Broms C.E.,WSP Sweden AB
ACI Structural Journal | Year: 2016
A novel mechanical model for the punching failure at interior columns of flat slabs without shear reinforcement is presented. It is based on fundamental structural mechanics and the stress-strain relation of compressed concrete. The shear force is assumed to be transferred to the column by an inclined circumferential compression strut that squeezes the concrete within the column perimeter, and when the compression stress in this area approaches the yield level, an increasing part of the squeezing pressure is anchored back to the surrounding concrete. Ultimately, the compression zone outside the column is assumed to collapse due to the generation of radial tension strain. Validation against test results in the literature demonstrates that the proposed model can accurately predict the punching capacity and the concurrent ultimate slab rotation. Both concentric and eccentric punching can therefore be analyzed. Copyright © 2016, American Concrete Institute.
Faith-Ell C.,WSP Sweden AB
Journal of Environmental Assessment Policy and Management | Year: 2015
This statement aims at giving an overview of the research on impact assessment in Sweden. It takes a point of departure at the introduction of impact assessment in 1991 describing the Swedish research until today. Since the introduction of EIA in the Swedish legislation in the 1990s, a large number of PhD dissertations have been dealing with various aspects of impact assessment. An estimation based on the literature search is that about 20 PhD theses, in which the core of the research is related to EIA or SEA, have been produced since 1990. The research follows four main themes: (i) EIA and SEA as a tool for integration of environmental and sustainability aspects in planning and development, (ii) EIA and SEA as a tool for integration of ecological aspects in planning, (iii) research on the basic concepts of EIA and SEA, and (iv) the relationship with other assessment tools for sustainable development. © 2015 Imperial College Press.
Homb A.,Sintef |
Guigou-Carter C.,CSTB |
Hagberg K.,WSP Sweden AB |
Building Acoustics | Year: 2016
Wooden building systems are becoming more common. Still, there are a huge variety of floor assemblies in the market. The floor assemblies normally become the weakest part due to impact load from walking persons. So far, there are no reliable standardized calculation models available regarding prediction of impact sound in the entire frequency range. Therefore, the design is always based upon previous experiences and available measurements. For the development of prediction models, the first approach is to carry out a grouping of various available floor assemblies. From that, the aim is to trace similarities and carry out simplifications. Correlation is found between the single number L'nT,w + CI,50-2500 and the mass per unit area. It is also found that the ceiling system is useful in order to optimize the construction. The data will be further processed and used in the model development and to propose optimization of wooden floor assemblies. © The Author(s) 2016.
Filipovic M.,University of Stockholm |
Woldegiorgis A.,WSP Sweden AB |
Norstrom K.,IVL Swedish Environmental Reserach Institute Ltd |
Bibi M.,IVL Swedish Environmental Reserach Institute Ltd |
And 2 more authors.
Chemosphere | Year: 2015
Historical usage of aqueous film forming foams (AFFFs) at military airports is a potential source of perfluoroalkyl acids (PFAAs) to the nearby environment. In this study, the distribution of perfluorohexanoic acid (PFHxA), perfluorooctanoic acid (PFOA), perfluorohexane sulfonate (PFHxS) and perfluorooctane sulfonate (PFOS) in soil, groundwater, surface water, tap water well, and fish muscle was investigated at a closed down military airfield (F18) and its surroundings in Stockholm, Sweden. The presence of PFOS at AFFF training sites was inventoried.One major finding of the study is that a former airfield, abandoned since 1994, may still be a point source of PFAAs to nearby recipients. PFOS and PFOA were ubiquitous in the soil samples at former AFFF training sites with concentrations ranging from 2.18 to 8520ngg-1 dry weight and <0.12-287ngg-1 dry weight respectively. The sum of PFAAs in the groundwater and surface waters ranged from 738 to 51000ngL-1 and