Skidding Characteristics of Pavement Surfaces Incorporating Steel Slag Aggregates

Author(s):  
A. F. Stock ◽  
Colin M. Ibberson ◽  
I. F. Taylor

Steel slag, a by-product of the steel industry, has been used in road construction in South Yorkshire and its environs for the past 60 years. Local highway engineers have anecdotal evidence of good long-term antiskid performance from road surfacings that incorporate steel slag aggregate, and these materials have remained popular with users. In view of the move toward performance measurements for paving materials, a systematic study of the performance of paving materials incorporating slag has been set up as a combined industry-university project with the assistance of the Teaching Company Directorate. The evaluation of the skid resistance characteristics of steel slag aggregates and the skidding characteristics of pavement surfaces incorporating steel slag aggregate are reported. The research program developed a modified specimen preparation procedure that significantly reduced the scatter in polished stone value (PSV) results. The field data showed that all steel slag surfaces provided good long-term skid resistance and that the 14-mm chippings exceed the performance expectations of rock chippings with similar PSVs.

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Mohd Rosli Hainin ◽  
Nur Izzi Md. Yusoff ◽  
Mohd Fahmi Mohammad Sabri ◽  
Mohd Azizi Abdul Aziz ◽  
Mohd Anwar Sahul Hameed ◽  
...  

As natural aggregate sources are becoming depleted due to high demand in road construction and the amount of disposed waste material keeps increasing, researchers are exploring the use of alternative materials which could preserve natural sources and save the environment. In this study, steel slag was used as an aggregate replacement in conventional dense graded asphalt mixes (ACW14 and ACB28). Steel slag was selected due to its characteristics, which are almost similar to conventional aggregates, and the fact that it is easily obtainable as a by-product of the steel industry. The same gradations of mixtures were produced using normal crushed aggregate as control samples. The Marshall mix design system was used for sample preparation in accordance with Malaysian specifications. Samples of asphaltic concrete were subjected to the resilient modulus test, creep test and rutting test. Samples made from steel slag show significantly better results than conventional aggregate. Therefore, utilization of steel slag will reduce land fill, save natural resources and improve the strength of pavement to sustain a higher volume of vehicles. This will shift the gear in sustainable pavement construction, which is most desirable in today’s energy deficient world.


2020 ◽  
Vol 150 ◽  
pp. 02017
Author(s):  
Nizar Sebbar ◽  
Abdelaziz Lahmili ◽  
Lahcen Bahi ◽  
Latifa Ouadif

The road construction sector draws large quantities of materials every day to meet the needs of infrastructure networks. The main aim of the link between different regions is to facilitate the transport and connection of these agglomerations. With such a pace, a shortage of these materials is worsening by the day, causing an imbalance in our “ecosystem” on the way. All these factors and many others have raised the alarm among managers in the construction industry. Environmental organizations have since been constantly seeking palliative solutions to this global scourge. In addition, several industries generate a large amount of waste annually, in some cases recoverable while respecting certain technical and environmental criteria. It is in this environmental approach, embracing a philosophy of circular economy that multiple co-products (Slag, Fly Ash, Phosphogypsum, Silica Fume…etc.) have been tested and numerous studies have demonstrated their ability to be used as a substitute for natural resources. In this respect, the following article will focus, through studies conducted in public laboratory, on various mixtures of the "soil-slag" couple to assess their possible use in road engineering. First, an identification of the materials (soil from the Sidi Kacem region and slags from a steel industry) to be adopted in our analysis will be carried out, then we will proceed to Proctor/CBR tests on soil-slag mixtures, defined in advance in order to decide on the possibility of developing them in road engineering and thereby reduce the quantities in contribution of noble materials.


1968 ◽  
Vol 41 (4) ◽  
pp. 890-894
Author(s):  
E. M. Bevilacqua ◽  
E. P. Percarpio

Abstract In an effort to achieve uniformity in testing and reporting skid resistance as a necessary preliminary to attempts to make improvements in roads on a rational basis, cooperative efforts have been underway over the past several years to standardize apparatus and equipment. One part of this effort has been the designation of a standard tire (ASTM E249-64T) for skid resistance testing. At the time this standard was set up important factors in skid resistance were not fully known and a composition was chosen on the basis that it was representative of actual tread stocks which have been used and had skid resistance shown by experience to be satisfactory. We have recently described evidence that the skid resistance of tires on real roads can be described absolutely in terms of properties of the tread stock which can be measured readily in the laboratory. In the course of this work we have further found evidence that the proposed standard tire is not as sensitive to variation in properties of the road as others which might be used. We have also shown that important properties of the road surface can be measured without a priori knowledge of the character of the road by the use of more than one rubber composition at the same location. Finally, we have observed that speed sensitivity of friction on road surfaces can be determined by low speed measurements. This report is therefore written to suggest that consideration be given to revision of procedures currently in view to take advantage of advances in our present state of knowledge. Since the recommendations constitute a substantial departure, they are not set forth here in specific detail, but their basis presented for consideration.


