rehabilitation technique consisting of 50–175 mm thickness concrete overlay on an existing asphalt pavement. This technique, known as thin (minimum 100 mm) or ultra-thin whitetopping (thinner than 100 mm) in the past, relies on the composite action of concrete and asphalt layers acting together with a third phase of the system being the interface between the two materials. For this study, the stiffness and strength/fatigue resistance of this interface have been characterised by means of a series of laboratory tests conducted on...
Caltrans has adopted mechanistic-empirical (ME) methods for flexible pavement design, and is using performance-related construction specifications on some projects for hot mix asphalt. Performance-related specifications are used to help ensure that as-built materials meet the performance requirements assumed in ME pavement structural designs. PRS pose new challenges for materials producers and contractors who have never had to relate volumetric mix design parameters to achievement of mechanistic parameters for fatigue life and rutting resistance based on results from performance-related...
An experimental study was conducted to determine the effect of deflection waveform on four-point flexural fatigue test results for hot mix asphalt. Seven asphalt mixtures, comprising a wide variety of gradations, binder types, and binder contents, were selected for this study. Four of the mixes were tested at the University of California Pavement Research Center (UCPRC) and three were tested in Australia by the ARRB Group. The mixes were tested at different strain levels under both haversine and sinusoidal deflection-controlled modes without introducing rest periods between load cycles....
