Effect of Steel Fibers on Bond Performance of Steel Bars in NSC and HSC under Load Reversals

2007 ◽  
Vol 19 (10) ◽  
pp. 864-873 ◽  
Author(s):  
M. H. Harajli ◽  
O. Gharzeddine
Keyword(s):  
Steel Fibers ◽  
Bond Performance ◽  
Steel Bars

Degradation model of bond performance between deteriorated concrete and corroded deformed steel bars

2016 ◽  
Vol 119 ◽  
pp. 89-95 ◽  
Author(s):  
Yuan-Zhou Wu ◽  
Heng-Lin Lv ◽  
Shu-Chun Zhou ◽  
Zhong-Nian Fang
Keyword(s):  
Degradation Model ◽  
Bond Performance ◽  
Steel Bars

scholarly journals Bond Behavior of Reinforcing Steel Bars in Thermal Insulation Concrete Exposed to Freeze-Thaw Cycles

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Jinsong Tu ◽  
Ming Zhou ◽  
Yuanzhen Liu ◽  
Y. Frank Chen
Keyword(s):  
Mechanical Properties ◽  
Thermal Insulation ◽  
Ct Scanning ◽  
Reinforcing Steel ◽  
Freezing And Thawing ◽  
Scanning Method ◽  
Bond Behavior ◽  
Freeze Thaw ◽  
Bond Performance ◽  
Steel Bars

An experimental study on the bond behavior of reinforcing steel bars in thermal insulation concrete (TIC) mixed with glazed hollow beads (GHBs) and exposed to freeze-thaw (F-T) cycles was carried out. In order to investigate the effects of GHBs on freezing and thawing, the experimental results were compared with those of normal concrete (NC). The comparison shows that, after 300 F-T cycles, both bond behavior and mechanical properties of the TIC specimens are better than those of the NC specimens. Furthermore, in order to investigate the mechanism of frost effect on TIC, the CT scanning method was used to investigate the evolution of the inner structure of a TIC specimen exposed to F-T cycles. The CT images show that the deterioration of bond performance and mechanical properties of the TIC specimen appears to be caused by the increase of micropores in the TIC.

Study on Restrained Expansive Deformation of Steel Fiber Reinforced Self-Stressing Concrete

2008 ◽  
Vol 385-387 ◽  
pp. 305-308
Author(s):  
Huan An He ◽  
Cheng Kui Huang
Keyword(s):  
Prestressed Concrete ◽  
High Performance ◽  
Steel Fiber ◽  
High Performance Concrete ◽  
Steel Fibers ◽  
Fiber Reinforced ◽  
The Troubles ◽  
Steel Bar ◽  
Steel Bars ◽  
Steel Fiber Concrete

A new sort of high performance concrete is introduced which combines most advantages of prestressed concrete and steel fiber concrete, named steel fiber reinforced self-stressing concrete(SFFRSSC for short). Self-stressing concrete is actually a kind of expansive concrete which self-stresses, namely pre-compressive stresses, are induced by dint of some restrictions generally provided by steel bars to concrete expansion after hydration of expansive cement. As a result of chemical reaction, concrete archived prestresses by itself different from mechanical prestressed concrete, so called self-stressing concrete. By distributing short-cut steel fibers into self-stressing concrete at random, prestresses( self-stress) are created in concrete under combined restriction of steel bars and steel fibers. Thank to the pre-stresses tensile strength of concrete are significantly increased as well as cracking strength. In addition, expansive deformation of SFFRSSC can compensate the shrinkage of concrete to decrease shrinkage crack, and the steel fibers play an important role in post-crack behavior. On the other hand, self-stressing concrete can avoid the troubles of construction compared with conventional mechanical prestressed concrete. For purpose of understanding the properties of SFFRSSC, in this paper some researches were carried out to investigate the special expansive behaviors of restrained expansive deformation with restriction of steel bar as well as steel fiber. The test results indicated that steel bar and steel fiber both provide effective restrict to self-stressing concrete as result of forming prestresses in concrete.

Study on Losses of Self-Stress Created by Steel Fiber Reinforced Self-Stressing Concrete

2013 ◽  
Vol 438-439 ◽  
pp. 300-303 ◽  
Author(s):  
Bo Xin Wang ◽  
He Nan Jin ◽  
Teng Man
Keyword(s):  
Steel Fiber ◽  
Theoretical Models ◽  
Steel Fibers ◽  
Fiber Reinforced ◽  
Steel Bars ◽  
The Matrix ◽  
The Stability

Based on the 9-year-experiment of self-stressing concrete (SSC for short), the stability of self-stress caused by steel bars and steel fibers is investigated. The results show that the losses of self-stress are only from 0.6 MPa to 1.2 MPa during 2.5 years. Meanwhile the matrix of steel fiber reinforced self-stressing concrete (SFRSSC for short) has the characteristic of secondary expansion. Finally, according to the existing theoretical models, formulas of the losses of self-stress created by SFRSSC are obtained.

