The blast resistance of structures used in buildings needs to be investigated due to the increased threat of a terrorist attack. The damage done by Composition B or Powergel to steel fibre reinforced reactive powder c...The blast resistance of structures used in buildings needs to be investigated due to the increased threat of a terrorist attack. The damage done by Composition B or Powergel to steel fibre reinforced reactive powder concrete （SFRPC） panels and ordinary reinforced concrete （RC） panels of equivalent static flexural strength is compared. A 0. 5 kg charge was detonated at a distance of 0. 1 m from the 1. 3 m × 1. 0 m × 0. 1 m （thick） panels, which were simply supported and spaning 1.3 m. Dynamic displacement measurements, high-speed video recording and visual examination of the panels for spall and breach were undertaken. The SFRPC panels withstood the bare charge blast better than the reinforced ordinary concrete panels. Neither type of panel was breached using a O. 5 kg charge, The RC panel exhibited more spalling when Composition B was used. Under successive Composition B loading conditions, the RC panel was breached. In comparison the SFRPC panel was not breached. Exposure to fragmenting charge loading conditions confirmed these performance differences between the SFRPC panel and the reinforced ordinary concrete panel.展开更多
Based on an engineering background of a deep tunneling in weak rocks, the numerical modeling is used to compare different support schemes of tunnel at great depth in this paper. Focused on the general behaviors of wea...Based on an engineering background of a deep tunneling in weak rocks, the numerical modeling is used to compare different support schemes of tunnel at great depth in this paper. Focused on the general behaviors of weak rocks at great depth, a tunneling scheme with rock bolting and steel fibre reinforced sprayed concrete is proposed. This scheme is practiced successfully at a deep tunnel in weak rocks in Coal Mine No 10 of Hebi Coal Mining Administration.展开更多
This paper reports investigation conducted to study the fatigue performance of steel fibre reinforced concrete (SFRC) containing fibres of mixed aspect ratio. An extensive experimental program was conducted in which 9...This paper reports investigation conducted to study the fatigue performance of steel fibre reinforced concrete (SFRC) containing fibres of mixed aspect ratio. An extensive experimental program was conducted in which 90 flexural fatigue tests were carried out at different stress levels on size 500 mm×100 mm×100 mm SFRC specimens respectively containing 1.0%, 1.5% and 2.0% volume fraction of fibres. About 36 static flexural tests were also conducted to determine the static flexural strength prior to fatigue testing. Each volume fraction of fibres incorporated corrugated mixed steel fibres of size 0.6 mm×2.0 mm×25 mm and 0.6 mm×2.0 mm×50 mm in ratio 50:50 by weight. The results are presented both as S-N relationships, with the maximum fatigue stress expressed as a percentage of the strength under static loading, and as relationships between actually applied fatigue stress and number of loading cycles to failure. Two-million-cycle fatigue strengths of SFRC containing different volume fractions of mixed fibres were obtained and compared with plain concrete.展开更多
The results of an analytical investigation of the flexural behaviour of Steel Fibre Reinforced Concrete （SFRC） beams are presented. The complete response of the SFRC beams under displacement controlled static loadin...The results of an analytical investigation of the flexural behaviour of Steel Fibre Reinforced Concrete （SFRC） beams are presented. The complete response of the SFRC beams under displacement controlled static loading was obtained using nonlinear Finite Element （FE） techniques implemented with the help of ATENA 2D soRware. Issues relating to the behaviour of SFRC which have a direct bearing on the FE modelling are discussed with relevance to the software employed for the nonlinear analysis. Constitutive models amenable to numerical analysis for steel fibrous concrete are presented. The structural response throughout the loading regime was captured in terms of the load-deflection behaviour, which in addition to the post-peak response characterized the failure mode of the test beams. The crack patterns at crack initiation and at the end of the tests were also recorded. Experimental results from the specimens of two other investigators were used as control values for this investigation. The response of the specimens of this investigation was evaluated in terms of initial tangent stiffness, peak loads and toughness. Good match was obtained between the results from this investigation and corresponding experimentally obtained values, wherever available. The influence of the fibre content is reflected in the observed trends in peak loads, deflection at peak loads and toughness, which are in broad agreement with known behavioral patterns of SFRC.展开更多
