Time filter

Source Type

United Kingdom

Pilakoutas K.,University of Sheffield | Neocleous K.,University of Sheffield | Angelakopoulos H.,University of Sheffield | Koutselas K.,Aggregate Industries
Concrete (London) | Year: 2010

A European research project EU FP7 Specific Targeted Research Project (STREP) EcoLanes has been undertaken to develop pavements using concrete reinforced with recycled steel tyre-cord fibers (RSTCF). Using RSTCF and industrially produced steel fibers, EcoLanes developed concretes suitable for wet consistency and RCC. Following extensive numerical and analytical work, a design framework and software were developed by UTI for use by design engineers. Analysis and design tools were developed based on the concept of long-life rigid pavements (LLRPs) made with wet/dry SFRC. Methodologies were developed for the LCA (life-cycle analysis) of LLRPs made with wet and dry SFRC. The construction of the demonstration pavements confirmed that the developed technology can be easily applied in practice. Source

Simm J.,HR Wallingford | Phillips P.,Aggregate Industries | Johansen M.,Sterna Shipping | Hahn U.,MIRO German Aggregates Federation
Coasts, Marine Structures and Breakwaters 2013: From Sea to Shore - Meeting the Challenges of the Sea | Year: 2014

Considerable effort over the last 20 years has been put into the production of harmonised European Standards. Second generation standards are now starting to emerge and plans are in place for the future development of a third generation. However, in some countries knowledge of these standards and their status remains inadequate and hence their application is inconsistent and patchy, with significant engineering and legal implications. This paper firstly describes the process of standard development illustrating it with reference to the development and use of the Armourstone standard EN13383. Possible reasons for the lack of appropriate implementation of the standards are identified and the dangers of users failing to understand the changed status of standards at European law are explained. The paper concludes with suggestions for improving future practice. Source

Villani M.,Technical University of Delft | Artamendi I.,Aggregate Industries | Kane M.,Laboratoire Central des Ponts et Chaussees | Scarpas A.,Technical University of Delft
Transportation Research Record | Year: 2011

This research examines the hysteresis friction of a sliding elastomer on various types of stone surfaces. The hysteresis friction is calculated with an analytical model that considers the energy spent by the local deformation of the rubber due to surface asperities of the stone surface. By establishing the fractal character of the stone surfaces, one can account for the contribution to rubber friction of stone roughness at different length scales. A high-resolution surface profilometer is used to calculate the three main surface descriptors and the minimal length scale that can contribute to hysteresis friction. The rubber is treated as a Zener viscoelastic material model. Modeling of the contact between the elastomer and the stone surface is based on the analytical model of Klüppel and Heinrich, which is a generalization of the Greenwood and Williamson theory of contact between spheres that are statistically distributed about a mean plane. The results show that this method can be used in order to characterize in an elegant manner the surface morphology of various stone surfaces and to quantify the friction coefficient of sliding rubber as a function of surface roughness, load, and speed. Source

Villani M.M.,Technical University of Delft | Scarpas A.,Technical University of Delft | de Bondt A.,Ooms Civiel bv | Khedoe R.,Ooms Civiel bv | Artamendi I.,Aggregate Industries
Wear | Year: 2014

Skid-resistance is one of the most important pavement surface properties with respect to driver safety. For example, the friction of asphalt concrete mixtures continuously evolves because the aggregates are subjected to polishing by rubber tires.Currently available tests for mix design optimization are focused primarily on evaluating the polishing characteristics of aggregate surfaces rather than actual AC mixtures. Factors such as aggregate gradation cannot directly be taken into account in aggregate polishing tests, and hence its effects on the friction of the overall mix are not accounted for when mixes are being designed.Using the Skid Resistance Interface Testing Device (SR-ITD®), developed for laboratory use during the European project SKIDSAFE, the evolving frictional properties of asphalt concrete mixes containing any desired combination of aggregate type, maximum size and gradation can be evaluated. The effects of the number of wheel passes and combinations of contact pressure and speed are documented.During SR-ITD testing, evolution of the surface morphology is recorded using a laser profilometer. Post-processing of the results by means of fractal analysis enables the characterization of the surface texture on the basis of three unique descriptors.By combining the variation of surface descriptors with the friction coefficient, the influence of aggregate type and gradation on the frictional response of asphalt concrete mixes can usefully be determined. © 2014 Elsevier B.V. Source

News Article | April 26, 2016
Site: http://www.greenbiz.com/

A U.K. initiative from Sainsbury’s, United Utilities and Aggregate Industries could make the local power grid smarter and prepare it for more renewable power.

Discover hidden collaborations