Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Short-Term Effects of Moderate Temperatures on the Mechanical Properties of Steel and Macrosynthetic Fiber Reinforced Concretes
Fiber reinforced concrete (FRC) is a special type of concrete with improved mechanical properties due to the introduction of fibers. Macrosynthetic fibers have been recently proposed as structural reinforcement and further investigations are required to evaluate their performance in aggressive environments wherein their properties may change due to factors such as temperature.
This research examines the effect of moderate temperatures on the short-term behavior of pre-cracked and non pre-cracked FRC specimens with steel and polypropylene-based macrosynthetic fibers. A concrete type C30/37 was chosen to be as close as possible to common practice, as well as the fiber type and their content (2.1% and 0.7% respectively). The experimental campaign consists of 72 beams which were tested according to a modified procedure based on the standard EN 14651:2007 + A1:2007 in order to assess their residual flexural strengths at target temperatures (−15, 20 and 60 ℃). Additionally, 18 cubes were produced to perform compression strength tests at these environmental conditions. Slump, density, air content and compression strength at standard conditions were also tested to characterize the mixes. To guarantee that the interior of the specimen has reached the target temperature during the tests, all specimens were exposed 72 h at these target temperatures before testing. During the test, the variation of internal temperatures of the specimens was greatly reduced by means of a custom insulation system. Part of the analysed beams were pre-cracked at room temperature at the age of 28 days up to a crack opening equal to 0.5 mm. These pre-cracked beams were re-loaded again at the selected moderate temperatures to investigate the effect of the temperatures on large crack mouth opening displacements in already cracked elements when compared to uncracked elements.
The results obtained show differences in the behavior depending on the type of fiber. The steel and polypropylene fiber reinforced concretes investigated in this study maintained overall good residual strength values at the temperatures selected after 3 days of exposition to moderate temperatures.
Short-Term Effects of Moderate Temperatures on the Mechanical Properties of Steel and Macrosynthetic Fiber Reinforced Concretes
Fiber reinforced concrete (FRC) is a special type of concrete with improved mechanical properties due to the introduction of fibers. Macrosynthetic fibers have been recently proposed as structural reinforcement and further investigations are required to evaluate their performance in aggressive environments wherein their properties may change due to factors such as temperature.
This research examines the effect of moderate temperatures on the short-term behavior of pre-cracked and non pre-cracked FRC specimens with steel and polypropylene-based macrosynthetic fibers. A concrete type C30/37 was chosen to be as close as possible to common practice, as well as the fiber type and their content (2.1% and 0.7% respectively). The experimental campaign consists of 72 beams which were tested according to a modified procedure based on the standard EN 14651:2007 + A1:2007 in order to assess their residual flexural strengths at target temperatures (−15, 20 and 60 ℃). Additionally, 18 cubes were produced to perform compression strength tests at these environmental conditions. Slump, density, air content and compression strength at standard conditions were also tested to characterize the mixes. To guarantee that the interior of the specimen has reached the target temperature during the tests, all specimens were exposed 72 h at these target temperatures before testing. During the test, the variation of internal temperatures of the specimens was greatly reduced by means of a custom insulation system. Part of the analysed beams were pre-cracked at room temperature at the age of 28 days up to a crack opening equal to 0.5 mm. These pre-cracked beams were re-loaded again at the selected moderate temperatures to investigate the effect of the temperatures on large crack mouth opening displacements in already cracked elements when compared to uncracked elements.
The results obtained show differences in the behavior depending on the type of fiber. The steel and polypropylene fiber reinforced concretes investigated in this study maintained overall good residual strength values at the temperatures selected after 3 days of exposition to moderate temperatures.
Short-Term Effects of Moderate Temperatures on the Mechanical Properties of Steel and Macrosynthetic Fiber Reinforced Concretes
RILEM Bookseries
Serna, Pedro (Herausgeber:in) / Llano-Torre, Aitor (Herausgeber:in) / Martí-Vargas, José R. (Herausgeber:in) / Navarro-Gregori, Juan (Herausgeber:in) / Caballero-Jorna, Marta (Autor:in) / Roig-Flores, Marta (Autor:in) / Serna, Pedro (Autor:in)
RILEM-fib International Symposium on Fibre Reinforced Concrete ; 2021 ; Valencia, Spain
Fibre Reinforced Concrete: Improvements and Innovations II ; Kapitel: 20 ; 220-231
RILEM Bookseries ; 36
05.09.2021
12 pages
Aufsatz/Kapitel (Buch)
Elektronische Ressource
Englisch
| British Library Online Contents | 2018
Flexural properties of steel fiber-reinforced concretes at low temperatures
| Online Contents | 1998