FHWA conducted controlled loading tests on the US-23 test road in hot weather conditions in Ohio. The tests used four tire types in both dual and wide-base configurations, which were fitted on a single unit two-axle truck, maintaining a constant gross vehicle weight. Two pavement sections, one 8 in. (200 mm) and one 4 in. (100 mm) thick, were instrumented with strain gauge rosettes oriented vertically to measure strain traces induced from the passing wheel loads at three speeds and tire inflation pressures. Pavement temperature was monitored with depth during testing as well as wheel track offset distance from the strain sensors. Because of time constraints, only the sensors in the plane parallel to the direction of loading were analyzed, and response data were compared only with linear elastic pavement response models. The as-measured data were processed and evaluated for all rosettes oriented in the direction of loading. Stress relaxation modulus data were used to adjust the pavement modulus to a common temperature and loading time so all measured data could be compared at the same loading conditions. The WinLEA linear elastic model was used to determine the relationship of structural modulus to strain. Lateral offset distributions were determined from measured data to adjust all strains to the offset where maximum strain response is observed in the as-measured data. The adjustments were then applied to the as-measured strain data to make consistent comparisons between tires. Three of the four tire configurations produce nearly equivalent pavement response, which was attributed to similarities between the tire footprint widths.
Pavement recycling techniques are often perceived as only applicable to lower traffic volume roadways. However, recent studies have shown their potential for long service lives in higher traffic volume applications. This study documented the response of an asphalt pavement section, constructed using full-depth reclamation (FDR) and cold central plant recycling (CCPR), on a portion of I-64 in Virginia reconstructed between 2016 and 2019. The pavement section was instrumented and the response was compared with a similarly instrumented pavement section (Section S12) placed at the National Center for Asphalt Technology (NCAT) Test Track in 2012. Previous studies have shown that Section S12 is a long-life pavement and it carried 30 million equivalent single axle loads (ESALs) while showing no evidence of deterioration at the pavement surface or from installed instrumentation. The results from the I-64 Segment II project showed that it had much lower horizontal strain values at the bottom of the asphalt layers but slightly higher vertical pressure values on top of the subgrade when compared with NCAT Section S12. Despite the slightly higher values (about 1 pounds per square inch [psi] difference), the vertical pressure on top of the subgrade was very low for both pavement sections. The study confirmed that a recycled pavement section could be constructed and result in low strain and pressure values and is expected to have a long service life in a high traffic volume environment.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.