The rapid increase in energy demand has resulted in more dependence on fossil fuels, which leads to higher CO2 emissions every year. To overcome this problem, shifting from fossil fuel-based energy resources to renewable and sustainable ones is essential. One of the new research areas developed in this context is the harvesting of energy from urban infrastructures and, in particular, roads. A large amount of energy in the form of heat or kinetic energy is wasted annually on roads. Recovering these local forms of energy as electricity would improve the energy efficiency of cities. In this review paper, recent developments in the field of energy recovery from roads using solar panels, piezoelectric, thermoelectric and electromagnetic harvesters are discussed along with their efficiency, cost and field implementation. Moreover, new advancements in developing compatible energy storage systems are also discussed and summarised. Based on the review, although all of these systems have the potential of recovering at least a part of the wasted energy, only one of them (the electromagnetic converters) is capable of generating a considerable energy level. In addition, based on the evaluation of the maturity of the technologies, and their cost analyses, more studies are required in order to fill the gap between the current state of the technologies and their full operational form.
In this study, concrete specimens, having different shapes and sizes have been studied for two different strength levels cured in air and in water. Compressive strength test was performed on cubic and cylindrical samples, having various sizes. The analyses of this investigation were focused on conversion factors for compressive strengths of different samples. Conversion factors of different specimens against cross sectional area of the same specimens were also plotted and regression analyses were done. It was found that according to the results of analyses, the best fit curves, tend to have different trends at different curing conditions.
Ethylene vinyl acetate (EVA) was used in the amounts of 5, 10 and 15% of the cement content in the production of polymer cement mortars. Besides, nanosilica, in three different sizes of 35, 17 and 4 nm, were included in the mortars. The addition of nanosilica particles in polymer cement concretes and mortars affects both fresh and hardened state properties. The extremely high surface area of nanoparticles increases the water demand; hence to obtain a workable mixture it is necessary to increase the superplasticizer used. In the hardened state, the strength and impermeability properties improve due to both pozzolanic reaction and filler effect of nanosilica particles as well as polymer film formation. The flow properties in the fresh state and flexural and compressive strength properties in the hardened state were determined.
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.