The Experimental Testing of the Tensile Strength of the Steel Fibre Reinforced Cement Matrix

2015 ◽  
Vol 824 ◽  
pp. 197-200
Author(s):  
Jan Machovec ◽  
Filip Vogel ◽  
Petr Konvalinka

This article is focused on state of knowledge about experimental testing of uniaxial tension strength of specimens from cement-based composites. We searched for various types of experimental testing of tensile strength, shapes of specimens or type of reinforcement. There is our own experimental program at the end of this article. Our aim is to find the best way to test steel fibre reinforced cement matrix for textile reinforced concrete in oneaxial tension. Textile reinforced concrete has many advantages (e.g.: no covering layer, higher ductility) and may be used instead of common steel reinforced concrete or as a method to repair old structures (e.g.: to bind columns).

2016 ◽  
Vol 827 ◽  
pp. 271-274
Author(s):  
Filip Vogel ◽  
Jan Machovec ◽  
Petr Konvalinka

This article deals with experimental testing of the textile reinforced concrete samples. The main topic of this article is determination ultimate tensile strength of the textile reinforced concrete. The testing samples were in form “dogbone” for good fixing in testing machine. There are 12 samples totally in experimental program. One type cement matrix and three types (difference in their weight 125 g/m2, 275 g/m2 and 500 g/m2) glass textile reinforcement were used for the production of samples. The textile reinforcement is made of alkali-resistant glass fibres. Three samples were made of cement matrix and nine samples were made of cement matrix reinforced textile reinforcement (three of each type of reinforcement). The samples were tested in special attachment in one-axial tensile. Experimental tests were controlled by speed of rate of deformation (0.0005 m/min). The textile reinforcement has very good influence to behaviour of the textile reinforced concrete in tensile stress.


2015 ◽  
Vol 824 ◽  
pp. 155-159 ◽  
Author(s):  
Filip Vogel ◽  
Ondřej Holčapek ◽  
Petr Konvalinka

This article deals with cement matrix for the textile reinforced concrete. It is necessary to know maximum of the mechanical properties of cement matrix for using textile reinforced concrete. The main topic of this article is to determine stress-strain diagrams at various age of the cement matrix. The compressive strength of the cement matrix was determined by using cube specimens (100 x 100 x 100 mm). The cement matrix, steel fibre reinforced cement matrix and ordinary concrete C 30/37 were tested at age 12 and 18 hours and 1, 7, 28 and 45 days. Cubes were tested in one-axial press. Loading of cubes was controlled by increase of deformation. Speed of loading was 0.008 mm/s. Time, load force and deformation were recorded for determination stress strain diagrams. The results of the experimental program and stress-strain diagrams were compared with each other in conclusion of this article.


2014 ◽  
Vol 982 ◽  
pp. 59-62 ◽  
Author(s):  
Filip Vogel

This article discusses about the textile reinforced concrete. The textile reinforced concrete is a new material with great possibilities for modern construction. The textile reinforced concrete consists of cement matrix and textile reinforcement of high strength fibers. This combination of cement matrix and textile reinforcement is an innovative combination of materials for use in the construction. The main advantage of the textile reinforced concrete is a high tensile strength and ductile behavior. The textile reinforced concrete is corrosion resistant. With these mechanical properties can be used textile reinforced concrete in modern construction.


2016 ◽  
Vol 827 ◽  
pp. 227-230
Author(s):  
Ondřej Holčapek

Presented contribution deals with using textile reinforced concrete containing newly invented high strength cement matrix for strengthening concrete structures. The issue of old concrete ́s surface interaction with newly applied slim layer of textile reinforced concrete is investigated and verified by bending test. Water to binder ration under 0.3, maximum size of used silica sand 1.2 mm, and compressive strength over 100 MPa characterize used fine grain cement matrix. Over 12 months old beams with dimension 100 x 100 x 400 mm made from ordinary concrete were used for strengthening during performed experimental program. Strengthening took place on bending side. Different number (1, 3 and 5) of textile fabrics made from alkali-resistant glass (surface density 275 g/m2) was applied into slim layer of cement composite. Increasing number of used fabrics leads to different failure mode due shearing force action.


