Four-point bending fatigue tests following the Strategic Highway Research Program (SHRP) M009 test protocol were executed to investigate to what extent gradation has an effect on fatigue performance of asphalt aggregate mixes. Gradations and mixes were selected that would satisfy all volumetric Superpave designs passing below the restricted zone. Other mixes were prepared with gradations passing through and above the restricted zone. The measured fatigue lives of 130 actual laboratory tests were compared with predictions by the Shell, Asphalt Institute, and SHRP-A003A fatigue-predictive equations.The fatigue life of an asphalt concrete mixture is influenced by several factors, such as bitumen type and content and air-void content. Others factors, such as temperature, frequency, and rest periods of applied loads, as well as other material properties, may also affect fatigue life. Although the influence of binder type and content has been studied extensively, the effect of some aggregate properties, such as the aggregate gradation, has not been widely presented.Superpave volumetric mix designs (previously referred to as Level I in the research documents) select a binder content and a gradation that are dictated by the behavior of the mix at compacting temperatures in the gyratory compactor. No performance-based tests are executed on the mix to evaluate its behavior at in-service temperatures.In the process of evaluating the possibility of adopting the Superpave volumetric mix design procedures in Portugal, the road administration (Junta Autónoma de Estradas) investigated to what extent mixes proposed by the Superpave volumetric procedure are superior in performance to other mixes. For that evaluation process, one of the tools used in comparing mixes was the determination of fatigue life using the Strategic Highway Research Program (SHRP) M009 four-point bending fatigue test. Fatigue performance needs to be evaluated to prevent dense-graded mixes from being too "dry," because that could lead to premature fatigue failures. Furthermore, criteria are needed to evaluate the performance of mixes to be placed on structural fatigue-resistant layers.The gradations proposed by the Superpave volumetric design procedures generally pass below the restricted zone. For comparison purposes, other gradations were selected that pass through and above the restricted zone. The other gradations were selected on the basis of standard specifications used by some highway agencies. As such, gradations were selected that would satisfy (or at least come
The dietary transition from traditional to commercial foods and a decrease in physical activity (PA) have impacted the health of the First Nations people of Quebec (Canada), resulting in many suffering from multiple chronic diseases. This study had two objectives: (1) to examine eating and PA behaviors among First Nations peoples in urban areas and (2) to explore the associated health representations. To achieve these objectives, a mixed-methods approach, including a questionnaire (n = 32) and a semi-structured interview (n = 14), was used to explore the participants’ lifestyle profiles and health experiences. The questionnaire focused on the eating and PA behaviors of First Nations people and their underlying motivations. At the same time, the interviews investigated their health views on diet and PA behaviors based on the conceptual framework of health and its determinants. According to the participants, health is the autonomy to live without pain by maintaining a balance between physical and psychological aspects, eating healthy and exercising. Family and work influence participants’ PA and eating behaviors. Exploring First Nations people’s beliefs and perceptions and the motivations underlying their health behaviors could help encourage the maintenance of a healthy lifestyle despite multiple chronic health conditions.
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.