scholarly journals Mechanical flexural properties of concrete with melt-extract stainless steel fibres

2021 ◽  
Vol 72 (12) ◽  
pp. 1155-1164
Author(s):  
Stjepan Lakusic

An experimental study is performed to evaluate the effect of melt-extract stainless steel fibres on mechanical and flexural properties of concrete. A total of seventy-two specimens are used to determine an optimum fibre dosage and mechanical properties of plain and steel fibre reinforced concrete. Twelve full-scale beam specimens are then exposed to four-point bending tests. The effect of melt-extract stainless steel fibres on flexural behaviour of beams is quantified in this testing. A beam specimen is exposed to four-point bending, after being subjected to 15000 cycles of fatigue load. Pre- and post-fatigue flexural properties of beams with melt-extract steel fibres are compared and discussed.

2021 ◽  
Vol 15 (1) ◽  
pp. 81-92
Author(s):  
Constantinos B. Demakos ◽  
Constantinos C. Repapis ◽  
Dimitros P. Drivas

Aims: The aim of this paper is to investigate the influence of the volume fraction of fibres, the depth of the beam and the shear span-to-depth ratio on the shear strength of steel fibre reinforced concrete beams. Background: Concrete is a material widely used in structures, as it has high compressive strength and stiffness with low cost manufacturing. However, it presents low tensile strength and ductility. Therefore, through years various materials have been embedded inside it to improve its properties, one of which is steel fibres. Steel fibre reinforced concrete presents improved flexural, tensile, shear and torsional strength and post-cracking ductility. Objective: A better understanding of the shear performance of SFRC could lead to improved behaviour and higher safety of structures subject to high shear forces. Therefore, the influence of steel fibres on shear strength of reinforced concrete beams without transverse reinforcement is experimentally investigated. Methods: Eighteen concrete beams were constructed for this purpose and tested under monotonic four-point bending, six of which were made of plain concrete and twelve of SFRC. Two different aspect ratios of beams, steel fibres volume fractions and shear span-to-depth ratios were selected. Results: During the experimental tests, the ultimate loading, deformation at the mid-span, propagation of cracks and failure mode were detected. From the tests, it was shown that SFRC beams with high volume fractions of fibres exhibited an increased shear capacity. Conclusion: The addition of steel fibres resulted in a slight increase of the compressive strength and a significant increase in the tensile strength of concrete and shear resistance capacity of the beam. Moreover, these beams exhibit a more ductile behaviour. Empirical relations predicting the shear strength capacity of fibre reinforced concrete beams were revised and applied successfully to verify the experimental results obtained in this study.


2017 ◽  
Vol 23 (6) ◽  
pp. 806-813 ◽  
Author(s):  
Inmaculada MARTÍNEZ-PÉREZ ◽  
Juozas VALIVONIS ◽  
Remigijus ŠALNA ◽  
Alfonso COBO-ESCAMILLA

The building of structures from steel fibre reinforced concrete (SFRC) in the external and conventional rein­forced concrete (RC) in the internal layer represents an economical alternative of structures effectively using SFRC. The paper presents test results of flexural behaviour of layered beams with SFRC external layers and RC internal layer. The behaviour of these beams is compared to test results of SFRC and conventional RC beams. The test results show, that the flexural load capacity for all series of beams is nearly similar, but the deflections of layered beams are less comparing to monolithic ones. It also been shown that the equations indicated in the Eurocode 2 can be used to design the flexural reinforcement in layered SFRC beams.


2019 ◽  
Vol 53 (28-30) ◽  
pp. 4137-4148 ◽  
Author(s):  
TA Sebaey ◽  
Ahmed Wagih

Hybrid composite laminates are currently receiving researchers’ attention due to their specific advantages in designing laminates with improved specific strength and stiffness. One of the main disadvantages of polymeric laminated composites is their high sensitivity to notches, which cannot be avoided in design. This paper presents a comparison between two common hybridization techniques, namely sandwich and intra-ply hybridization. The study adopts experimental observations to investigate the influence of hybridization method on the flexural properties of notched carbon–aramid hybrid laminates. After four-point bending tests, the results show that the damage nature in both laminates is different. A catastrophic damage is observed for intra-ply hybrid laminates, while sandwich laminates show progressive damage. In terms of the strength, sandwich specimens show 1.3 times higher specific strength, compared to intra-ply specimens. Moreover, the bottom layers of the laminate manufactured in the sandwich fashion show minimal damage due to the high capability of the aramid/epoxy core to absorb the energy in deformation and concentrate the damage at the top layers (the compression side).


