scholarly journals Influence of the cementitious matrix on the behavior of fiber reinforced concrete

2020 ◽  
Vol 13 (3) ◽  
pp. 543-562
Author(s):  
A. M. LEITE ◽  
A. L. de CASTRO
Keyword(s):  
Reinforced Concrete ◽  
Steel Fiber ◽  
High Strength ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Shrinkage Cracking ◽  
Cementitious Matrix ◽  
Plastic Shrinkage ◽  
Fresh State ◽  
Hardened State

Abstract One of the main purposes of the addition of fibers to the concrete is the control of the plastic shrinkage cracking in the fresh state and the increase of the post-crack resistance in the hardened state. The cementitious matrix is one of the factors that influences the performance of fiber reinforced concrete, interfering in the fluidity of the mixture and in the adhesion between fiber and matrix. In this context, the present paper evaluates the behavior of two concrete, one of conventional strength and another of high-strength, without fiber and with a content of 1%, by volume, of fiber, being used steel fiber and macro-polymeric fiber. For this, the mechanical properties of the concrete were evaluated in the hardened state by the tests of compressive strength, Barcelona, flexure of prisms and punching of plates. From the experimental results, statistically analyzed, there were significant changes in toughness and residual strength due to change in the cementitious matrix. Finally, an equivalence of performance between the fibers as to the toughness was observed, with the change of the cementitious matrix.

scholarly journals Optimization of the Fine to Coarse Aggregate Ratio for the Workability and Mechanical Properties of High Strength Steel Fiber Reinforced Concretes

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5202
Author(s):  
Mohammad Iqbal Khan ◽  
Wasim Abbass ◽  
Mohammad Alrubaidi ◽  
Fahad K. Alqahtani
Keyword(s):  
Mechanical Properties ◽  
Reinforced Concrete ◽  
Flexural Strength ◽  
Coarse Aggregate ◽  
Steel Fiber ◽  
High Strength ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Fresh State

High-strength concrete is used to provide quality control for concrete structures, yet it has the drawback of brittleness. The inclusion of fibers improves the ductility of concrete but negatively affects the fresh properties of fiber-reinforced concrete. The effects of different fine to coarse aggregate ratios on the fresh and hardened properties of steel fiber reinforced concrete were investigated in this study. Mixtures were prepared with various fine to coarse aggregate (FA/CA) ratios incorporating 1% steel fiber content (by volume) at constant water to cement ratio. The workability, unit weight, and temperature of the concrete in the fresh state, and the mechanical properties of steel-fiber-reinforced concrete (SFRC) were investigated. The inclusion of fiber in concrete influenced the mobility of concrete in the fresh state by acting as a barrier to the movement of coarse aggregate. It was observed that the concrete with an FA/CA ratio above 0.8 showed better flowability in the fresh state, whilst an above 0.9 FA/CA ratio requires excessive superplasticizer to maintain the flowability of the mixtures. The compressive and flexural strength of SFRC increased with an increase in the FA/CA ratio by around 10% and 28%, respectively. Experimental values of compressive strength and flexural strength showed good agreement, however, modulus of elasticity demonstrated slightly higher values. The experimentally obtained measurements of the mechanical properties of SFRC conformed reasonably well with the available existing prediction equations, and further enabled establishing predictive isoresponse interactive equations within the scope of the investigation domain.

scholarly journals Experimental Study on Shear Behavior of Steel Fiber Reinforced Concrete Beams with High-Strength Reinforcement

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1682 ◽  
Author(s):  
Jun Zhao ◽  
Jingchao Liang ◽  
Liusheng Chu ◽  
Fuqiang Shen
Keyword(s):  
Reinforced Concrete ◽  
Crack Width ◽  
Steel Fiber ◽  
High Strength ◽  
Shear Behavior ◽  
Fiber Reinforced Concrete ◽  
Reinforced Concrete Beams ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Diagonal Crack

Many researchers have performed experimental and theoretical studies on the shear behavior of steel fiber reinforced concrete (SFRC) beams with conventional reinforcement; few studies involve the shear behavior of SFRC beams with high-strength reinforcement. In this paper, the shear test of eleven beams with high-strength reinforcement was carried out, including eight SFRC beams and three reinforced concrete (RC) beams. The load-deflection curve, concrete strain, stirrup strain, diagonal crack width, failure mode and shear bearing capacity of the beams were investigated. The test results show that steel fiber increases the stiffness, ultimate load and failure deformation of the beams, but the increase effect of steel fiber decreases with the increase of stirrup ratio. After the diagonal crack appears, steel fiber reduces the concrete strains of the diagonal section, stirrup strains and diagonal crack width. In addition, steel fiber reduces crack height and increases crack number. Finally, the experimental values of the shear capacities were compared with the values calculated by CECS38:2004 and ACI544.4R, and the equation of shear capacity in CECS38:2004 was modified to effectively predict the shear capacities of SFRC beams with high-strength reinforcement.

scholarly journals The change in impermeability of steel fiber reinforced concrete with high strength cement-sand matrix at heating

2020 ◽  
Vol 17 (1) ◽  
pp. 150-155
Author(s):  
V. A. Dorf ◽  
◽  
R. O. Krasnovskij ◽  
D. E. Kapustin ◽  
P. S. Sultygova ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Steel Fiber ◽  
Heating Temperature ◽  
High Strength ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Fiber Concrete ◽  
The Matrix ◽  
Steel Fiber Concrete

The paper considers the effects of high temperatures in case of fire on the change in impermeability of steel fiber reinforced concrete having a high-strength cement-sand matrix and various content of fiber of different types, sizes, and strength. It is shown that in the temperature range from 20° to 1100° C in the diagram “Heating temperature - impermeability class», the matrix and steel fiber concrete(SFC) have a S-shaped character, and in case of heating temperature of over 100 °C, there comes a distinct decrease in impermeability.

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