Flexural behaviour of pumice lightweight concrete reinforced with end-hooked steel fibres

The use of expanded clay aggregate (ECA) for developing lightweight concrete results in strength-reduction properties. However, the ECA-based concrete strength properties can be improved by adding steel fibre (SF), glass fibre mesh (GFM) and multi-walled nano-carbon tubes (MWCNT). The combined effect of MWCNT, GFM, SF and ECA-based concrete and its strength properties is still unexplored. It is worth drawing a logical conclusion concerning the impact on the strength of concrete by incorporating the materials mentioned above. Two-stage expanded clay aggregate fibrous concrete (TECAFC) is a new concrete type and an emerging research area in material engineering. The casting method of TECAFC includes the two essential phases as follows. First, ECA and fibres are filled into the empty cylindrical mould to develop a natural skeleton. Second, the grout comprising cement, sand and MWCNT, are injected into the developed skeleton to fill voids. In this research, eight mixtures were prepared with 0.1 and 0.2% of MWCNT, 2.5% dosage of SF and three different layers of GFM inserted between the two layers of concrete. These eight mixtures were divided into two series of three mixtures each, in addition to two reference mixtures that include no SF or GFM. The first series of mixtures was comprised of 0.1% of MWCNT and 2.5% of SF and one, two and three layers of GFM insertion. The second series was the same as the first series and the dosage of MWCNT was taken as 0.2%. All cylindrical specimens were tested under drop mass impact as per the suggestions made by the ACI Committee 544. The test results showed that incorporating steel fibres and GFM improved the cracking and failure impact resistance by more than 270 and 1100%, respectively, and increased the impact ductility index by more than 220%, significantly contributing to steel fibres.

Download Full-text

Mechanical properties and fibre density of steel fibrereinforced self-compacting concrete slabs by DIA and XCT approaches

Journal of Civil Engineering and Management ◽

10.3846/13923730.2016.1217922 ◽

2017 ◽

Vol 23 (5) ◽

pp. 604-612 ◽

Cited By ~ 5

Author(s):

Tomasz PONIKIEWSKI ◽

Jacek KATZER

Keyword(s):

Mechanical Properties ◽

Fibre Length ◽

Research Programme ◽

Experimental Tests ◽

Flexural Behaviour ◽

Mixture Flow ◽

Steel Fibres ◽

Flexural Tensile Strength ◽

Oriented Parallel ◽

Concrete Casting

The aim of the research programme was to investigate flexural behaviour of steel fibre reinforced self-compacting concrete (SFRSCC). The specimens were in a form of slabs reinforced with steel fibres (of three lengths and two shapes) by volumes of 1.0% and 1.5%. Two methods of casting slabs were examined. The experimental tests performed on 80 specimens cut from slabs (1.2×1.2×0.15 m) involved tests of mechanical properties, digital image analysis (DIA), and X-ray computed tomography (XCT) procedures. Determination of distribution of fibres by DIA and XCT was required to assess relationships between mechanical properties and the casting methods. The tests were conducted according to RILEM TC 162-TDF (2002) and EN 14651:2005+A1:2007(E) recommendations. The study confirmed the technological problems associated with uneven distribution of steel fibres in SCC matrix. Based on the performed analysis, the flexural tensile strength of SFRSCC cannot be described with the formulas used for SFRC. Fibres are generally oriented parallel to the direction of concrete mixture flow in a mould. This phenomenon is influenced by fibre length and the location of concrete casting point (CCP). It was also demonstrated that the flexural behaviour of tested elements is influenced by CCP.

Download Full-text

Investigating Flexural Behaviour of Prestressed Concrete Girders Cast by Fibre-Reinforced Concrete

Advances in Civil Engineering ◽

10.1155/2019/1459314 ◽

2019 ◽

Vol 2019 ◽

pp. 1-11 ◽

Cited By ~ 1

Author(s):

Muhammad U. Rashid ◽

Liaqat A. Qureshi ◽

Muhammad F. Tahir

Keyword(s):