scholarly journals Bond Performance of Sand-Coated BFRP Bars to Concrete

2019 ◽  
Vol 8 (10) ◽  
pp. 1330-1335
Keyword(s):  
Bond Strength ◽  
Test Results ◽  
Basalt Fibre ◽  
Bond Failure ◽  
Bond Behaviour ◽  
Bond Performance ◽  
Reinforced Polymer ◽  
Steel Bars ◽  
Fibre Reinforced Polymer ◽  
Average Bond

This paper presents an experimental study on the bond behaviour of sand-coated basalt fibre reinforced polymer (BFRP) bars and conventional steel bars of 10mm- diameter. The bond strength of these bars were determined according to ASTM D7913/D7913M-14 standards. The pullout specimens consisted of BFRP bars embedded in concrete cubes (200mm on each side) with the compressive strength of 40MPa were constructed. The pullout test results contain the bond failure mode, the average bond strength , the slip at the free and loaded end, and the bond stress-slip relationship curves.The test results showed that the bond strength of sand-coated BFRP bars was about 70% that of the steel bars.

scholarly journals Bond to Bar Reinforcement of PET-Modified Concrete Containing Natural or Recycled Coarse Aggregates

Environments ◽  
2022 ◽  
Vol 9 (1) ◽  
pp. 8
Author(s):  
Joseph J. Assaad ◽  
Jamal M. Khatib ◽  
Rawan Ghanem
Keyword(s):  
Steel Fibers ◽  
Recycled Aggregates ◽  
Test Results ◽  
Coarse Aggregates ◽  
Water To Cement Ratio ◽  
Concrete Production ◽  
Steel Bars ◽  
The Matrix ◽  
Concrete Mechanical Properties ◽  
Mixing Water

The use of post-consumer plastics in concrete production is an ideal alternative to dispose of such wastes while reducing the environmental impacts in terms of pollution and consumption of natural resources and energy. This paper investigates different approaches (i.e., reducing water-to-cement ratio and incorporating steel fibers or polymeric latexes) that compensate for the detrimental effect of waste plastics on the drop in concrete mechanical properties including the bond to embedded steel bars. The polyethylene terephthalate (PET) wastes used in this study were derived from plastic bottles that were shredded into small pieces and added during concrete batching at 1.5% to 4.5%, by total volume. Test results showed that the concrete properties are degraded with PET additions, given their lightweight nature and poor characteristic strength compared to aggregate particles. The threshold PET volumetric rates are 4.5% and 3% for concrete made using natural or recycled aggregates, respectively. The reduction of w/c from 0.55 to 0.46 proved efficient to refine the matrix porosity and reinstate the concrete performance. The incorporation of 0.8% steel fibers (by volume) or 15% polymers (by mixing water) were appropriate to enhance the bridging phenomena and reduce the propagation of cracks during the pullout loading of steel bars.

Influence of specimen dimensions and reinforcement corrosion on bond performance of steel bars in concrete

2020 ◽  
Vol 23 (9) ◽  
pp. 1759-1771
Author(s):  
Bai Zhang ◽  
Hong Zhu ◽  
Jun Chen ◽  
Ou Yang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Experimental Results ◽  
Reinforcement Corrosion ◽  
Element Analysis ◽  
Bond Slip ◽  
Bond Performance ◽  
Concrete Deterioration ◽  
Pull Out ◽  
Steel Bars

To study the deterioration of bond performance between concrete and corroded steel bars with designed corrosion levels of 0%, 0.5%, 1.0%, 2.0%, 5.0%, 8.0%, and 10.0%, pull-out tests were performed on cube specimens with the dimensions of 10 D × 10 D × 10 D, where D is the diameter of longitudinal rebars ( D = 14, 20, and 25 mm, respectively). The experimental results indicated that with the specimen dimensions increased, the expansive cracks induced by corrosion products appeared earlier and the maximum expansive cracking width was larger at the same corrosion levels. The bond strength and the initial bond stiffness first increased and then dramatically decreased as the concrete deterioration and reinforcement corrosion levels increased for each specimen dimension, whereas the specimens with the larger diameter ( D = 25 mm) were more sensitive to the corrosion than those with the smaller diameter ( D = 14, 20 mm). The free-end slip and the energy dissipation for each specimen dimensions, which decreased slowly with increasing corrosion levels before the corrosion-induced cracks and then weakened rapidly when the corrosion-induced cracks appeared, was almost independent of the influence on corrosion levels after the corrosion-induced cracks appeared. Based on the experimental results, a simplified expression for the calculation of residual bond stress and an empirical model of the bond–slip constitutive equation that considers the influence of reinforcement corrosion were proposed, which can be used in finite element analysis of corroded reinforced concrete.

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