Assessment of the Behavior of Steel-Fiber Reinforced Concrete Produced with Different Ratios of Fine-to-Coarse Aggregate

Abstract

Aggregate is an important ingredient of concrete that affects both fresh and hardened properties of concrete. The properties of concrete can be enhanced or worsened by changing properties of aggregate, especially particle size distribution of aggregate. However, in the literature, the effects of particle size distribution of aggregate on the properties of concrete have been neglected for particularly Steel-Fiber Reinforced Concrete (SFRC) although packing is a very important aspect for SFRC quality. Thus, this study investigates the effects of changing particle size distribution and maximum size (Dmax) of aggregate on the workability and mechanical properties of SFRC. With this aim, three gradations and two Dmax were used to produce SFRC mixtures with constant cement dosages and water/cement ratios. Totally, nine different concrete series were tested. To observe the properties of fresh concrete, Slump and Ve-Be tests were performed. The compressive, splitting tensile and flexural strengths of concretes were also evaluated, and the toughness of the SFRC specimens was calculated. Based on the test results , it can be concluded that the ratio of fine-to-coarse aggregate, the void content between the aggregate particles and Dmax have remarkable effects on the properties of both fresh and hardened SFRC. In addition, the toughness of the SFRC specimens which has constant cement dosage, and water/cement ratios were influenced by those aspects of the aggregates.

Fresh Properties, Strength, and Durability of Fiber-Reinforced Geopolymer and Conventional Concrete: A Review

“…Fibers in concrete composites act as bridges within the concrete matrix through physical bond interactions. The bridging action through reinforcing fibers increases the energy required for a crack to propagate through concrete and enhances its crack resistance [ 7 ]. The impact of crack formation and growth on the mechanical properties and durability of concrete is effectively mitigated by the addition of reinforcing fibers [ 8 ].…”

“…The average space between fibers decreases as the fiber content increases, thereby limiting the initiation and propagation of cracks within the matrix. Steel fibers are the most investigated in terms of the effect on mechanical properties of concrete [ 7 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 ]. They generally create a stronger bond with the matrix, leading to higher flexural and tensile performances compared to other types of fibers.…”

“…Monitoring the workability of fresh concrete is necessary to ensure the attainment of sufficient hardened strength after construction. Ulas [ 7 ] reported a sudden decrease in workability when rigid steel fibers content increased to 1.5% within slag-fly ash concrete. High content of steel fibers in concrete pushes aggregates apart, causing slump values to decrease substantially.…”

Effect of steel macro fibers on engineering properties of copperslag‐concrete

“…Also the stiffness of the mixture varies depending upon the volume fraction and aspect ratio of the fibers. A major setback in normal concrete mixture is that, as the fiber content increases in the mixer it forms a web like structure pushing away the aggregates, which results in low slump values . Unlike normal concrete, the mixing time was increased ensuring homogenous mix, as the fiber network and efficient aggregate settlement to its corresponding cement paste increases the internal friction followed by mechanical interlocking due to the incorporation of copper slag.…”

“…A major setback in normal concrete mixture is that, as the fiber content increases in the mixer it forms a web like structure pushing away the aggregates, which results in low slump values. 25 Unlike normal concrete, the mixing time was increased ensuring homogenous mix, 26 as the fiber network and efficient aggregate settlement to its corresponding cement paste increases the internal friction followed by mechanical interlocking due to the incorporation of copper slag. Generally, during mixing steel fibers disperse or settle irregularly at the bottom of the specimen due to its high density.…”