Search results for "Durability."
showing 10 items of 105 documents
An experimental investigation into the permeability and filter properties of pervious concrete for deep draining trenches
2018
The reduction of pore water pressures is one of the most effective measures that can be taken to stabilise landslides or to improve the stability conditions of marginally stable water-bearing slopes. To this end, draining trenches have been used long since. When deep trenches are needed, the usual conventional construction techniques fail and recourse must be made to secant piles or to adjacent vertical panels built by means of the methods well established for diaphragm walls. However, unbonded materials cannot be used, since the excavation of a panel adjacent to previously built ones will instabilise these latter. The problem can be solved using pervious concrete rather unbonded material. …
Durability of advanced nanocomposites based on polyethylene oxide and nanodiamonds
2016
Nanodiamonds nanoparticles (NDs) are amongst the most promising materials for multifunctional nanocomposites for various applications
The effects of a saline environment on the durability of commercial photocatalytic paints
2016
The use of photocatalytic products for surface coating of buildings ensures the reduction of certain air pollutants and greater duration of color over time, due to the reduced attitude of air particulate to adhere to the treated surfaces. The world market is producing a wide range of coatings, transparent and opaque, high initial performance, but there is a lack of data on their durability. The knowledge of performance over time of these new products is at the basis of the Regulation (EU) no. 305/2011, which repealed Council Directive 89/106/EEC and introduced the seventh requirement regarding the sustainability and particularly durability of construction works. This study focuses on the as…
Long-term properties and end-of-life of polymers from renewable resources
2017
[EN] The long-term properties and end-of-life of polymers are not antagonist issues. They actually are inherently linked by the duality between durability and degradation. The control of the service-todisposal pathway at useful performance, along with low-impact disposal represents an added-value. Therefore, the routes of design, production, and discarding of bio-based polymers must be carefully strategized. In this sense, the combination of proper valorisation techniques, i.e. material, energetic and/ or biological at the most appropriate stage should be targeted. Thus, the consideration of the end-of-life of a material for a specific application, instead of the end-of-life of a material s…
Testing mechanical characteristics of chestnut stakes used in bed sills for stream restoration
2017
Using of wood elements for constructing bed sills in Mediterranean streams, where the banks are not protected by tree vegetation, needs an evaluation of biological and mechanical characteristics for evaluating both the wood durability and the effectiveness of the stream restoration project. Very few studies have dealt both with the decay of mechanical characteristics of wood elements employed for stream restoration works and with the changes over time of physical and chemical wood characters. In this paper, for a wood and stone bed sill located in a stream having no shaded banks, the changes of physical and chemical characters detected after 12, 18, 24, 30, 36, 42 and 48 months on chestnut …
Influence of the Hourly Variation of Temperature on the Estimation of Fatigue Damage and Rutting in Flexible Pavement Design
2004
The work presented in this paper offers a contribution to understand to what extent different discretization modes for describing a whole day can affect the estimation of in-service durability of a flexible pavement, in relation with concomitant traffic flow fluctuations. Calculation of the stress–strain state was carried out with an elastic multi-layer model, and performance laws were implemented for verification of the major distress mechanisms that are able to affect the prediction of a flexible pavement’s service life. Results from the prediction of the fatigue life allow one to conclude that no big mistakes are made when evaluating the total damage by describing climatic conditions via…
Effect of climate change on asphalt binder selection for road construction in Italy
2015
This work explores the influence of climate changes on the proper selection of asphalt binder for pavement construction purposes, according to the Performance Grade (PG) defined in the SUPERPAVE specifications. Based on temperature data at national level, it is possible to obtain thematic maps for the whole Italian territory, which is extremely useful for technicians and pavement engineers for selection of asphalt binder for road construction purposes. Furthermore, the statistical significant temperature trends’ knowledge enables deriving thematic maps which allows to include the effects of climate change in the asphalt binder design. It is argued that, due to climate change, the binders to…
Serviceability of segmental concrete arch-frame bridges built by cantilevering
2013
The evaluation of the safety degree in service life for a segmental prestressed concrete bridge built by the cantilever method presents different aspects related to strength, deformability, durability and to effects of time-dependent phenomena as creep and shrinkage. The case-study of a prestressed concrete frame bridge with inclined piers is presented, built by cantilevering, with precast segments. By considering the fundamental items of design and construction stages, the implications due to the arch effect in this static scheme are investigated, with respect to an equivalent bridge with a final scheme of continuous girder on vertical piers. The birth of a significant value of axial force…
Durability evaluations on the bridge over the Ruwais lagoon at Jeddah
2008
The bridge over the Ruwais Lagoon at Jeddah, Saudi Arabia, has been built in the first half of 80s within a large-scale program project concerning the "corniche", a seafront boulevard running more than 30 Km from its northern to its southern end.
Ultimate Strength and Fatigue Durability of Steel Reinforced Rubber Loading Hoses
2010
Loading hoses in an offshore loading buoy system in the North Sea were investigated with respect to extreme load resistance and fatigue durability. Both experimental work and fatigue life analyses were carried out. The FLS test is based on the principle of a service simulation test according to the American Petroleum Institute (API) 17B guidelines. The test results given in number of endured cycles from the laboratory test are scaled to the in-service conditions. Although the life estimate is based on one full scale test only, an attempt has been made to account for the inherent scatter in fatigue life. Furthermore, the results are validated by large test series with small scale test specim…