Search results for " Laboratory test"
showing 10 items of 11 documents
Consolidation of earthen building materials: a comparative study
2019
The consolidation and protection of mud bricks are a challenge in the field of conservation of archeological sites. One of the solutions is represented by the coverage of the entire excavation that assures a protection against mud dissolution. Unfortunately, this is not always feasible, both for economical and practical issues. For these reasons, alternative solutions are needed. In this work, laboratory experimentation has been carried out in order to test the efficacy of some products to slow down the dissolution process and increase the brick toughness. Three typologies of raw materials taken from different outcrops (one from the Republic of Azerbaijan and two from Calabria region, Italy…
Role of particle characteristics in the compression behaviour of gap-graded sands
2019
Abstract The compression in gap-graded mixtures of sands with combined mineralogy has been investigated in recent research, focusing on the key factors that might imply the occurrence of convergent or non-convergent paths in compression (i.e., transitional or non-transitional behaviour). From previous work, the mineralogy of a matrix composed of larger grains seems to determine the possibility of the occurrence of transitional behaviour. Hence, if there is a strong and stiff matrix made of quartz sand particles, which are either larger than or at least of similar size to the other component, then non-convergent compression paths (i.e., transitional behaviour) are likely to occur. As a furth…
Agrigento Cathedral
2015
At present Agrigento Cathedral is affected by extensive damage that seems to be mainly due to partial slumping of the foundation soil. The chapter deals with the state of damage that affects the cathedral and the investigation carried out for the mechanical characterization of the construction, the formulation of an FE model and the assessment of the safety level with respect to the service loads and with respect to exceptional loads like seismic ones. In the chapter the details of the above investigation are discussed, consideration also being given to the monitoring carried out in order to understand whether the phenomenon affecting the cathedral is ongoing. The results of the monitoring …
Experimental investigations of the soil–concrete interface: physical mechanisms, cyclic mobilization, and behaviour at different temperatures
2016
Behaviour of the pile–soil interface is important to correctly predict the response of floating piles in terms of displacement and lateral friction. Regarding energy piles, which couple the structural roles of deep foundations with the principle of shallow geothermal energy, the response of pile–soil interfaces is influenced by seasonal and daily cyclic thermal variations. Accordingly, the goal of this paper is to experimentally investigate the response of the pile–soil interface at different temperatures. This experimental campaign aims to analyse (i) the cyclic mobilization of the shear strength of the soil–pile interface that is induced by thermal deformation of the pile and (ii) the di…
From Laboratory Mixes to Full Scale Test: Rutting Evaluation of Bio-recycled Asphalt Mixes
2021
The present paper describes the rutting behavior of innovative mixes incorporating 50% of Reclaimed Asphalt (RA) with bio-materials. They were assessed in the laboratory and in a full-scale accelerated experiment. The innovative mixes studied here contained bio-materials especially designed to help recycling by re-activating the aged binder from RA. Four mixes were evaluated: three of them are manufactured with bio-materials, (two bio-rejuvenators and one bio-binder) and one was a control mix, which was a high modulus asphalt mix (EME2). In this study, the rutting resistance of the four mixes was first evaluated in the laboratory with both European and US methods. The full-scale test was th…
Design Procedures for Soil-Lime Stabilization for Road and Railway Embankments. Part 2-Experimental Validation
2012
AbstractAs detailed in Part 1, the most common Italian Technical Specifications refer to different design methodologies for design of lime-soil mixtures, some being quite different from those internationally adopted. Therefore, it seemed appropriate to the Authors to compare these methodologies, via a wide experimental program.It is shown that the Italian methodology of the National Road Agency is different not only from those used in Italy, but also from the main international standards. The experimental results highlight that a revision of that methodology is needed in order to bring it into line with what is prescribed by the European standard.
Circulating markers of retinal and optic nerve lipids
2013
Purpose Blood lipids are frequently used as a surrogate of lipid composition of peripheral tissues. Even if it is well accepted, such a relationship has never been clearly demonstrated for the eye. The aim of this study was to determine in human samples whether a lipidomic approach based on red blood cells could reveal associations between circulating and ocular lipid profiles. Methods Red blood cells, retinas and optic nerves were collected from 9 human donors. The lipidomic analyses on these tissues were done by both, gas chromatography and liquid chromatography coupled to an electrospray ionization source-mass spectrometer (LC-ESI-MS/MS). Results Gas chromatographic approach did not show…
Ether-lipid and docosahexaenoic acid (DHA) levels in erythrocytes of patients with glaucoma
2008
International audience; Purpose: : Neuronal tissues such as the brain and the retina are known to contain elevated amounts of phospholipids with a vinyl-ether double bond (ether-lipids or plasmalogens) as well as high concentrations of long-chain omega-3 polyunsaturated fatty acids (docosahexaenoic acid or DHA). Abnormal blood levels of ether-lipids and DHA have been associated with several neurological disorders such as Alzheimer Disease. Since many observations bring up the idea of pathogenetic similarities between Alzheimer Disease and glaucoma, the aim of our work was to check whether ether-lipid and DHA levels were modified in glaucoma patients. Methods: : Blood samples were collected …
Inappropriateness in laboratory medicine: an elephant in the room?
2017
Appropriateness of diagnostic testing can be conventionally described as prescription of the right test, using the right method, at the right time, to the right patient, with the right costs and for producing the right outcome. There is ongoing debate about the real burden of inappropriateness in laboratory diagnostics. The media coverage of this issue has also recently led to either over- or under-emphasizing the clinical, organizational and economic consequences. This is quite problematic, inasmuch as some reliable data are available in the current scientific literature, showing that inappropriateness of laboratory testing can be as high as 70%. This is especially evident for, though not …
EFFECTIVENESS OF BASALT FIBRE-REINFORCED CEMENTITIOUS SYSTEMS IN CONFINING MASONRY MEMBERS: AN EXPERIMENTAL INVESTIGATION
2020
The use of composites based on fibre-reinforced polymers (FRPs) to strengthen masonry columns has become a common practice in the last decades. FRPs, however, exhibit some shortcomings when applied to masonry substrates, due to the organic nature of their matrix. For this reason, increasing attention is paid today to composites based on fibre-reinforced cementitious matrices (FRCMs), in which the polymeric matrix is replaced with an inorganic matrix (such as cementitious mortars). Cementitious matrices guarantee higher breathability and compatibility with the substrate, less sensitivity to debonding at the interfaces, and higher resistance to fire and high temperatures. Moreover, due to the…