Using waste rubber tires for concrete production will reduce the demand for natural aggregate and help to reduce environmental pollution. The main challenge of using waste rubber tires in concrete is the deterioration of mechanical properties, due to poor bonding between rubber and cement matrix. This research aims to evaluate the mechanical and thermal properties of rubberised concrete produced by using different proportions of rubber powder and silica fume. Ordinary Portland cement was partially replaced with silica fume by amounts of 5%, 10%, 15% and 20%, while sand was replaced by 10%, 20% and 30% with waste rubber powder. Tests were carried out in order to determine workability, density, compressive strength, splitting tensile strength, elastic modulus, thermal properties, water absorption and shrinkage of rubberised concrete. The compressive strength and splitting tensile strength of concrete produced using waste rubber powder were reduced by 10-52% and 9-57%, respectively. However, the reduction in modulus of elasticity was 2-36%, less severe than compressive and splitting tensile strengths. An optimum silica fume content of 15% was observed based on the results of mechanical properties. The average shrinkage of concrete containing 15% silica fume increased from -0.051% to -0.085% at 28 days, as the content of waste rubber powder increased from 10% to 30%. While the thermal conductivity of rubberised concrete was reduced by 9-35% compared to the control sample. Linear equations were found to correlate the density, splitting tensile strength, modulus of elasticity and thermal conductivity of concrete with silica fume and waste rubber powder.
This paper comprehensively examines passive and active energy retrofit strategies as a highly effective approach for reducing building energy consumption and mitigating CO2 emissions while enhancing comfort and sustainability. The paper further examines energy simulation software and assesses the integration of renewable energy systems in building to improve energy efficiency. The review used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology, ensuring a rigorous and comprehensive analysis. In addition, the study utilized bibliometric analysis with VOSviewer to provide valuable insights into the research trends and influential publications in building energy retrofits. Bibliometric analysis reveals strong collaboration among 17 authors, emphasizing their significant contributions. Keywords like energy retrofitting and efficiency are prominent, indicating their importance in academic literature. Findings show passive strategies are more effective in reducing energy consumption, though a combined approach with active strategies can yield optimal results. Retrofitting presents challenges, such as substantial initial costs and regulatory barriers. User acceptance is crucial, considering potential disruptions. The review highlights the importance of energy simulation software, with tools like EnergyPlus, eQUEST, and IES VE identified for evaluating and identifying cost-effective retrofit measures in building performance. By providing comprehensive insights into the various strategies and tools available for retrofitting buildings to achieve energy efficiency and sustainability goals, this review serves as an authoritative resource for building owners, managers, and professionals in the building industry. It offers invaluable guidance for informed decision-making and facilitates implementing effective, energy-efficient, and sustainable building retrofitting practices.