Roads/Highways

The Logit Model and the Need to Reproduce the Stiffness Degradation Curve of Asphalt Specimens During Fatigue Testing

Angel Mateos
Wu, Rongzong
Harvey, John
Denneman, Erik
Fan, Angela
2017

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...

Support for Superpave Implementation: Round Robin Hamburg Wheel-Track Testing

Angel Mateos
Jones, David
2017

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...

Development of Improved Guidelines and Designs for Thin Whitetopping: Construction and Initial Environmental Response of Full-Scale BCOA Sections

Angel Mateos
Harvey, John
Paniagua, Fabian
Paniagua, Julio
Wu, Rongzong
2018

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...

Mechanical Characterisation of Concrete-Asphalt Interface in Bonded Concrete Overlays of Asphalt Pavements

Angel Mateos
Harvey, John
Paniagua, Julio
Paniagua, Fabian
Fan Liu, Angela
2017

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...

Mechanistic-Empirical (ME) Design: Mix Design Guidance for Use with Asphalt Concrete Performance-Related Specifications

Wu, Rongzong
Harvey, John
Buscheck, Jeff
Angel Mateos
2018

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...

Evaluation of the Effect of Deflection Waveform on Fatigue Test Results for Hot Mix Asphalt

Angel Mateos
Wu, Rongzong
Denneman, Erik
Liu, Angela
Harvey, John
2017

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....

Accelerated Testing of Full-Scale Thin Bonded Concrete Overlay of Asphalt

Angel Mateos
Harvey, John
Paniagua, Fabian
Paniagua, Julio
Wu, Rongzong
2019

A research study was conducted with the goal of determining the expected performance life of thin bonded concrete overlay of asphalt (BCOA) in California. Eleven thin BCOA sections were built and tested with the Heavy Vehicle Simulators (HVS) in Davis, California. The performance of the sections in the HVS testing provided insight into the mechanics of the thin BCOA structures and the effects the different rapid-strength concrete materials, traffic, jointing, and base factors on their performance, including testing in both very wet and very dry conditions. Overall, the performance of the...

Sine versus Haversine Displacement Waveform Comparison for Hot Mix Asphalt Four-Point Bending Fatigue Testing

Angel Mateos
Wu, Rongzong
Denneman, Erik
2018

An experimental study was conducted to determine the effect of haversine and sine displacement waveforms on four-point flexural beam fatigue test results for hot mix asphalt. Seven asphalt mixtures with different gradations, binder types, and binder contents were tested for this study. Four of the mixes were tested in California and three in Australia. The mixes were tested at different strain levels under both waveforms in displacement-controlled mode without rest periods. The comparison showed no differences between haversine and sine testing modes for six of the seven mixtures. Fatigue...

Evaluation of Mix Designs for Rapid Construction of Bonded Concrete Overlays on Asphalt

Fernandez, Julio Paniagua
Fernandez, Fabian Paniagua
Harvey, John
Angel Mateos
2018

Road users in California have a low tolerance for delays during pavement rehabilitation. Therefore, the California Department of Transportation (Caltrans) is interested in evaluating bonded concrete overlays on asphalt (BCOA) as a potential rehabilitation alternative for distressed asphalt pavement. The use of high early strength concrete to facilitate rapid construction of BCOA has not been used in other U.S. states. This paper summarizes a complete study for the evaluation of concrete mix designs for rapid construction of BCOA that were placed on a set of full-scale test sections for...

Field Evaluation of the Impact of Environmental Conditions on Concrete Moisture-related Shrinkage and Coefficient of Thermal Expansion

Angel Mateos
Harvey, John
Bolander, John
Wu, Rongzong
Paniagua, Fabian
Paniagua, Julio
2019

This study evaluates the impact of the environmental conditions on the moisture-related shrinkage and the coefficient of thermal expansion (CTE) of concrete. The evaluations are based on the strain measured in a series of unrestrained shrinkage prisms during fifteen months. The prisms included four concrete mixtures containing either portland cement or calcium sulfoaluminate cement. The prisms were fabricated in the field and left outdoors so that they were subjected to natural rainfall, sun radiation, and daily and seasonal changes in air temperature and relative humidity (RH). A strain...