Transportation Research Record: Journal of the Transportation Research Board, 2005
Page 1. Transportation Research Record: Journal of the Transportation Research Board, CD 11-S, Tr... more Page 1. Transportation Research Record: Journal of the Transportation Research Board, CD 11-S, Transportation Research Board of the National Academies, Washington, DC, 2005, pp. 311318. 311 The first reinforced concrete ...
In the Netherlands, there is a need to determine the capacity of bridge decks as a large number o... more In the Netherlands, there is a need to determine the capacity of bridge decks as a large number of them were built back in the 60’s and 70’s. Since then, not only a lot of additional safety requirements have been incorporated into the modern codes but the traffic flow has also increased drastically. The current research deals with this question by taking into account arching action or compressive membrane action (CMA) in transversely prestressed decks on concrete girders. CMA is a phenomenon that occurs in deck slabs with edges restrained against lateral movement by stiff boundary elements. This restraint induces in-plane forces in the slab affecting both the flexural and the punching shear capacities. Existing methods were modified and a MATLAB program was developed to include the effect of CMA and the transverse prestressing to calculate the punching shear capacity of bridge decks. It was concluded that transverse prestressing enhances the CMA and improves the structural behaviour...
Most of the Dutch bridges were built around middle of the last century and it is vital for design... more Most of the Dutch bridges were built around middle of the last century and it is vital for designers to find out if these bridges can still be considered safe for the traffic of modern times. The capacity in shear is especially critical as it was not considered in design recommendations before 1976. Therefore, experiments on a 1:2 scale model of a transversely prestressed concrete bridge deck cast between concrete girders were carried out to investigate the bearing (punching shear) capacity. The scale was selected based on the space available in the laboratory and the expected failure loads that would have to be applied. Also, a three‐dimensional, solid, nonlinear finite element model was developed in the Finite Element Analysis software package TNO DIANA to study the structural behavior of deck slabs and is the focus of this paper. The results of the experimental and numerical analyses leads to the conclusion that existing bridges still have significant residual strength due to the...
This paper presents an improved and more realistic approach to evaluate the deterioration process... more This paper presents an improved and more realistic approach to evaluate the deterioration process and optimise the repair strategy of concrete structures. It is based on the commonly used probabilistic-based reliability analysis methods, but takes into account the spatial variability of concrete properties that has great impact on the design and maintenance decisions of structures. The developed approach is exemplified by the concrete bridge ‘Wilpsedijk’ in the Netherlands to show the service lifetime prediction based on spatial variability of concrete deterioration including initiation and propagation period. With respect to an established repair criterion, available repair options and the corresponding repair costs, the optimal lifetime repair strategy is determined. In comparison with most of the studies that neglect the variables with random spatial variability, the approach reflects the actual situation more realistically and can produce useful information as the proportion or percentage of the surfa...
Energy consumption and CO 2-emission of concrete can be reduced when cement is replaced by second... more Energy consumption and CO 2-emission of concrete can be reduced when cement is replaced by secondary materials such as residual products from other industries. However, for the design of such environmentally friendly concretes, predicting its performance is very important. In this article a cyclic design method is presented, which can predict the strength of a concrete mixture based on particle packing technology. In the procedure, the amount of water is estimated from the required workability and calculated packing density. After that, the strength of that mixture is predicted from packing density calculations and the amount of water in the mixture via the cement spacing factor. This cycle is repeated until the mixture composition does not have to be adjusted anymore to comply with the desired performance or strength class. With the presented cyclic design procedure cement contents can be decreased without changing concrete properties in a negative way, thereby saving up to 57 % of Portland cement and reducing CO 2-emission with 25 %. This is shown by experimental results of ecological concrete mixtures tested on compressive strength, tensile strength, modulus of elasticity, shrinkage, creep and electrical resistance. The results confirmed that relationships between cube compressive strength, tensile splitting strength and modulus of elasticity correspond to those for normal concrete. The experimental program showed the possibility to use cube compressive strength as the governing design parameter in the cyclic design procedure for ecological concrete. Furthermore, it is shown how the cyclic design method can be used for defined-performance concrete design.