Reinforced Concrete ◽

Construction Industry ◽

Prestressed Concrete ◽

Volume Fraction ◽

Small Scale ◽

Fibre Reinforced Concrete ◽

Flexural Behaviour ◽

Steel Fibres ◽

Concrete Girders ◽

Prestressed Concrete Girders

The main objective of this research was to investigate the effect of adding polypropylene and steel fibres on flexural behaviour of prestressed concrete girders. Although the construction industry is frequently using prestressed concrete to increase the load-carrying capacity of structures, it can be further enhanced by using fibres. In this paper, experimental work was carried out to encourage the construction industry in utilizing fibres in prestressed concrete members to improve the mechanical properties of these members. As past investigations on fibre-reinforced prestressed beams were limited, the present work was done on small-scale fibre-reinforced I-shaped prestressed concrete girders. Six small-scale prestressed concrete girders were cast comprising a control girder, a hybrid girder, two girders with varying percentages of steel fibres, and two girders with varying percentages of polypropylene fibres. These girders were tested by centre point loading up to failure. It was concluded that, by the addition of small volume fraction of fibres, not only the ductility but also the tensile strength and flexural strength of FRC girders could be improved. It also altered the failure pattern positively by enhancing large strains in concrete and steel. Steel fibre-reinforced concrete showed higher energy absorption and deflection at ultimate loads in comparison to other specimens.

Download Full-text

An experimental study on flexural behaviour of large-scale concrete beams incorporating crumb rubber and steel fibres

Engineering Structures ◽

10.1016/j.engstruct.2017.05.018 ◽

2017 ◽

Vol 145 ◽

pp. 97-108 ◽

Cited By ~ 19

Author(s):

Mohamed K. Ismail ◽

Assem A.A. Hassan

Keyword(s):

Experimental Study ◽

Large Scale ◽

Concrete Beams ◽

Crumb Rubber ◽

Flexural Behaviour ◽

Steel Fibres

Download Full-text

Flexural behaviour of reinforced and prestressed solite structural lightweight concrete beams

Building Science ◽

10.1016/0007-3628(75)90007-9 ◽

1975 ◽

Vol 10 (1) ◽

pp. 43-56 ◽

Cited By ~ 3

Author(s):

R.N. Swamy ◽

A.B. Ibrahim

Keyword(s):

Lightweight Concrete ◽

Concrete Beams ◽

Flexural Behaviour

Download Full-text

Effect of geo-grid and steel fibres on flexural behaviour of reinforced concrete beams

Materials Today Proceedings ◽

10.1016/j.matpr.2021.05.452 ◽

2021 ◽

Author(s):

Nishanthi P ◽

Vidjeapriya R ◽

Sivaram S ◽

Sathish K ◽

Bharath K ◽

...

Keyword(s):

Reinforced Concrete ◽

Concrete Beams ◽

Reinforced Concrete Beams ◽

Flexural Behaviour ◽

Steel Fibres

Download Full-text

Structural Performance of Steel Fibre Reinforced Lightweight Concrete Frames Subjected to Lateral Load

International Journal of Innovative Technology and Exploring Engineering - Special Issue ◽

10.35940/ijitee.b1010.1292s219 ◽

2019 ◽

Vol 9 (2S2) ◽

pp. 34-37 ◽

Cited By ~ 2

Keyword(s):

Coarse Aggregate ◽

Lightweight Concrete ◽

Low Density ◽

Concrete Frames ◽

Structural Behaviour ◽

Displacement Ductility ◽

Steel Fibres ◽

Rc Frames ◽

Lateral Forces ◽

Volcanic Source

Masonry infilled Reinforced Concrete (RC) framed structure is the utmost common kind of building in which, RC frames contribute in resisting lateral forces. Due to heavy mass and rigid construction, the RC framed buildings performs unfortunate under lateral forces. Practice of Lightweight concrete (LWC) is superlative because the dead load of concrete is massive. Low density materials are chosen in LWC, reduces the mass of the building thus decreasing the influence of lateral forces. However, LWC having a lesser modulus of elasticity has a more rapidly develops the cracks in the RC members. In this investigation, pumice is a naturally available material of volcanic source, has low density, which creates it ideal for production of LWC, likewise steel fibres are employed as an additive to enhance the energy absorption ability and to reduce the possibility of development of the cracks. In the present paper the structural behaviour of Lightweight RC framed structures realized by using steel fibres and subjected to lateral forces, In this study, four RC frames viz., F1-NWC (Control), F2- NWCF (with 1% Vf of steel fibres), F3-LWC (with 20% substitute of coarse aggregate instead of pumice aggregate) and F4-LWCF (with 20% substitute of coarse aggregate instead of pumice aggregate and 1% Vf of steel fibres) were casted and tested under in-plane horizontal loading, which are designed according to Indian Standard (IS) code IS 456 (2000). It was observed that the behaviour of F4-LWCF significantly better in comparison to other frames in various parameters such as load carrying capacity, displacement, ductility, stiffness and energy dissipation.

Download Full-text