This paper evaluates the fracture properties of mixtures subjected to different short-term ageing conditions obtained from semi-circular bending test. Response Surface Method (RSM) was used to develop an experimental matrix based on the central composite design. Ageing temperature, ageing duration and duration in humidity and ultraviolet chamber were selected as short-term ageing parameters, while fracture toughness or stress intensity factor (K), broken aggregate (BA) and adhesion failure (AF) were regarded as responses. Image analysis technique was employed for quantification of failures (including adhesion and cohesion failures) on the fractured surface of mixtures. The susceptibility of mixtures’ fracture properties to temperatures was also determined in terms of KTS. The responses were analysed using RSM. The results showed that ageing temperature and ageing duration were the dominating ageing factors affect responses. Ageing increment resulted in higher K and BA while exhibited contradictory effects on AF. Test temperature increment reduced the fracture toughness. The KTS was increased at higher temperatures. Lastly, RSM and image analysis technique exhibited great reliability and capability to study the behaviour of the responses exposed to various ageing conditions.

Several factors affect asphalt binder and mixture characteristics. This makes pavement performance assessment a mounting task. This paper evaluates the effects of short-term aging on compactibility and volumetric properties of asphalt mixtures using the Response Surface Method (RSM). Three different binders were utilized to produce mixtures (type AC-14). Aging temperature, aging duration, and duration in a climate chamber with increased humidity and ultraviolet lighting were considered as independent variables (IV), while compactibility and volumetric properties were regarded as dependent variables (DV). The findings revealed significant impacts of aging temperature and duration on compactibility, air voids, voids in mineral aggregate, and voids filled with asphalt, while duration in the climate chamber exhibited no significant influence on the DVs. The effects of IVs on DVs varied by binder type. This was achieved through an elaborate statistical analysis. The study, finally, demonstrates the RSM’s potential to predict changes in responses from mathematical equations—converging with the experimental observation—with excellent accuracy. Potentially, pavement contractors can use this method by replacing haulage duration and mixtures’ temperatures during paving in the developed models. It enables them to predict the pavement density and adjust pressure as well as the number of roller passes to achieve the desired requirements.