Optimization of thin asphalt layers, OPTHINAL. Final report

Download
Jörgen Kragh
Erik Nielsen
Erik Olesen
Luc Goubert
Stefan Vansteenkiste
Joëlle De Visscher
Robert Karlsson

ERA-NET ROAD initiated a transnational research project titled "Optimization of thin asphalt layers". Thin asphalt layers have been used extensively and with promising results for more than 15 years in several countries in Europe and abroad. They seem to be cost effective, fast to build and may have good surface properties. In recent years thin asphalt layers have been shown to imply reduced traffic noise levels, increased traffic safety (skid resistance and forward visibility during wet condition) and to be durable compared with traditional alternatives.

The DRI-BRRC-VTI Consortium was trusted with carrying out the ERA-NET ROAD project and began with a State-of-the-Art report covering, among other things, a literature study and an inventory of experience with using thin asphalt layers. The results of this phase of the project were documented in a separate project report.

The main conclusions were that the application of thin asphalt layers is certainly worthwhile, in particular as a renewable "skin" of a stable road construction having sufficient bearing capacity. The skin serves road users' need for skid resistance and other important functions. Compared with more conventional and traditional surfacing such as dense asphalt concrete 0/11 or stone mastic asphalt 0/11, thin asphalt layers in general come out somewhat better in most respects; for example concerning cost, use of nature resources, rolling resistance, and traffic noise emission. However, there are also drawbacks or problems under special traffic that need to be handled, for example TAL durability when exposed to wear from studded tyres. The availability of premium quality aggregate is a prerequisite for applying thin asphalt layers, and good quality aggregate may be difficult to procure.

The present report looks at possibilities to optimize the application of thin asphalt layers, including an analysis of the cost of applying thin asphalt layers compared with the cost of applying more conventional solutions. The study has been limited to thin asphalt layers with a maximum thickness of 30 mm.

Recommendations are given concerning the best practice in applying thin asphalt layers and suggestions are given for future research needed to fill the gaps in available knowledge.

LATEST NEWS


2018-06-13

International Conference on Electric Road Systems starts today

Electric Road Systems (ERS) is a relatively new concept with many initiatives on the way. To learn from each other and stimulate new collaborations the Swedish Research and Innovation Platform for Electric Roads arranged the first international conference...


2018-05-18

Same survey of road users’ attitudes in 50 countries

At the Road Safety on Five Continents Conference, RS5C, one entire session presented a large survey of road users' attitudes in 38 countries. Results show large differences between countries in many areas, both regarding behavior and attitudes. A new survey...


2018-05-17

Good results with alcohol interlock program according to Swedish study

An alcohol interlock program makes it possible for drink driving offenders to continue their everyday lives. In a Swedish study most of the participants were satisfied with the program and experienced improved health. They also reported drinking alcohol more...


2018-05-16

Traffic safety in the spotlight

Today the Conference Road Safety on Five Continents (RS5C) opened in Jeju Island, South Korea. More than 220 participators have come from all over the world to present findings and learn about traffic safety. Dr. Young Tae Kim, Secretary-General of the...


2018-04-17

VTI will develop simulators for ambulance staff

VTI has initiated a pilot study for paramedics with the Centre for Teaching & Research in Disaster Medicine and Traumatology and Linköping University. The aim is to give ambulance staff the opportunity to practice critical medical tasks in a moving vehicle in...


2018-04-12

Unique electrified road opens in Sweden

The world’s first electrified road recharging the batteries of cars and trucks while driving opened in Sweden. The Swedish Minister for Infrastructure, Tomas Eneroth, was at the formal inauguration of the electrified road on April 11, 2018. VTI is one of 22...