文摘The blast resistance of structures used in buildings needs to be investigated due to the increased threat of a terrorist attack. The damage done by Composition B or Powergel to steel fibre reinforced reactive powder concrete （SFRPC） panels and ordinary reinforced concrete （RC） panels of equivalent static flexural strength is compared. A 0. 5 kg charge was detonated at a distance of 0. 1 m from the 1. 3 m × 1. 0 m × 0. 1 m （thick） panels, which were simply supported and spaning 1.3 m. Dynamic displacement measurements, high-speed video recording and visual examination of the panels for spall and breach were undertaken. The SFRPC panels withstood the bare charge blast better than the reinforced ordinary concrete panels. Neither type of panel was breached using a O. 5 kg charge, The RC panel exhibited more spalling when Composition B was used. Under successive Composition B loading conditions, the RC panel was breached. In comparison the SFRPC panel was not breached. Exposure to fragmenting charge loading conditions confirmed these performance differences between the SFRPC panel and the reinforced ordinary concrete panel.
文摘Based on an engineering background of a deep tunneling in weak rocks, the numerical modeling is used to compare different support schemes of tunnel at great depth in this paper. Focused on the general behaviors of weak rocks at great depth, a tunneling scheme with rock bolting and steel fibre reinforced sprayed concrete is proposed. This scheme is practiced successfully at a deep tunnel in weak rocks in Coal Mine No 10 of Hebi Coal Mining Administration.
基金Project supported by the Indian Council for Cultural Relations,India
文摘This paper reports investigation conducted to study the fatigue performance of steel fibre reinforced concrete (SFRC) containing fibres of mixed aspect ratio. An extensive experimental program was conducted in which 90 flexural fatigue tests were carried out at different stress levels on size 500 mm×100 mm×100 mm SFRC specimens respectively containing 1.0%, 1.5% and 2.0% volume fraction of fibres. About 36 static flexural tests were also conducted to determine the static flexural strength prior to fatigue testing. Each volume fraction of fibres incorporated corrugated mixed steel fibres of size 0.6 mm×2.0 mm×25 mm and 0.6 mm×2.0 mm×50 mm in ratio 50:50 by weight. The results are presented both as S-N relationships, with the maximum fatigue stress expressed as a percentage of the strength under static loading, and as relationships between actually applied fatigue stress and number of loading cycles to failure. Two-million-cycle fatigue strengths of SFRC containing different volume fractions of mixed fibres were obtained and compared with plain concrete.
文摘The results of an analytical investigation of the flexural behaviour of Steel Fibre Reinforced Concrete （SFRC） beams are presented. The complete response of the SFRC beams under displacement controlled static loading was obtained using nonlinear Finite Element （FE） techniques implemented with the help of ATENA 2D soRware. Issues relating to the behaviour of SFRC which have a direct bearing on the FE modelling are discussed with relevance to the software employed for the nonlinear analysis. Constitutive models amenable to numerical analysis for steel fibrous concrete are presented. The structural response throughout the loading regime was captured in terms of the load-deflection behaviour, which in addition to the post-peak response characterized the failure mode of the test beams. The crack patterns at crack initiation and at the end of the tests were also recorded. Experimental results from the specimens of two other investigators were used as control values for this investigation. The response of the specimens of this investigation was evaluated in terms of initial tangent stiffness, peak loads and toughness. Good match was obtained between the results from this investigation and corresponding experimentally obtained values, wherever available. The influence of the fibre content is reflected in the observed trends in peak loads, deflection at peak loads and toughness, which are in broad agreement with known behavioral patterns of SFRC.
