Schmidt J.W.,Technical University of Denmark |
Schmidt J.W.,Cowi A/S |
Hansen S.G.,Cowi A/S |
Barbosa R.A.,Technical University of Denmark |
Henriksen A.,The Danish Road Directorate
Engineering Structures | Year: 2014
A large number of concrete bridges in Denmark have to undergo wide-ranging maintenance work to prevent deterioration due to aggressive Alkali Silica Reaction (ASR). This destructive mechanism results in extensive cracking which is believed to affect the load carrying capacity of the structure. However, sufficient knowledge concerning how it influences the structures load carrying capacity and stiffness is still lacking. In particular, more knowledge concerning the shear capacity of concrete slabs without reinforcement is needed. Often ASR deterioration result in demolition of the affected concrete bridges with considerable economical expenses as a consequence. A novel ASR test and measurement method, which can be used to perform shear testing locally on concrete bridges, is presented in this paper. Shear capacity testing is performed on a three span concrete bridge and several material test samples were taken from the test areas on the bridge deck. In addition, the test method is used to directly predict the shear capacity without disturbing the traffic significantly. Verification of the load carrying capacity of the bridge was the ultimate goal of the tests. A test rig, which could easily be moved between the slab test specimens, was constructed and the test areas were made in a way which enabled simple repair of the damaged areas after testing. In general, the novel test method worked very well since it provided an on site test method, which efficiently provides an evaluation of the load carrying capacity of the tested bridge. In addition, testing and monitoring provided important information concerning the shear behaviour of ASR deteriorated concrete. The results provided sufficient information to conclude that demolition of the bridge was not necessary and consequently significant savings related to the rehabilitation costs were obtained. © 2014 Elsevier Ltd.
Mollerup M.,The Danish Road Directorate |
Hansen S.,Copenhagen University
Journal of Hydrology | Year: 2012
Recently it has been shown that the Philip power series solution can also be applied for falling head ponded infiltration (Mollerup and Hansen, 2007) or more generally for variable head (VH) ponded infiltration on flat surfaces (Mollerup, 2007). In this study, it is shown that the power series solution can also be applied for VH ponded infiltration on sloping surfaces. Numerical simulations have been made for a Guelph Loam. For a VH scenario, the power series solution was compared with a 2D FEM-solution of Richards' equation with good agreement. Using the developed series solutions, a VH scenario was compared with constant head (CH) simulations with both a ponding depth of zero and the average ponding depth as used in the VH simulations. Especially the latter gave small differences in the cumulative infiltration compared with the VH results. Simulations showed that cumulative infiltration normal to the slope as function of time is decreasing with increasing slope angles for similar vertical ponding depths, corresponding to equal amount of surface water on a given horizontal slope section. In contrast, the infiltration on a given projected horizontal area increases with the slope angle. © 2012 Elsevier B.V.
Randleff L.R.,Hermes Traffic Intelligence |
Wanscher J.B.,Hermes Traffic Intelligence |
Holm J.,The Danish Road Directorate
19th Intelligent Transport Systems World Congress, ITS 2012 | Year: 2012
The Danish Road Directorate (DRD) has been gathering floating vehicle data (FVD) for several years1,2. The data is subsequently used to estimate travel times throughout the Danish road infrastructure. This has been used for both strategic decision making as well as for tactical planning support for the commuters through Internet route planning services and numerous other applications. Even though the floating vehicle data is processed in several phases to achieve very high precision the validity of the aggregated travel times is difficult to estimate. This paper describes an advanced tool developed for using regular floating vehicle data to visually depict and by standard statistic measures evaluate the aggregated results. Considerations related to developing the application and the extended processing of floating vehicle data for validation are described, along with the results of using the tool on real data provided by DRD.
Jantzen C.,Bispebjerg Hospital |
Jorgensen H.L.,Bispebjerg Hospital |
Thomsen M.T.,Bispebjerg Hospital |
Riis T.,Bispebjerg Hospital |
And 3 more authors.
Danish Medical Journal | Year: 2014
INTRODUCTION: Different factors related to winter are known to influence the fracture incidence, but little is known about the effect of road surface temperature. This study examines the association between road surface temperature and the daily number of fractures in an urban area during two winters. MATERIAL AND METHODS: Retrospective data collection was conducted on all patients treated at Bispebjerg Hospital, Denmark, for a humeral, ankle, distal radius or hip fracture during the periods October to April 2009/2010 and 2010/2011. Patients were grouped according to age into the following categories: < 15, 15-30, 30-45, 45-60 and > 60 years. Data on road surface temperature (Tp.) were obtained from The Danish Road Directorate and grouped into the following categories: Days with Tp. > 0 °C, Tp. < 0 °C, Tp. > -5 °C, Tp. < -5 °C and ice alert (IA). RESULTS: A total of 4,892 patients (4,938 fractures) were treated during the study periods. The daily number of distal radius, humeral and ankle fractures increased significantly with decreasing road surface temperature and the presence of IA. For hip fractures no significant association was found. Decreasing temperature was associated with a significant decrease in the daily number of fractures for patients < 15 years, whereas patients > 30 years experienced a significant increase. CONCLUSION: Decreasing road temperature results in increased numbers of all fractures except hip fractures. Low temperatures is a risk factor for patients > 30 years and a protective factor for patients < 15 years.
Haustein S.,Technical University of Denmark |
Nielsen T.A.S.,The Danish Road Directorate
Journal of Transport Geography | Year: 2016
More targeted European policies promoting green travel patterns require better knowledge on differing mobility cultures across European regions. As a basis for this, we clustered the EU population into eight mobility styles based on Eurobarometer data. The mobility styles - including, for example, "green cyclists" and "convenience drivers" - differed not only in their travel-related variables but also in their socio-economic background, IT-affinity, and life satisfaction, with green cyclist showing the highest life satisfaction and two car-oriented styles having the highest socio-economic resources. In a second step, the 28 EU member countries were clustered into six country clusters based on their representation of mobility styles. The country clusters indicate the existence of considerably different mobility cultures across the EU. Sub-regions can be identified that have highly different positions on the path towards sustainable mobility and therefore different requirements towards European platforms and support measures, e.g. for 'Sustainable Urban Mobility Plans'. The country clusters can provide a starting point for future communication and targeting of European efforts in sustainable mobility. © 2016 Elsevier B.V.