Fines characterization through the methylene blue and sand equivalent test: comparison with other experimental techniques and application of criteria to the aggregate quality assessment

In road construction the general term fines is used to describe particles passing the 0.063, 0.074 or 0.08 mm sieve. Some types of fines are considered to be relatively inert and have almost no effect on pavement performance, whilst the presence of even small amounts of others can significantly affect the stiffness and freezing–thawing behaviour of unbound and hydraulically bound layers. This paper presents the results of research on 12 Slovenian aggregates produced from limestone and dolomite bedrock, and naturally occurring river alluvium gravel. At each production site three different materials were sampled and tested: the actual aggregate for unbound base layers, the clayey soils, which presented the most potentially harmful component at the specific location, and the stony dust, which presented the finest size of crushed aggregate and is typically found as coatings on the crushed grains. Six different methods were used to identify the nature of the fines: X-ray diffractometry, carbonate content determination, methylene blue, sand equivalent, Enslin–Neff water absorption, Atterberg limits test, soil suction measurements and soil water characteristic curves. Based on the results, the relationship between the properties of the different fines was determined and included in draft Slovenian national criteria for sand equivalent and methylene blue values currently being trialed.     

Housing circumstances and quality of life among local and immigrant population in Norwegian neighbourhoods

This paper explores the relationship between the concept of quality of life (QoL) and housing circumstances among the immigrant and local population of two neighbourhoods in Norway: Storhaug in Stavanger and Grünerløkka in Oslo. Objective data regarding housing circumstances, e.g., type of residence, dimension or overcrowding, is collected through spatial analysis and desktop-research. Inhabitants of these neighbourhoods are interviewed with the help of map-based questionnaires to collect both objective data regarding these housing circumstances as well as subjective data, e.g. reason of location and personal satisfaction with housing and QoL. The objective and subjective data is analysed geographically and statistically. This study finds that the immigrant group has less favourable housing circumstances than the local population. Circumstances such as type of residence, the reason of location and satisfaction with the residence are predictors for satisfaction with QoL between both groups. Being local or immigrant, as well as the study area, Storhaug and Grünerløkka, or the type of ownership were not significant predictors of satisfaction with QoL in this specific study. These findings provide a base for understanding the importance of housing circumstances for QoL. Due to the high percentage of the immigrant population and its projection in Norway, these investigations are expected to help practitioners identify housing features and design aspects that can impact on the overall satisfaction with QoL of both host and immigrant society.

     

Spanish and European innovation diffusion: a structural hole approach in the input–output field

Input–output analysis is a powerful tool for in-depth study of the productive structure of economic space. Moreover, the sectoral network constitutes one of the possible determinants of the innovative capacity of a territory. The use of network theory in the input–output field supposes an interesting alternative that allows structural complexity, weakness and strength to be shown. Following this viewpoint, we analyse the relative position of each sector via the structural holes concept (Burt in Structural Holes, Cambridge University Press, Cambridge, 1992; Social Capital: Theory and Research. Aldine de Gruyter, New York, 2001; Am J Sociol 110:349–399, 2004) to offer an approach to knowledge generation and diffusion capacity within the economic network. The theoretical background is based on the opportunities afforded due to connexion with and proximity to sectoral structure for knowledge transmission and consequently innovation capacity. This novel proposal is applied to the analysis of European and Spanish economies in 1995.     

Stresses Analysis on a Rail Part

The EFVM （Vitoria Minas Railroad） is one of the main railways in Brazil. It transports freight trains of ore, 220 wagons each. These wagons have 2 boogies of 2 axles each and 32 metric tons on metre gauge. Elastic strains were measured on a special part of this railway due to these trains. The main load to evaluate stresses and strains was a G 16 Locomotive, a C-C kind from Vale, a Brazilian Company. The measurements were obtained by dynamic deflectometer installed on a main line of this railway, near Ipatinga, a city from Minas Gerais, one of Brazil states. This track was equipped to obtain stresses under an equal repeated static load A simulation of the stresses was made under critical strain by Ferrovia 1.0 software. It was also made an evaluation of unequal results from neighbor sleepers taking in comparison two equipped parts of this railway, one with compacted ballast and no compaction to the other. The results were strain limited, avoiding breakage or damage to the studied rails. This work analyses these measurements focusing on the improvement of track quality.     

Influence of concrete strength and length/diameter on the axial capacity of CFT columns

This paper presents an experimental analysis of the confinement effects in steel–concrete composite columns regarding two parameters: concrete compressive strength and column slenderness. Sixteen concrete-filled steel tubular columns with circular cross section were tested under axial loading. The tested columns were filled by concrete with compressive strengths of 30, 60, 80, and 100 MPa, and had length/diameter ratios of 3, 5, 7, and 10. The experimental values of the columns’ ultimate load were compared to the predictions of 4 code provisions: the Brazilian Code NBR 8800:2008, Eurocode 4 (EN 1994-1-1:2004), AINSI/AISC 360:2005, and CAN/CSA S16-01:2001. According to the results, the load capacity of the composite columns increased with increasing concrete strength and decreased with increasing length/diameter ratio. In general, the code provisions were highly accurate in the prediction of column capacity. Among them, the Brazilian Code was the most conservative, while Eurocode 4 presented the values closest to the experimental results.     

Effect of a commercial dispersion of multi walled carbon nanotubes on the hydration of an oil well cementing paste

This work studies the influence of a commercial dispersion of multi wall carbon nanotubes (MWCNT) on the hydration of a class G cement paste, at room and elevated down-hole temperatures. The MWCNT dispersion was produced with a solids concentration of 3.0 % by mass and an anionic surfactant as dispersing agent. Cement pastes with water-to-cement ratio of 0.45 and additions of solid MWCNT by mass of cement up to 0.50 % were studied. Isothermal calorimetry results showed a clear retardation of the hydration of cement caused by the surfactant contained in the MWCNT dispersion. Nevertheless, thermogravimetric evaluations showed that once the hydration reaction resumed, the retardation effect of the surfactant did not have a negative impact on the amount of hydration products precipitated. It was concluded that the commercial MWCNT dispersion presents a good potential to be applied in oil well cement pastes.     

Grain size distribution analysis in polycrystalline LiF thin films by mathematical morphology techniques on AFM images and X-ray diffraction data

The influence of the deposition temperature on the grain size of polycrystalline lithium fluoride (LiF) thin films is studied using a mathematical morphology method. On atomic force microscopy images of the LiF surface, the grain sizes and shapes are determined by applying the watershed technique, together with a shape factor algorithm. Also, the domain size of the film structure, determined by an X-ray diffraction data analysis, is compared and correlated with the mean grain size as a function of the deposition temperature. In both cases a linear increase with temperature and a very good agreement among the two structural parameters (grain and domain size) was found.