Effects of Redispersible Polymer Powder on Mechanical and Durability Properties of Preplaced Aggregate Concrete with Recycled Railway Ballast

The rapid-hardening method employing the injection of calcium sulfoaluminate (CSA) cement mortar into voids between preplaced ballast aggregates has recently emerged as a promising approach for the renovation of existing ballasted railway tracks to concrete tracks. This method typically involves the use of a redispersible polymer powder to enhance the durability of the resulting recycled aggregate concrete. However, the effects of the amount of polymer on the mechanical and durability properties of recycled ballast aggregate concrete were not clearly understood. In addition, the effects of the cleanness condition of ballast aggregates were never examined. This study aimed at investigating these two aspects through compression and flexure tests, shrinkage tests, freezing-thawing resistance tests, and optical microscopy. The results revealed that an increase in the amount of polymer generally decreased the compressive strength at the curing age of 28 days. However, the use of a higher polymer ratio enhanced the modulus of rupture, freezing-thawing resistance, and shrinkage resistance, likely because it improved the microstructure of the interfacial transition zones between recycled ballast aggregates and injected mortar. In addition, a higher cleanness level of ballast aggregates generally improved the mechanical and durability qualities of concrete

Preparation of Indigenous Copper Oxide Nanoparticles for Desulfurization of Natural Gas

Nanotechnology has attained significant concern in the field of Environmental Protection, Health Risk Energy, Material Science, Biotechnology, Information Technology, Pharmaceuticals, Tissue Engineering, Cosmetics, Food and Agriculture, and others. In this research the preparation of indigenous copper oxide Nanoparticles (Cu2O NPs) were prepared by the bottom up approach in the presence of Sodium do Decyl Sulfate (SDS). Material properties of Copper oxide NPs such as Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD) and Fourier Transforms Infrared (FTIR) spectroscopy were also studied. The SEM demonstrated the surface of indigenous Copper Oxide NPs was non-agglomerated powders with irregular ball resembling particles. The X-ray Diffraction (XRD) analysis explained that the Cu2O NPs were highly crystalline in nature with average size was found to be 3.5 nm ranging from 2 to 5 nm were recorded by the help of scherrer formula. The Fourier transforms infrared (FTIR) spectroscopy described the carbonyl group are responsible for formation of stable indigenous Cu2O NPs. These stable Indigenous cuprous oxide nanoparticles would be applied for the desulfurization of natural Gas separation purpose. Keywords: Indigenous, Copper oxide nanoparticles (Cu2O NPs), chemical reduction, SDS, morphology, desulfurization and natural gas. DOI: 10.7176/CPER/61-04 Publication date: April 30th 201