1,721,007 research outputs found
L’innovazione tecnologica dei materiali al servizio del progetto: focus sull'Architettura italiana del secondo Novecento
No full textTHE ALKALI-ACTIVATION OF CONSTRUCTION AND DEMOLITION WASTE COMPONENTS FOR STABILIZATION PURPOSES
No full textThis study investigates the potential of the different components of CDW (recycled concrete RC, recycled asphalt RA, crushed bricks and tiles BT, natural aggregate NA, and undivided CDW UND) to undergo alkali activation (AA) when mixed with an appropriate alkaline solution (AS). The feasibility of the AA of CDW fines for the stabilization of CDW aggregates was evaluated for particles smaller than 0,125 mm. A preliminary chemical characterization was carried out on different components of CDW aggregates to identify the main crystalline phases and ascertain the presence of aluminosilicates needed for the AA process. Particles of each component were afterwards mixed with three concentrations of the same AS, cast in prismatic moulds, and cured at room temperature without any thermal treatment. Mechanical tests after 3, 7, and 28 days of curing demonstrated that CDW fine powders tend to react positively in a basic environment, showing an increase in strength without any thermal treatment. These results can be translated into practical applications in the form of a methodology for improving pavement layers made up of CDW aggregates without the addition of any cementitious binders
A preliminary investigation into the use of alkali-activated blast furnace slag mortars for high-performance pervious concrete pavements
No full textPervious concrete (PC) pavements are water control systems for infiltrating storm water, reducing runoffs, contrasting heat-island effects and noise diffusion in urban environments. Their poor strength and stiffness, which stem from their porosity, limit their application for use in sidewalks and residential streets. To overcome this limitation, the research aimed at developing an alkali-activated blast furnace slag binder (AA-BFS) which, when added to the concrete mixture, would enable it to attain the characteristics required for application in trafficked road pavements. A Portland cement (CEM-I) and a blast furnace cement (CEM-III/C) were included for comparison purposes. Standard and high-performance pervious concrete (HPPC) mortars were tested with the same mix ratio of binder, sand, and admixtures. The effects of a latex polymer admixture were also analysed. After 2, 7, and 28 days of curing, AA-BFS mortars exhibited the greatest flexural and compressive strengths. As expected, CEM-III/C needed more time to achieve strengths comparable to those recorded for CEM-I. The addition of latex failed to result in any discernible benefits in terms of the stress-strain behaviour of mortars. The results confirm that AA-BFS is a sustainable option for HPPC production
Fabrication of dense and porous biphasic calcium phosphates: Effect of dispersion on sinterability and microstructural development
No full textAdvances in the field of Nanostructured Ceramic Composites
Full text linkIn recent years, the production of ceramic composites having nanosized features is receiving increasing attention, as they demonstrated enhanced mechanical and/or functional performances as respect to conventional micronic materials [...
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
A comprehensive review of direct aqueous mineral carbonation of industrial wastes using principal component analysis
Full text linkAqueous mineral carbonation has been identified as a potential solution for permanent sequestration of CO2, thus offering a sustainable approach to mitigate global warming. The present study examines recent advancements in aqueous carbonation processes, emphasizing the utilization of industrial by-products, in particular steel slags and wastes from construction sector, as reactive feedstocks. The fundamental mechanisms of carbonation in aqueous systems are analyzed, highlighting the role of solution chemistry, reaction kinetics, and mineral solubility in optimizing CO2 uptake. The high alkalinity of selected industrial by-products has been demonstrated to facilitate efficient carbonation under controlled conditions. The most common CO2 quantification techniques and carbonation efficiency equations are briefly summarized and discussed. The effects of the most significant operational parameters on enhancing the reaction efficiency are also discussed. Finally, multivariate Principal Component analysis has been adopted for the evaluation of these parameters while considering the nature of the materials and the reactor types
- …
