Search Results (2)

Magnesium oxychloride cement-based composites (MOC) with silica sand/porcelain waste blended fillers were designed and tested. The objective of the presented research was to design and test low carbon, eco-friendly and viable alternatives to Portland cement-based materials. To make new materials environmentally acceptable and sustainable, silica sand applied in the reference composite material was partially substituted by ground porcelain waste (PW) coming from used electrical insulators. The sand substitution ratio was 5, 10, and 15 vol.%. The chemical and mineralogical composition, morphology, and particle size distribution of porcelain waste were measured. For silica sand, porcelain waste, and MgO, specific density, loose bulk density, and Blaine fineness were determined. The effect of porcelain waste on the workability of fresh composite mixtures was characterized by spread diameter. The composites were characterized by their basic structural, mechanical, hygric, and thermal properties. The phase composition and thermal stability at high temperatures of MOC/porcelain waste pastes were also analyzed. Fourier-transform infrared spectroscopy (FT-IR) analysis helped to indicate main compounds formed within the precipitation of MOC phases and their reaction with porcelain waste. The usage of porcelain waste greatly decreased the porosity of composite matrix, which resulted in high mechanical resistance and reduced and decelerated water imbibition. The 10% sand substitution with porcelain waste brought the best mechanical resistance and the lowest water absorption due to the formation of amorphous phases, water-insoluble aluminosilicates. In case of the thermal performance of the examined composites, the low thermal conductivity of porcelain waste was the contradictory parameter to porosity and the high thermal stability of the phases present in porcelain slightly decreased the thermal decomposition of composites with porcelain waste dosage. Based on the results emerged from the experimental tests it was concluded that the partial substitution of silica sand in MOC composites enabled the development of materials possessing interesting and advanced function and technical parameters. Full article

Within the thermal energy storage field, one of the main challenges of this study is the development of new enhanced heat storage materials to be used in the building sector. The purpose of this study is the development of alkali-activated cements (AACs) with mechanical properties to store high amounts of heat. These AACs incorporate wastes from industrial glass process as well as microencapsulated phase change materials (mPCMs) to improve the thermal inertia of building walls, and accordingly respective energy savings. The research presented below consists of the exhaustive characterization of different AACs formulated from some waste generated during the proper management of municipal waste used as precursor. In this case study, AACs were formulated with the waste generated during the recycling of glass cullet, namely ceramic, stone, and porcelain (CSP), which is embedding a mPCM. The addition of mPCM was used as thermal energy storage (TES) material. The mechanical properties were also evaluated in order to test the feasibility of the use of the new formulated materials as a passive TES system. The results showed that the AAC obtained from CSP (precursors) mixed with mPCMs to obtain a thermal regulator material to be implemented in building walls was reached successfully. The material developed was resistant enough to perform as insulating panels. The formulated materials had high storage capacity depending on the PCM content. The durability of the mPCM shell was studied in contact with alkaline medium (NaOH 4 M) and no degradation was confirmed. Moreover, the higher the content of mPCM, the lower the mechanical properties expected, due to the porosity increments with mPCM incorporation in the formulations. Full article