Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Long‐term behavior of slender long‐span precast prestressed high‐strength concrete girders
https://orcid.org/0000-0002-5644-8889
https://orcid.org/0000-0001-6413-4217
https://orcid.org/0000-0002-3254-2221
https://orcid.org/0000-0003-1690-9887
AbstractThe long‐term behavior of slender (1/40) long‐span precast high‐strength concrete girders was experimentally investigated regarding their use as a competitive solution in relation to steel alternatives for highway overpasses. The time‐dependent effects of full‐scale girders has rarely been addressed, particularly the influence of creep and shrinkage of concrete with compressive strengths around 120 MPa. Two half‐scale girder specimens were produced using an economically optimized and high‐strength concrete mixture, nonfiber reinforced, designed only with conventional raw materials, currently available at Portuguese precast companies, and subjected to long‐term loading, with a magnitude of approximately 50% of the failure load in bending, during a period of 3.75 years. Using the same mixture, prismatic specimens were also produced and subjected to long‐term loading at 24 h and 7 days of age to assess both creep and shrinkage. Results show that the age of concrete at the loading day is of paramount importance regarding the time‐dependent effects. These are most relevant during the first days of loading and tend to stabilize from the 112th day of loading onward. The time‐dependent girder's mid‐span deflection at the end of the 3.75 years did not exceed more than 50% of the initial deformation. Comparison of results with those obtained with Model Code 2010 and the current version of Eurocode 2 shows that these underestimate strains and deflections due to creep, mostly because the short‐term development of these effects, occurring during the first days of loading, are not adequately represented. On the contrary, a sound agreement between experimental and theoretical values, both in short and long term, was obtained using the Auperin et al. approach.
Long‐term behavior of slender long‐span precast prestressed high‐strength concrete girders
https://orcid.org/0000-0002-5644-8889
https://orcid.org/0000-0001-6413-4217
https://orcid.org/0000-0002-3254-2221
https://orcid.org/0000-0003-1690-9887
AbstractThe long‐term behavior of slender (1/40) long‐span precast high‐strength concrete girders was experimentally investigated regarding their use as a competitive solution in relation to steel alternatives for highway overpasses. The time‐dependent effects of full‐scale girders has rarely been addressed, particularly the influence of creep and shrinkage of concrete with compressive strengths around 120 MPa. Two half‐scale girder specimens were produced using an economically optimized and high‐strength concrete mixture, nonfiber reinforced, designed only with conventional raw materials, currently available at Portuguese precast companies, and subjected to long‐term loading, with a magnitude of approximately 50% of the failure load in bending, during a period of 3.75 years. Using the same mixture, prismatic specimens were also produced and subjected to long‐term loading at 24 h and 7 days of age to assess both creep and shrinkage. Results show that the age of concrete at the loading day is of paramount importance regarding the time‐dependent effects. These are most relevant during the first days of loading and tend to stabilize from the 112th day of loading onward. The time‐dependent girder's mid‐span deflection at the end of the 3.75 years did not exceed more than 50% of the initial deformation. Comparison of results with those obtained with Model Code 2010 and the current version of Eurocode 2 shows that these underestimate strains and deflections due to creep, mostly because the short‐term development of these effects, occurring during the first days of loading, are not adequately represented. On the contrary, a sound agreement between experimental and theoretical values, both in short and long term, was obtained using the Auperin et al. approach.
Long‐term behavior of slender long‐span precast prestressed high‐strength concrete girders
https://orcid.org/0000-0002-5644-8889
https://orcid.org/0000-0001-6413-4217
https://orcid.org/0000-0002-3254-2221
https://orcid.org/0000-0003-1690-9887
AbstractThe long‐term behavior of slender (1/40) long‐span precast high‐strength concrete girders was experimentally investigated regarding their use as a competitive solution in relation to steel alternatives for highway overpasses. The time‐dependent effects of full‐scale girders has rarely been addressed, particularly the influence of creep and shrinkage of concrete with compressive strengths around 120 MPa. Two half‐scale girder specimens were produced using an economically optimized and high‐strength concrete mixture, nonfiber reinforced, designed only with conventional raw materials, currently available at Portuguese precast companies, and subjected to long‐term loading, with a magnitude of approximately 50% of the failure load in bending, during a period of 3.75 years. Using the same mixture, prismatic specimens were also produced and subjected to long‐term loading at 24 h and 7 days of age to assess both creep and shrinkage. Results show that the age of concrete at the loading day is of paramount importance regarding the time‐dependent effects. These are most relevant during the first days of loading and tend to stabilize from the 112th day of loading onward. The time‐dependent girder's mid‐span deflection at the end of the 3.75 years did not exceed more than 50% of the initial deformation. Comparison of results with those obtained with Model Code 2010 and the current version of Eurocode 2 shows that these underestimate strains and deflections due to creep, mostly because the short‐term development of these effects, occurring during the first days of loading, are not adequately represented. On the contrary, a sound agreement between experimental and theoretical values, both in short and long term, was obtained using the Auperin et al. approach.
Long‐term behavior of slender long‐span precast prestressed high‐strength concrete girders
Structural Concrete
Fernandes, Paulo (Autor:in) / Cavaco, Eduardo (Autor:in) / do Carmo, Ricardo (Autor:in) / Maranha, Paulo (Autor:in) / Júlio, Eduardo (Autor:in)
Structural Concrete ; 25 ; 1571-1589
01.06.2024
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
Behavior of Two Long-Span High Strength Concrete Prestressed Bridge Girders
| British Library Conference Proceedings | 1996
Applications of High-Strength Concrete to Long-Span Prestressed Bridge Girders
| British Library Online Contents | 1995
Applications of High-Strength Concrete to Long-Span Prestressed Bridge Girders
| British Library Conference Proceedings | 1995