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Re-Use of Granite by-products for road construction
No full textIn Sardinia abundant granite by-products stockpiles deriving from the processing of ornamental granite quarries is becoming an environmental and economic issue. According to the last survey each year hundreds of thousands of cubic meters of granite by-products are currently discharged. This paper reports about an on going research focused on the evaluation of possible recycle techniques of such materials for road construction purposes using locally available resources. The main goal is to limit the exploitation of natural aggregates normally used in road construction industry, thus contributing to reduction of both energy and environmental loss.
Potential applications of granite by-products in road layers were verified from a physical and mechanical point of view. In particular, South African technical procedures for the realization of ultra compacted base layers known as G1 were studied and reproduced with the benefit of reducing the thickness of the surfacing layers. Preliminary results have shown that granite aggregates are non plastic and with good wearing resistant thus can be safely used for road base and sub-base layers. Still more studies are need in order to reach South African specificatio
Applications Of Super Compaction Tecnique Using Granite By-products
No full textSardinia is characterized by the production of a large quantity of granite by products. The extraction of granite for ornamental purposes is an important economical resource, but also determines temporary alterations of the landscape and more often permanent waste deposits producing environmental impacts. This paper reports about an ongoing research aimed to re-use granite by products efficiently and in eco-friendly manner to construct unbound pavement layers for rural roads construction durable pavements with re-using disposed materials. The potential application of using granite by-products according to the South African G1 protocol was studied aiming at reducing the environmental impact by reusing granite by products and the thickness of the surfacing bituminous layers. The results reported in this have shown the benefits of constructing unbound granular layer with granite by products for rural road pavements in the terms of mechanical strength, road durability, and economical and environmental impacts
Use Of Virgin Rocks Debris To Construct Road Pavement Super Compacted Layers
No full textSardinia has a major mining history that holds considerable importance in Italian mining economy. Sardinian mining companies that up to 2005 resulted active and registered in the trade register of the Chamber of Commerce are 241, of which 95.9% are in the branch of the extraction of non-metallic minerals, including construction material sand stones for ornamental use. Industrial minerals extracted in Sardinia represent 50% of the Italian production.
In this context the use of natural aggregates such as basalt, trachyte and andesite has been investigated in order to sustain and make the most of local natural available resources in the field of road construction.
This research has focused the attention on the evaluation of using these available granular materials for the construction of super compacted base layers according to the South-African technique of the Inverted Pavement. Inverted Pavement is a widely used method of road construction that allows a considerable saving in terms of thickness of Hot Mix Asphalt layers, as well as overall cost of the infrastructure. In this paper chemical and physical-mechanical properties of the materials in question were analyzed and the results were compared with those of the South African rocks. The results of the study made it possible to identify the design criteria to enhance the commitment of these natural resources through the maximization of their mechanical performanc
Granites by-products in comparison with the dolerite for the construction of pavement structures with the method of inverted pavement
No full textSardinia is characterized by high amounts of granite, with mining rocks for ornamental use ranked 2nd in the world after China. Direct result of mining is the production of scraps and blocks of poor ornamental quality being landfilled. The study reported on this paper is a part of an ongoing researched aimed to optimize the use of extracted rockdebris, with scope of reducing the amount of dumped material and support the sustainability of natural resources. In particular, the study focused on the use of this resource for the realization of road pavement layers according to the South-African technique of the so called “Inverted Pavement”. This technique provides high mechanical strength for an unbound base layer super compacted. The material commonly used in South Africa is the crushed stone derived from dolerite, which is present in high quantities.The possibility of using granite has being investigated according to the South Africa Technical Specifications. Granites deriving from quarries were analyzed and compared with Dolorite from the physico-chemical and mechanical point of view. According to the preliminary results obtained granites by products are a valuable resource to be used to constructed super compacted layers of Inverted Pavement
Granite By-Products for inverted pavement technique
Get PDFAs mentioned by Sardinia Region: ''Sustainable Development is what satisfies present's needs
without shattering those of future generations, thanks to smart use of environmental resources
and without waists''. This research aims to use a current resource available in high quantities
in Sardinia to optimize the uses of the extracted materials and not to take just advantage of the
Region. The mining activity in Sardinia, which is very important since ‘60s, during these
years, has produced huge amounts of granite by-products. The ornamental use of granite is an
important money source for Sardinia. Unfortunately, as the virgin material extracted must
have high aesthetic qualities, many rock blocks are rejected. This research has the aim of
making the most of the material stored in a quarry sites and of optimizing the uses of resource
stone examined.
The target is the use of granite by-products as material with high mechanical featured to be
used for road pavements, from the foundation to surface. This research gives you the
opportunity to make the most of regional resources, to minimize the thickness of asphalt,
reducing the maintenance and realization costs. This is a good start for the Island to make
money of something easy to export.
Granite by-products will be used for the construction of innovative road pavement design.
The Inverted Pavement Technique, studied and developed in South Africa since 1950, is
going to be used for road infrastructure. In particular, I have focused the attention on the
behavior of granular base layer. Thanks to this technique is actually possible to take
advantage of mechanical features of base layer, creating base layers that assure high and long
lasting performances with almost zero environmental costs. The Project is finalized to a
sustainable design by using resources, considered as waste so far, present in the Sardinian
Land and the minimal use of exhaustible and expensive row materials as asphalt layers.
The increasing costs of petrol products and their limited availability leaded to find alternative
solutions to flexible infrastructure everywhere in the world.
Another target was to make sure that European and South African Regulation matched
regarding granular aggregates. Through laboratory testing physical, chemical, and mechanical
features of granite by-products were analyzed comparing to Dolerite, used in South Africa in
the Inverted Pavement Technique
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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