Over the past decades, the effect of elevated temperatures on the mechanical properties of concrete has received significant attention because of the importance for fireproof design, safety evaluation and repair of fire damaged constructions. However, very few researches have been dedicated to the consequences of water re-curing of a thermally damaged concrete. In this paper, the effect of elevated temperatures and water re-curing on the mechanical response of two hybrid fiber reinforced concretes was investigated. For the first hybrid reinforced mix, long hooked-end and medium hooked-end steel fibers were adopted, as well as high strength short wave shaped steel fibers. In the second mix, polypropylene fibers substituted the short-wave shaped steel fibers. The mechanical behavior in compression was studied by measuring the stress-strain response. The elevated temperatures above 200 degrees C decreased: Young's modulus, compressive strength and toughness of the hybrid fiber reinforced concretes. The stable crack growth stage was reduced with the increase of the temperature above 200 degrees C, with an extension of the unstable crack growth stage for both kinds of hybrid fiber reinforced concrete. Water re-curing partially recovered Young's modulus, compressive strength, toughness, and extended the stable crack growth. An existing model was modified for predicting the stress-strain response of thermally damaged hybrid fiber reinforced concrete.

Effects of elevated temperature and water re-curing on the compression behavior of hybrid fiber reinforced concrete

Biolzi, L;Carvelli, V
2023-01-01

Abstract

Over the past decades, the effect of elevated temperatures on the mechanical properties of concrete has received significant attention because of the importance for fireproof design, safety evaluation and repair of fire damaged constructions. However, very few researches have been dedicated to the consequences of water re-curing of a thermally damaged concrete. In this paper, the effect of elevated temperatures and water re-curing on the mechanical response of two hybrid fiber reinforced concretes was investigated. For the first hybrid reinforced mix, long hooked-end and medium hooked-end steel fibers were adopted, as well as high strength short wave shaped steel fibers. In the second mix, polypropylene fibers substituted the short-wave shaped steel fibers. The mechanical behavior in compression was studied by measuring the stress-strain response. The elevated temperatures above 200 degrees C decreased: Young's modulus, compressive strength and toughness of the hybrid fiber reinforced concretes. The stable crack growth stage was reduced with the increase of the temperature above 200 degrees C, with an extension of the unstable crack growth stage for both kinds of hybrid fiber reinforced concrete. Water re-curing partially recovered Young's modulus, compressive strength, toughness, and extended the stable crack growth. An existing model was modified for predicting the stress-strain response of thermally damaged hybrid fiber reinforced concrete.
2023
Concrete
Hybrid fibers
Elevated temperature
Water re -curing
Compression behavior
File in questo prodotto:
File Dimensione Formato  
Carvelli_Journal of Building Engineering-2023.pdf

Accesso riservato

Descrizione: Carvelli et al_Journal of Building Engineering-2023
: Publisher’s version
Dimensione 2.76 MB
Formato Adobe PDF
2.76 MB Adobe PDF   Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11311/1256437
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 8
  • ???jsp.display-item.citation.isi??? 2
social impact