HYBRID STEEL FIBER REINFORCED CONCRETES: EFFECTS OF ELEVATED TEMPERATURE AND WATER RE-CURING ON THE MECHANICAL PERFORMANCE
Topic(s) : Industrial applications
Co-authors :
Fengzhen HE (CHINA), Luigi BIOLZI , Valter CARVELLI (ITALY)Abstract :
There is a general agreement on the favorable influence of fiber hybridization on the mechanical performance of fiber reinforced concrete [1]. The hybrid fiber reinforcement can have a synergistic effect, at different scales, on enhancing the mechanical properties of concrete. However, the effect of elevated temperatures [2] and water re-curing on thermally damaged fiber reinforcement concrete have been barely studied. These factors are of considerable importance for fire resistance design and safety assessment of fiber reinforced concrete components.
Therefore, this study investigated the effect of elevated temperatures and water re-curing on the mechanical response of hybrid steel fiber reinforced concretes. The study is summarized here, with its contents divided into two parts. The first part examines the effect of various steel fiber hybridizations on the compression, tension [3], shear and fracture behavior [4] of fiber reinforced concretes at room temperature. The second part details the effects of elevated temperature and water re-curing on the compression performance [5] and fracture process [6] of hybrid steel fiber reinforced concretes.
The results indicated an increase of the damage degree as the temperature increased, estimated by the ultrasonic pulse velocity method. However, a considerable reduction was obtained after water re-curing. Exposure to temperatures exceeding 200°C had a negative impact on fracture toughness. The exposition to elevated temperatures and water re-curing modified the fracture process of hybrid fiber reinforced concrete. For temperatures above 200 ◦C, the branching fracture appeared around the peak load level. Water re-curing reduced the branching effect and prevented the formation of multiple cracks in thermally damaged hybrid fiber reinforced concrete.
References
1. Banthia, Majdzadeh, Wu, Bindiganavile, 2014, https://doi.org/10.1016/j.cemconcomp.2013.10.018
2. Chen, Liu, 2004, https://doi.org/10.1016/j.cemconres.2003.11.010
3. He, Biolzi, Carvelli, 2022, https://doi.org/10.1617/s11527-022-02020-9
4. He, Biolzi, Carvelli, Monteiro, 2022, https://doi.org/10.1016/j.compstruct.2022.116005
5. He, Biolzi, Carvelli, 2023, https://doi.org/10.1016/j.jobe.2023.106034
6. He, Biolzi, Carvelli, 2022, https://doi.org/10.1016/j.engfracmech.2022.108885
Therefore, this study investigated the effect of elevated temperatures and water re-curing on the mechanical response of hybrid steel fiber reinforced concretes. The study is summarized here, with its contents divided into two parts. The first part examines the effect of various steel fiber hybridizations on the compression, tension [3], shear and fracture behavior [4] of fiber reinforced concretes at room temperature. The second part details the effects of elevated temperature and water re-curing on the compression performance [5] and fracture process [6] of hybrid steel fiber reinforced concretes.
The results indicated an increase of the damage degree as the temperature increased, estimated by the ultrasonic pulse velocity method. However, a considerable reduction was obtained after water re-curing. Exposure to temperatures exceeding 200°C had a negative impact on fracture toughness. The exposition to elevated temperatures and water re-curing modified the fracture process of hybrid fiber reinforced concrete. For temperatures above 200 ◦C, the branching fracture appeared around the peak load level. Water re-curing reduced the branching effect and prevented the formation of multiple cracks in thermally damaged hybrid fiber reinforced concrete.
References
1. Banthia, Majdzadeh, Wu, Bindiganavile, 2014, https://doi.org/10.1016/j.cemconcomp.2013.10.018
2. Chen, Liu, 2004, https://doi.org/10.1016/j.cemconres.2003.11.010
3. He, Biolzi, Carvelli, 2022, https://doi.org/10.1617/s11527-022-02020-9
4. He, Biolzi, Carvelli, Monteiro, 2022, https://doi.org/10.1016/j.compstruct.2022.116005
5. He, Biolzi, Carvelli, 2023, https://doi.org/10.1016/j.jobe.2023.106034
6. He, Biolzi, Carvelli, 2022, https://doi.org/10.1016/j.engfracmech.2022.108885