2010 ◽  
Vol 168-170 ◽  
pp. 1325-1329
Author(s):  
Ye Ran Zhu ◽  
Jun Cai ◽  
Dong Wang ◽  
Guo Hong Huang

This paper investigates the mechanical properties (compressive strength, splitting tensile strength and flexural toughness) of polypropylene fiber reinforced self-compacting concrete (PFRSCC). The effect of the incorporation of polypropylene fiber on the mechanical properties of PFRSCC is determined. Four point bending tests on beam specimens were performed to evaluate the flexural properties of PFRSCC. Test results indicate that flexural toughness and ductility are remarkably improved by the addition of polypropylene fiber.


2014 ◽  
Vol 580-583 ◽  
pp. 2213-2219 ◽  
Author(s):  
Lin Liao ◽  
Sergio Cavalaro ◽  
Albert de la Fuente ◽  
Antonio Aguado

Many researches have been conducted in past decades for promoting the application of steel fibre reinforced concrete (SFRC), either conventional or self-compacting. However, the differences of post-crack behaviour and the properties of these two types of concrete remains unclear. The objective of this paper is to analyse such differences in terms of flexural behaviour, fibre orientation and contribution as well as the fibre content. For that, an extensive experimental campaign was carried out. In total 3 mixes of self-compacting and 3 mixes with traditional concrete were produced with the nominal fibre contents of 30kg/m3, 45kg/m3 and 60kg/m3. In each series, specimens were produces and characterized by three point bending test (code EN 14651) and inductive test. The results illustrate how fibre orientation and distribution justify the differences in the mechanical behaviour of the materials and the scatter of the bending test results.


Author(s):  
Kunio Hasegawa ◽  
Katsumasa Miyazaki ◽  
Koichi Saito ◽  
Bostjan Bezensek

Multiple flaws such as stress corrosion cracks are frequently detected in the same welded lines in pipes. If multiple discrete flaws are in close proximity to one another, alignment rules are used to determine whether the flaws should be treated as non-aligned or as coplanar. Alignment rules are provided in fitness-for-service codes, such as ASME, JSME, API 579, BS 7910, etc. However, the criteria of the alignment rules are different among these codes. This paper briefly introduces these flaw alignment rules, and four-point bending tests performed on stainless steel pipes with two non-aligned flaws. The experimental plastic collapse stresses are determined from the collapse loads and compared with collapse stresses calculated from the limit load criteria. The limit loads are obtained for single non-aligned or aligned coplanar flaws in accordance with the alignment rules. On this basis, the conservatism of the alignment rules in the above codes is assessed.


2001 ◽  
Vol 10 (1) ◽  
pp. 096369350101000 ◽  
Author(s):  
K. Fujihara ◽  
Zheng-Ming Huang ◽  
S. Ramakrishna ◽  
K. Satkunanantham ◽  
H. Hamada

In this study, a novel fabrication method using braiding technique was applied to fabricate carbon/PEEK composite bone plates. Four-point bending tests of the composite plates were carried out to compare with the conventional stainless-steel bone plate. The braided composite bone plates with considered braiding angles displayed a maximum bending moment in the range of 38.2 ∼ 44.0 % and bending stiffness in the range of 26.6 ∼ 30.2 % of those of a stainless-steel plate. The bending properties of braided composite plates are comparable with those of the polymer composite bone plates reported in the literature. The potential of braided carbon/PEEK composite material for bone fracture fixation applications is indicated.


2016 ◽  
Vol 126 ◽  
pp. 253-262 ◽  
Author(s):  
Bensaid Boulekbache ◽  
Mostefa Hamrat ◽  
Mohamed Chemrouk ◽  
Sofiane Amziane

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