To reduce dependence on fossil fuels, many thermal power plants have adopted biomass co-firing by replacing approximately 3
Brown spots caused by iron oxidation are a well known weathering phenomenon affecting granitoid stones used as cladding and paving in both contemporary and historic architecture. This study investigates the causes of this staining in a Variscan granitoid widely used in Northern Portugal and in buildings across Europe. A multidisciplinary approach combining petrography, X-ray diffraction, and SEM-EDS shows that accessory amphiboles, rather than biotite alone, are the main source of iron release. To simulate the formation of these brown spots during environmental exposure, samples were subjected to technological ageing tests in a climatic chamber under realistic environmental conditions. Accelerated weathering tests were also conducted to assess whether adjacent brown spots could result from galvanic corrosion between iron oxides and fresh mineral phases. The results appear to indicate that intergranular porosity and the microstructural arrangement of ferro-magnesian minerals exert a greater influence on oxidation kinetics. No significant galvanic effect was observed. By clarifying the role of specific mineralogical triggers, this research enhances the ability to predict the service life of building stones and contributes to the optimization of selection criteria for natural stones exposed to aggressive environmental conditions.
The construction industry’s pursuit for sustainable materials has intensified the focus on valorizing waste glass. This study investigates the combined effects of incorporating colored glass (CG), as natural sand substitute and glass fibers (F) on the performance of mortar. An extensive experimental program was carried out to evaluate the mechanical performance including compressive and flexural strength, modulus of elasticity, impact resistance, water absorption, open porosity, and microstructure characterization using Scanning Electronic Microscope (SEM) of various mortar mixes. The results highlight that a 5
A series of experimental tests were carried out to investigate the structural behavior of how well short concrete-filled steel tubular (CFST) columns with different types of fiber-reinforced concrete and top-plate bracing under axial compression perform. Three types of fibers, namely micro steel fibers, glass fiber, and glass fiber powder, were utilized at a variety of volume fractions: 1.5
This study investigates the mechanical performance and non-destructive testing (NDT) characteristics of functionally graded concrete (FGC) incorporating steel slag(SS) as a partial replacement for manufactured sand (M-sand) at substitution levels of 20