Transportation Research Record: Journal of the Transportation Research Board, 2005
Page 1. Transportation Research Record: Journal of the Transportation Research Board, CD 11-S, Tr... more Page 1. Transportation Research Record: Journal of the Transportation Research Board, CD 11-S, Transportation Research Board of the National Academies, Washington, DC, 2005, pp. 311318. 311 The first reinforced concrete ...
In the Netherlands, there is a need to determine the capacity of bridge decks as a large number o... more In the Netherlands, there is a need to determine the capacity of bridge decks as a large number of them were built back in the 60’s and 70’s. Since then, not only a lot of additional safety requirements have been incorporated into the modern codes but the traffic flow has also increased drastically. The current research deals with this question by taking into account arching action or compressive membrane action (CMA) in transversely prestressed decks on concrete girders. CMA is a phenomenon that occurs in deck slabs with edges restrained against lateral movement by stiff boundary elements. This restraint induces in-plane forces in the slab affecting both the flexural and the punching shear capacities. Existing methods were modified and a MATLAB program was developed to include the effect of CMA and the transverse prestressing to calculate the punching shear capacity of bridge decks. It was concluded that transverse prestressing enhances the CMA and improves the structural behaviour...
Most of the Dutch bridges were built around middle of the last century and it is vital for design... more Most of the Dutch bridges were built around middle of the last century and it is vital for designers to find out if these bridges can still be considered safe for the traffic of modern times. The capacity in shear is especially critical as it was not considered in design recommendations before 1976. Therefore, experiments on a 1:2 scale model of a transversely prestressed concrete bridge deck cast between concrete girders were carried out to investigate the bearing (punching shear) capacity. The scale was selected based on the space available in the laboratory and the expected failure loads that would have to be applied. Also, a three‐dimensional, solid, nonlinear finite element model was developed in the Finite Element Analysis software package TNO DIANA to study the structural behavior of deck slabs and is the focus of this paper. The results of the experimental and numerical analyses leads to the conclusion that existing bridges still have significant residual strength due to the...
This paper presents an improved and more realistic approach to evaluate the deterioration process... more This paper presents an improved and more realistic approach to evaluate the deterioration process and optimise the repair strategy of concrete structures. It is based on the commonly used probabilistic-based reliability analysis methods, but takes into account the spatial variability of concrete properties that has great impact on the design and maintenance decisions of structures. The developed approach is exemplified by the concrete bridge ‘Wilpsedijk’ in the Netherlands to show the service lifetime prediction based on spatial variability of concrete deterioration including initiation and propagation period. With respect to an established repair criterion, available repair options and the corresponding repair costs, the optimal lifetime repair strategy is determined. In comparison with most of the studies that neglect the variables with random spatial variability, the approach reflects the actual situation more realistically and can produce useful information as the proportion or percentage of the surfa...
Energy consumption and CO 2-emission of concrete can be reduced when cement is replaced by second... more Energy consumption and CO 2-emission of concrete can be reduced when cement is replaced by secondary materials such as residual products from other industries. However, for the design of such environmentally friendly concretes, predicting its performance is very important. In this article a cyclic design method is presented, which can predict the strength of a concrete mixture based on particle packing technology. In the procedure, the amount of water is estimated from the required workability and calculated packing density. After that, the strength of that mixture is predicted from packing density calculations and the amount of water in the mixture via the cement spacing factor. This cycle is repeated until the mixture composition does not have to be adjusted anymore to comply with the desired performance or strength class. With the presented cyclic design procedure cement contents can be decreased without changing concrete properties in a negative way, thereby saving up to 57 % of Portland cement and reducing CO 2-emission with 25 %. This is shown by experimental results of ecological concrete mixtures tested on compressive strength, tensile strength, modulus of elasticity, shrinkage, creep and electrical resistance. The results confirmed that relationships between cube compressive strength, tensile splitting strength and modulus of elasticity correspond to those for normal concrete. The experimental program showed the possibility to use cube compressive strength as the governing design parameter in the cyclic design procedure for ecological concrete. Furthermore, it is shown how the cyclic design method can be used for defined-performance concrete design.
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Papers by Joost Walraven