Search results for "durability."

Raising the fatigue durability curves in case of the rehabilitation welding techniques

2018

Effect of antibacterial/adhesive approaches on bonding durability of fiber posts cemented with self-etch resin cement

2017

Background Longevity of post-retained restoration is highly depended on bonding stability of fiber post (FP) to root dentin. This study evaluated the effect of different antibacterial/adhesive approaches on bonding durability of FPs luted into root canal with a self-etch cement. Material and methods Seventy-two human maxillary central incisor roots were divided into six groups after endodontic treatment, based on the antibacterial/adhesive treatments as follows: 1)ED primer II (ED, control); 2) Clearfil Protect Bond (PB); 3) 2% chlorhexidine (CH) pretreatment + ED primer II (CH+ED); 4) CH-incorporated into ED primer II (CH in ED); 5) CH pretreatment + Clearfil SE Bond (CH+SE); and 6)CH-inco…

The durability of carbon fiber/epoxy composites under hydrothermal ageing

2011

Studies on fibre reinforced composites are now receiving greater attention. Industrial applications have been successful in areas like aerospace, automobile, marine, construction and sporting goods. The first generation of epoxy resins for use in carbon fibre composites are able to achieve optimized high stiffness modules and high heat resistance by a high crosslink density, reached through thermal curing. However, these formulations can be very toxic and brittle with low crack resistance, which was a major disadvantage for structural applications. In the last years the use of ionizing radiation as alternative to thermal curing has been proposed as an environmentally friendly process. Furth…

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…

The assessment over time of the performance of jute-basalt hybrid composites for cladding panels

2017

The technology of dry assembly to produce multi-layer panels is an efficient alternative to traditional systems. Eco-sustainable systems are increasingly studied, particularly fiber reinforced composites for external cladding, based on natural fibers. Nevertheless, durability data on these composites are still lacking, being this is a really actual theme, especially for their potential use in outdoor applications. In this way, hybridization of natural fibers with mineral fibers as basalt ones appears promising. In the present paper, the performance of jute-reinforced laminate was compared with those of two jute/basalt reinforced hybrid laminates. The laminates were manufactured by means of …

The durability of basalt fibres reinforced polymer (BFRP)

2014

The technology of dry assembly for the production of multi-layer panels has evolved over the past 30 years, becoming an efficient alternative to traditional systems. The direction taken by the market has been increasingly drawn to eco-sustainable systems and in this way, the interest in the use of laminated composite panels for cladding, basalt fibres based. Basalt is a natural rock, silica based, which is produced through a variety of industrial processes into filaments, wool, chopped strands and fabrics. It is characterized by high resistance in chemically aggressive environments, high fire resistance, high mechanical resistance to compression and bending. The study focuses on two types o…

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…

Fatigue Design of Roller Bearing for Large FPSO Turrets

2012

The present report presents the fatigue design and a fatigue life prediction method for large roller bearings applied in the turret turn table for large Floating Production Storage and Offloading (FPSO) units. The contact point between wheel and rail in these bearings is subjected to a multi-axial stress situation and both surface wear and fatigue cracking may occur. Stress analyses with contact elements are carried out and a methodology based on the Dang Van fatigue criterion is adopted. The criterion is based on an equivalent stress defined as a combination of the fluctuation of the shear stress from its mean value and the associated hydrostatic stress at a critical plane at any time. The…