Combined effect of nano-SiO2 particles and steel fibers on flexural properties of concrete composite containing fly ash

AbstractThis paper presents an experimental study to evaluate the combined effect of nano-SiO2 particles and steel fibers on flexural properties of concrete composites containing fly ash. In this study, five different nano-SiO2 contents (1%, 3%, 5%, 7%, and 9%) and five different steel fiber contents (0.5%, 1%, 1.5%, 2%, and 2.5%) were used. The results indicate that addition of nano-SiO2 and steel fibers decreases the workability of the concrete composites containing fly ash, and both the slump and slump flow decrease gradually with the increase in nano-SiO2 and steel fiber content. Besides, the addition of nano-SiO2 can greatly increase the flexural strength and flexural modulus of elasticity of concrete composites containing fly ash. There is a tendency for the increase in the flexural strength flexural modulus of elasticity with an increase in the nano-SiO2 content when the nano-SiO2 content is below 5%, while both of the two flexural parameters begin to decrease after the nano-SiO2 content above 5%. Furthermore, steel fibers have great improvement on the flexural properties of concrete composites containing fly ash and nano-particles. The flexural strength and flexural modulus of elasticity of concrete composites containing fly ash and nano-SiO2 are more than those of the concrete composite without steel fibers. Both of the two flexural parameters increase with the increase in steel fiber content when the steel fiber content is below 2%, while the flexural parameters begin to decrease after the steel fiber content is above 2%.

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Durability of Steel Fiber-Reinforced Concrete Containing SiO2 Nano-Particles

Materials ◽

10.3390/ma12132184 ◽

2019 ◽

Vol 12 (13) ◽

pp. 2184 ◽

Cited By ~ 18

Author(s):

Peng Zhang ◽

Qingfu Li ◽

Yuanzhao Chen ◽

Yan Shi ◽

Yi-Feng Ling

Keyword(s):

Steel Fiber ◽

Fiber Content ◽

Steel Fibers ◽

Nano Particles ◽

Cracking Resistance ◽

Water Permeation ◽

Nano Sio2 ◽

Carbonation Resistance ◽

Sio2 Particles ◽

Durability Of Concrete

An experimental study was conducted to investigate the effect ofnano-SiO2 and steel fiber content on the durability of concrete. Five different dosages of nano-SiO2 particles and five volume dosages of steel fiber were used. The durability of concretes includes permeability resistance, cracking resistance, carbonation resistance, and freezing-thawing resistance, and these were evaluated by the water permeation depth, number of cracks, total cracking area per unit area of the specimens, carbonation depth of the specimens, and the relative dynamic elastic modulus of the specimens after freezing-thawing cycles, respectively. The results indicate that the addition of nano-SiO2 particles significantly improves the durability of concrete when the content of nano-SiO2 is limited within a certain range. With the increase of nano-SiO2 content, the durability of concrete first increases and then decreases. An excessive number of nano-SiO2 particles could have an adverse effect on the durability of the concrete. The addition of the correct amount of steel fibers improves the carbonation resistance of concrete containing nano-particles, but excessive steel fiber reduces the carbonation resistance. Moreover, the addition of steel fibers reduces the permeability resistance of concrete containing nano-particles. The incorporation of steel fiber enhanced the freezing-thawing resistance and cracking resistance of concrete containing nano-particles. With increasing steel fiber content, the freezing-thawing resistance of the concrete containing nano-particles increases, and the cracking resistance of the concrete decreases gradually.

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Compressive Strength and Flexural Properties of High Performance Nano-Binder Cementitious Composites

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.275-277.2064 ◽

2013 ◽

Vol 275-277 ◽

pp. 2064-2068 ◽

Cited By ~ 1

Author(s):

Xiang Gao ◽

Qing Hua Li ◽

Shi Lang Xu

Keyword(s):

Mechanical Properties ◽

Compressive Strength ◽

High Performance ◽

Flexural Properties ◽

Cementitious Composites ◽

Nano Sio2 ◽

The Matrix ◽

Average Crack ◽

Sio2 Particles ◽

Pva Fiber

High performance nano-binder cementitious composites (HPNCC) are ultra-ductile fiber reinforced cementitious composites with special matrix. The compressive strength and flexural properties of HPNCC containing nano-SiO2 particles were investigated at age of 3d, 7d, 14d and 28d. According to the results, HPNCC exhibited excellent mechanical properties in the test. The compressive strength, flexural strength and first crack strain of HPNCC were all increased obviously at early age except the ultimate strain. In the flexural test, both crack extension width and the number of fine cracks decrease along with the curing age. However, the average crack spacing has no remarkable changes. Nano-SiO2 particles in HPNCC acted as ultra-fine fillers and catalyzers to strengthen the interfacial bond between the matrix and PVA fiber which improved the mechanical properties and would make HPNCC be widely used in the engineering.

