Search results for " Durability"
showing 10 items of 24 documents
Experimental evaluation of the durability of innovative cementitious coatings: photocatalytic activity and colour
2012
Today, in a world context characterized by high pollution levels and increasingly limited natural resources, even in the building sector, focusing on environmental issues, through energy saving and a more rational use of these resources, both during construction and management, is fundamental. An important contribution in this direction is given by the knowledge of the durability of products and building components, especially when innovative products are applied and no information are available on the reliability and service life. The research concerns the evaluation of the durability of cement-based photocatalytic coatings ("rasanti" in the Italian diction), containing different types of …
Durability of Basalt/Hemp Hybrid Thermoplastic Composites
2019
The Achilles heel of thermoplastic natural fibre composites is their limited durability. The environmental degradation of the mechanical properties of hemp and hemp/basalt hybrid-reinforced high-density polyethylene (HDPE) composites has been investigated with a special focus on the effects of water ageing and accelerated ageing, including hygrothermal and UV radiation. Modification of the matrix was carried out using a maleic anhydride high-density polyethylene copolymer (MAPE) as a compatibilizer. Hybridization of hemp fibres with basalt fibres and the incorporation of MAPE were found to significantly decrease the water uptake (up to 75%) and increase the retention of mechanical propertie…
Evolved factor method for service life prediction of building components
2013
Key issues in the production process associated with construction are the implementation of quality and sustainability principles. Indeed, it is increasingly important in the maintenance of quality levels provided by materials, components and building structures, especially after the recent Regulation (EU) No. 305/2011. This document introduced the seventh requirement for the sustainable use of natural resources, guaranteeing the durability of construction products, thus being planned. The international standard for the assessment of durability of building materials and components is the ISO 15686 - Buildings and constructed assets - Service life planning, providing the definition of the Re…
Experimental evaluation of plasters durability aimed at maintenance planning and scheduling
2011
The phase of building management has a strategic importance because of the necessary scheduling of maintenance during executive planning. Moreover, in order to obtain the greatest sustainability of the intervention, a reasonable duration of service life must be balanced with global quality-cost ratio. A contribution towards this objective is given by the reduction in the achievable resources and raw materials consumption through the improvement of the durability requirement of building and its parts. This is true even for the interventions on the existing public building stock, especially if there is lacking of maintenance planning and scheduling. This work, taking cues from a maintenance i…
Durability of flax-basalt hybrid composites for marine applications
2015
The aim of the present work is to evaluate the influence of external layers of mat basalt on the durability behaviour and performances of flax/epoxy laminates. To this scope, long-term aging tests were performed to evaluate the durability of the two different laminates in critical environmental conditions. In particular, Flax composites were constituted by ten layers of bidirectional flax fabric whereas hybrid laminates (i.e. Flax-Basalt) were produced by replacing four external layers of bidirectional flax with four layers of basalt mat. Both laminates had a total average thickness equal to 3 mm. The samples were exposed to critical environmental conditions following the ASTM B 117 standar…
Cornicioni e sistemi di smaltimento delle acque meteoriche nell’architettura tradizionale mediterranea. Conoscenza, durabilità e recupero compatibile…
2020
The essay explores the construction aspects of cornices that, from elements of protection, they can also become elements of degradation and instability due to their shape. We would analyze formal and material values of a cornice: it presents complex characters and summarizes problems deriving from construction requirements of building envelope, due to the double value of ornamentation (crowning of building) and functional component (removal system of meteoric water from façade). This study suggests a repertoire of “rules of art”: deriving from treatises and manuals and constituting points of reference for historical construction. We would indicate the main degradations that the shape of cor…
THE DURABILITY OF INNOVATIVE CEMENTITIOUS COATINGS: PHOTOCATALYTIC ACTIVITY AND COLOUR
2012
Today, in a world context characterized by high pollution levels and increasingly limited natural resources, even in the building sector, focusing on environmental issues, through energy saving and a more rational use of these resources, both during construction and management, is fundamental. An important contribution in this direction is given by the knowledge of the durability of products and building components, especially when innovative products are applied and no information are available on the reliability and service life. The research concerns the evaluation of the durability of cement-based photocatalytic coatings (“rasanti” in the Italian diction), containing different types of …
Effect of environmental conditions on the durability of polycarbonate for the protection of cultural heritage sites.
2019
Polycarbonate is a good material for covering and protecting cultural heritage sites because of its durability, mechanical properties, and transparency. However, polycarbonate degrades under environmental weathering with a significant decrease of physical and mechanical properties and loss of transparency. In this work, the contemporary presence of ultraviolet irradiation and different temperature and moisture conditions have been taken into account to study the environmental degradation of this polymer with regard to its mechanical and optical properties. The photo-oxidation reactions cause a decrease in the molecular weight and the formation of many oxygenated species. The hydrolytic sci…
Hydrothermal Ageing Effect on Reinforcement Efficiency of Nanofibrillated Cellulose/Biobased Poly(butylene succinate) Composites
2022
Nanofibrillated cellulose (NFC) is a sustainable functional nanomaterial known for its high strength, stiffness, and biocompatibility. It has become a key building block for the next-generation of lightweight, advanced materials for applications such as consumer products, biomedical, energy storage, coatings, construction, and automotive. Tunable and predictable durability under environmental impact is required for high performance applications. Bio-based poly (butylene succinate) (PBS) composites containing up to 50% NFC content were designed and aged in distilled water or at high relative humidity (RH98%). PBS/NFC composites are characterized by up to 10-fold increased water absorption ca…
Durability of Dolutegravir-Based Regimens: A 5-Year Prospective Observational Study
2021
This study evaluates the frequency and causes of dolutegravir (DTG) discontinuation along 5 years of follow-up, in both antiretroviral treatment (ART)-naive and experienced people living with HIV (PLWH). This is a prospective multi-center cohort study enrolling PLWH on DTG from July 2014 until November 2020. DTG-durability was investigated using the Kaplan-Meier survival curve. The Cox proportional-hazards model was used for estimating the hazard ratio (HR) of DTG discontinuation for any cause, and for adverse events (AEs). Nine hundred sixty-three PLWH were included, 25.3% were women and 28.0% were ART-naive. Discontinuations for any causes were 10.1 [95% confidence interval (95% CI) 8.9-1…