In a short time, the COVID-19 pandemic turned into a global emergency. The fear of becoming infected and the lockdown measures have drastically changed people's daily routine. The aim of this study is to establish the psychological impact that the COVID-19 pandemic is entailing, particularly with regards to levels of stress, anxiety and depression, and to the risks of developing Post-Traumatic Stress Disorder (PTSD). The study, carried out with a sample of 1612 subjects distributed in seven countries (Australia, China, Ecuador, Iran, Italy, Norway and the United States), allowed us to collect information about the psychological impact of COVID-19. The findings of this study show that the levels of stress, depression and anxiety, as well as the risks of PTSD, are higher than average in over half of the considered sample. The severity of these disorders significantly depends on gender, type of outdoor activities, characteristics of their homes, eventual presence of infected acquaintances, time dedicated to looking for related information (in the news and social networks), type of source information and, in part, to the level of education and income. We conclude that COVID-19 has a very strong psychological impact on the global population. This appears to be linked to the coping strategies adopted, level of mindful awareness, socio-demographic variables, people's habits and the way individuals use means of communication and information.

This paper presents a 2-year review and an evaluation of the performance of fiber-reinforced polymer-modified asphalt concrete (FPMAC). A comparison is made of its characteristics with polymer-modified asphalt concrete (PMAC) through laboratory experiments and field observations. Polymers are believed to enhance the binding properties of the asphalt pavements to increase their engineering properties. Some researchers and highway agencies in the cold regions have considered adding fibers in the currently used polymer-modified asphalt concrete to produce FPMAC to be used in pavement construction. FPMAC has the potential to enhance asphalt pavement properties, such as increasing stiffness, resistance to deformation, and stability. An asphalt paving project made of PMAC and FPMAC was implemented in Flagstaff, Arizona, with a goal of evaluating the effect of fiber reinforcement in the performance enhancement of FPMAC. FPMAC and PMAC samples were collected at the job site and shipped back to the materials laboratories at both Northern Arizona University and Arizona State University for experimentations. Throughout the thermal cracking tests and dynamic modulus tests, all data indicated that FPMAC has better performance. After 2-year field visits, FPMAC has showed fewer cracks (with accumulative crack length of 11.2 ft) as compared with PMAC (with accumulative crack length of 123.2 ft). FPMAC has successfully demonstrated its abilities to resist thermal cracking, freeze–thaw cycling, and rutting deformation.

This paper evaluates the cracking mechanism and material characteristics of rocklike specimens under five loading rates (0.02, 0.06, 0.10, 0.14, and $0.18\mathrm{mm}/\mathrm{s}$ ). The rocklike cylinder specimens were prepared and mixed using river sand (as aggregate sources) and cement, gypsum, and starch (as binders). Uniaxial compression tests associate with binarization imaging processing were carried out using the five loading rates to evaluate the cracking propagations and characteristics of rocklike specimens. The results show that with the increase in the loading rate, the peak tensile and compressive strengths of the rocklike specimen increases. The relationship between the ratio of stress to peak stress, and the five loading rates of the rocklike specimen can be expressed as a natural logarithm model while the relationship between the initial crack length of the rocklike specimen and the five loading rates can be represented by as an exponential function. The average rate of crack propagations increases exponentially as the loading rate increases. Based on all test and analysis results and, the paper concludes that the characteristics of cracking mechanism, propagations, and characteristics of rocklike materials show the similar mechanical behaviors as compared with other rock specimens.