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Flexural properties of steel fiber types and reinforcement ratio for high-strength recycled concrete beams

Advances in Structural Engineering ◽

10.1177/1369433216683196 ◽

2017 ◽

Vol 20 (10) ◽

pp. 1512-1522 ◽

Cited By ~ 5

Author(s):

Hai-Long Zhang ◽

Chang-Chun Pei

Keyword(s):

Fly Ash ◽

Silica Fume ◽

Crack Width ◽

Coarse Aggregate ◽

Steel Fiber ◽

High Strength ◽

Recycled Concrete ◽

Steel Fibers ◽

Flexural Properties ◽

Recycled Coarse Aggregate

This article took fly ash and silica fume as cementing materials to replace part of cement and took recycled coarse aggregate to replace part of gravel to mix plain concrete and studied the flexural properties of the beams with high-strength steel fiber–recycled concrete by changing the types of steel fiber and reinforcement ratio. The results showed that fly ash and silica fume could improve strength and flexural capacity of the recycled concrete beam by filling micro-cracks of recycled coarse aggregate and reduce the development speed of deflection and crack width of the test beam. Steel fibers could significantly slow the development of deflection and crack width of the beams with high-strength recycled concrete, and the difference in end-structure could increase the flexural capacity of the beams in varying degrees. The article put forward theory of improving the bearing capacity of the beam with three kinds of steel fibers by introducing the influence factor of steel fiber end-structure.

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Behavior of Quarry Rock Dust, Fly Ash and Slag Based Geopolymer Concrete Columns Reinforced with Steel Fibers under Eccentric Loading

Applied Sciences ◽

10.3390/app11156740 ◽

2021 ◽

Vol 11 (15) ◽

pp. 6740

Author(s):

Rana Muhammad Waqas ◽

Faheem Butt

Keyword(s):

Fly Ash ◽

Concrete Cover ◽

Steel Fibers ◽

Structural Behavior ◽

Partial Replacement ◽

Geopolymer Concrete ◽

Fiber Reinforced ◽

Conventional Concrete ◽

Source Materials ◽

Rock Dust

Geopolymer concrete, also known as an earth-friendly concrete, has been under continuous study due to its environmental benefits and a sustainable alternative to conventional concrete construction. The supplies of many source materials, such as fly ash (FA) or slag (SG), to produce geopolymer concrete (GPC) may be limited; however, quarry rock dust (QRD) wastes (limestone, dolomite, or silica powders) formed by crushing rocks appear virtually endless. Although significant experimental research has been carried out on GPC, with a major focus on the mix design development, rheological, durability, and mechanical properties of the GPC mixes; still the information available on the structural behavior of GPC is rather limited. This has implications in extending GPC application from a laboratory-based technology to an at-site product. This study investigates the structural behavior of quarry-rock-dust-incorporated fiber-reinforced GPC columns under concentric and eccentric loading. In this study, a total of 20 columns with 200 mm square cross-section and 1000 mm height were tested. The FA and SG were used as source materials to produce GPC mixtures. The QRD was incorporated as a partial replacement (20%) of SG. The conventional concrete (CC) columns were prepared as the reference specimens. The effect of incorporating quarry rock dust as a replacement of SG, steel fibers, and loading conditions (concentric and eccentric loading) on the structural behavior of GPC columns were studied. The test results revealed that quarry rock dust is an adequate material that can be used as a source material in GPC to manufacture structural concrete members with satisfactory performance. The general performance of the GPC columns incorporating QRD (20%) is observed to be similar to that of GPC columns (without QRD) and CC columns. The addition of steel fibers considerably improves the loading capacity, ductility, and axial load–displacement behavior of the tested columns. The load capacities of fiber-reinforced GPC columns were about 5–7% greater in comparison to the CC columns. The spalling of concrete cover at failure was detected in all plain GPC columns, whereas the failure mode of all fiber-reinforced GPC columns is characterized with surface cracking leading to disintegration of concrete cover.

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