2018 ◽  
Vol 2 ◽  
pp. e26340
Author(s):  
Sheldon Teare ◽  
Katrina McCormick

Preparators and taxidermists spend a great deal of time preparing osteological materials before these can enter collections. The different preparation methods can have variable results and even the type of specimen being prepared can impact on its overall finish after preparation. This can often result in a lot of extra preparation work to finish or tidy up specimens. Common methods for preparation include maceration, dermestid beetles, burial and composting. Most techniques require initial preparation (flensing) and subsequent work that often introduces more chemicals or handling of the specimens. Each method has uncontrolled elements and difficulties. Dermestids are sometimes temperamental in their preferences and require a lot of care to maintain. Maceration often involves additives like detergents or follow-up chemical treatments. Burial is often highly uncontrolled, leading to problems of drainage and the build-up of unwanted pH environments. Marine mammals or larger specimens present further challenges, being oily or too large to process onsite. When these types of specimens are buried they must often be further processed before entering the collections. All of these different processes can have an impact on the long-term preservation of the individual specimens, which is a concern for conservators. A separate project was set up to investigate how illegally traded bones (tiger in this case) are affected by various environmental (“preparation”) conditions. A series of stations was set up simulating different environments, one being a compost. This started off further investigations into composting as a viable routine preparation technique. We will contrast the recent recovery of three buried beaked whales with composting trials of a frozen unflensed beaked whale skull and a small whole dolphin. The composting techniques seem to allow greater control, and produced excellent results. Our visual results will be complemented with data from the compost site, such as temperature loggers. This is currently an ongoing investigation and it is hoped that further data will be collected over time, such as pH testing of soil samples from burial sites and compost sites. Data from two trials at the Australian Museum – a larger outdoor controlled compost heap and smaller plastic tub composts – will be presented. This project highlights the importance of data collection during specimen preparation. The pathways a specimen goes through before entering a collection have an impact on its long-term preservation and research potential. These data need to be retained.


Author(s):  
Robert Klinck ◽  
Ben Bradshaw ◽  
Ruby Sandy ◽  
Silas Nabinacaboo ◽  
Mannie Mameanskum ◽  
...  

The Naskapi Nation of Kawawachikamach is an Aboriginal community located in northern Quebec near the Labrador Border. Given the region’s rich iron deposits, the Naskapi Nation has considerable experience with major mineral development, first in the 1950s to the 1980s, and again in the past decade as companies implement plans for further extraction. This has raised concerns regarding a range of environmental and socio-economic impacts that may be caused by renewed development. These concerns have led to an interest among the Naskapi to develop a means to track community well-being over time using indicators of their own design. Exemplifying community-engaged research, this paper describes the beginning development of such a tool in fall 2012—the creation of a baseline of community well-being against which mining-induced change can be identified. Its development owes much to the remarkable and sustained contribution of many key members of the Naskapi Nation. If on-going surveying is completed based on the chosen indicators, the Nation will be better positioned to recognize shifts in its well-being and to communicate these shifts to its partners. In addition, long-term monitoring will allow the Naskapi Nation to contribute to more universal understanding of the impacts of mining for Indigenous peoples.


Author(s):  
Lindsey C Bohl

This paper examines a few of the numerous factors that may have led to increased youth turnout in 2008 Election. First, theories of voter behavior and turnout are related to courting the youth vote. Several variables that are perceived to affect youth turnout such as party polarization, perceived candidate difference, voter registration, effective campaigning and mobilization, and use of the Internet, are examined. Over the past 40 years, presidential elections have failed to engage the majority of young citizens (ages 18-29) to the point that they became inclined to participate. This trend began to reverse starting in 2000 Election and the youth turnout reached its peak in 2008. While both short and long-term factors played a significant role in recent elections, high turnout among youth voters in 2008 can be largely attributed to the Obama candidacy and campaign, which mobilized young citizens in unprecedented ways.


2016 ◽  
Vol 1 (1) ◽  
Author(s):  
Dr. Kamlesh Kumar Shukla

FIIs are companies registered outside India. In the past four years there has been more than $41 trillion worth of FII funds invested in India. This has been one of the major reasons on the bull market witnessing unprecedented growth with the BSE Sensex rising 221% in absolute terms in this span. The present downfall of the market too is influenced as these FIIs are taking out some of their invested money. Though there is a lot of value in this market and fundamentally there is a lot of upside in it. For long-term value investors, there’s little because for worry but short term traders are adversely getting affected by the role of FIIs are playing at the present. Investors should not panic and should remain invested in sectors where underlying earnings growth has little to do with financial markets or global economy.


2019 ◽  
Vol 20 (3) ◽  
pp. 251-264 ◽  
Author(s):  
Yinlu Feng ◽  
Zifei Yin ◽  
Daniel Zhang ◽  
Arun Srivastava ◽  
Chen Ling

The success of gene and cell therapy in clinic during the past two decades as well as our expanding ability to manipulate these biomaterials are leading to new therapeutic options for a wide range of inherited and acquired diseases. Combining conventional therapies with this emerging field is a promising strategy to treat those previously-thought untreatable diseases. Traditional Chinese medicine (TCM) has evolved for thousands of years in China and still plays an important role in human health. As part of the active ingredients of TCM, proteins and peptides have attracted long-term enthusiasm of researchers. More recently, they have been utilized in gene and cell therapy, resulting in promising novel strategies to treat both cancer and non-cancer diseases. This manuscript presents a critical review on this field, accompanied with perspectives on the challenges and new directions for future research in this emerging frontier.


Author(s):  
Nils Brunsson

This chapter argues that organizational reforms are driven by problems to be addressed, by solutions to be applied, and by forgetfulness. The greater the supply of any of these factors, the more likely it is that reforms will occur. Without problems, reforms are difficult to justify; without solutions they cannot be formulated; and without forgetfulness there is a risk that people will be discouraged by the fact that similar reforms have been tried and have failed in the past. In contemporary large organizations, problems tend to be easily found. Those interested in selling solutions often try to supply problems as well — problems that can be solved by their solutions. Forgetfulness can be promoted by the use of consultants with limited experience of the implementation and long-term effects of reforms. Reforms are also self-referential; they tend to cause new reforms. Thus, reforms can be considered as routines: they are likely to be repeated over and over again.


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