A Review of Recent Improvements, Developments, Effects, and Challenges on Using Phase-Change Materials in Concrete for Thermal Energy Storage and Release

Most concrete employs organic phase change materials (PCMs), although there are different types available for more specialised use. Organic PCMs are the material of choice for concrete due to their greater heat of fusion and lower cost in comparison to other PCMs. Phase transition materials are an example of latent heat storage materials (LHSMs) that may store or release thermal energy at certain temperatures. A phase transition occurs when a solid material changes from a solid state to a liquid state and back again when heat is added or removed. It is common knowledge that adding anything to concrete, including PCMs, will affect its performance. The goal of this review is to detail the ways in which PCMs affect certain concrete features. This overview also looks into the current challenges connected with employing PCMs in concrete. The review demonstrates a number of important findings along with the possible benefits that may pave the way for more research and broader applications of PCMs in construction. More importantly, it has been elucidated that the optimum PCM integrated percentage of 40% has doubled the quantity of thermal energy stored and released in concrete. Compared to conventional concrete, the macro-encapsulated PCMs showed thermal dependability, chemical compatibility, and thermal stability due to delaying temperature peaks. Furthermore, the maximum indoor temperature decreases by 1.85 °C and 3.76 °C in the test room due to the addition of 15% and 30% PCM composite, respectively. Last but not least, incorporating microencapsulated PCM has shown a positive effect on preventing freeze-thaw damage to concrete roads

Recent Advances on The Applications of Phase Change Materials in Cold Thermal Energy Storage: A Critical Review

Cold thermal energy storage (CTES) based on phase change materials (PCMs) has shown great promise in numerous energy-related applications. Due to its high energy storage density, CTES is able to balance the existing energy supply and demand imbalance. Given the rapidly growing demand for cold energy, the storage of hot and cold energy is emerging as a particularly attractive option. The main purpose of this study is to provide a comprehensive overview of the current research progress on the utilisation of PCMs in CTES. The greatest difficulties associated with using PCMs for CTES are also examined in this overview. In this regard, a critical evaluation of experimental and numerical studies of the heat transfer properties of various fundamental fluids using PCMs is conducted. Specifically, several aspects that affect the thermal conductivity of PCMs are investigated. These factors include nanoparticle-rich PCM, a form of encapsulated PCM, solids volume percentage, and particle size. Discussions focus on observations and conclusions are drawn from conducted studies on PCMs used in CTES. Based on the findings of this study, a set of plausible recommendations are made for future research initiatives

Plastic analysis of HSC beams in flexure

Abstract This article presents an experimental study on the plastic behaviour of HSC beams in bending. Nineteen isostatic beams were tested up to failure. The loading consisted of two symmetrical concentrated forces applied approximately at thirds of the span of the beams. The main purpose of the analysis is to characterize the plastic rotation capacity in the beams’ failure section with an experimental parameter. Bearing this in mind, a global plastic analysis of the tested beams is presented. The main variables of this study are the longitudinal tensile reinforcement ratio and the compressive strength of the concrete. The results obtained here are completed with others presented before and the whole set of results is analysed and discussed. The plastic rotation capacity of the tested beams are analysed with the rules of some codes of practice. Finally, a summary of the main conclusions is presented