2014 ◽  
Vol 1054 ◽  
pp. 99-103 ◽  
Author(s):  
Filip Vogel ◽  
Ondřej Holčapek ◽  
Petr Konvalinka

This article deals with cement matrix for textile reinforced concrete. The main topic of this article is study of the development of the mechanical properties of the cement matrix. It was studied cube compressive strength and tensile strength in bending. The cement matrix has a similar composition as high performance concrete. Commonly used concrete was made to compare with the cement matrix. The cubes and prisms were made for the experimental program. The mechanical properties were studied at the age 12, 15, 18 and 21 hours and 1, 2, 3, 7, 14, 21 and 28 days.


2018 ◽  
Vol 58 (4) ◽  
pp. 245
Author(s):  
Jan Machovec ◽  
Pavel Reiterman

This article deals with the long-term durability of a relatively new composite – textile reinforced concrete (TRC). The studied composite material introduces a modern and favourite solution in contemporary architecture and structural engineering. It could also be used in renovation and monument restoration due to its high utility properties. The experimental program was focused on the determination of the resistance of the TRC in an aggressive environment using durability accelerated tests. The high performance concrete (HPC), which we used in our study, exhibited a compressive strength exceeding 100MPa after 28 days. Specimens were subjected to a 10% solution of H2SO4, 10% solution of NaOH, and freeze-thaw cycling respectively. All these environments can occur in real conditions in the TRC practical utilization. The testing was carried out on “dog-bone” shaped specimens, specially designed for the tensile strength measurement. Studied TRC specimens were reinforced by textiles of three different square weight that were applied in one or two layers, which led to the expected increase of tensile strength The freeze-thaw cycling had the biggest influence on the tensile properties, because it causes micro-cracks formation. The specimens exposed to the chemically aggressive environment deteriorated mostly on the surface, because of the high density of the concrete and generally low penetration of the media used. The resistance of the studied TRC to the aggressive environment increased with the applied reinforcement rate. The performed experimental programme highlighted the necessity of including the durability properties in the design of structural elements.


2015 ◽  
Vol 824 ◽  
pp. 161-165
Author(s):  
Ondřej Holčapek

This contribution deals with interesting and progressive curing method applied to fresh concrete matrix for textile reinforced concrete production. The application of high pressure 0.3 MPa and temperature 130 °C in 100 % humidity environment for 4 hours was performed. Cement matrix and steel fibers reinforced cement matrix has been investigated. The goal of this research is to quantified compressive strength, flexure strength, bulk density and dynamic modulus of elasticity of both mixtures. These parameters were investigated after hydrothermal curing process at the ages 6, 12, 15, 18, 21 and 24 hour after first contact of water with cement. All parameters were investigated on specimens 40 x 40 x 160 mm3 and the destructive tests were controlled by increase of deformation. Special curing condition led to an increase of the compressive strength by more than 10 % in case of cement matrix, and by more than 40 % in case of fiber reinforced cement matrix.


2021 ◽  
Vol 301 ◽  
pp. 124300
Author(s):  
Dimas Alan Strauss Rambo ◽  
Caroline Umbinger de Oliveira ◽  
Renan Pícolo Salvador ◽  
Romildo Dias Toledo Filho ◽  
Otávio da Fonseca Martins Gomes ◽  
...  

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2127
Author(s):  
Richard Fürst ◽  
Eliška Fürst ◽  
Tomáš Vlach ◽  
Jakub Řepka ◽  
Marek Pokorný ◽  
...  

Textile-reinforced concrete (TRC) is a material consisting of high-performance concrete (HPC) and tensile reinforcement comprised of carbon roving with epoxy resin matrix. However, the problem of low epoxy resin resistance at higher temperatures persists. In this work, an alternative to the epoxy resin matrix, a non-combustible cement suspension (cement milk) which has proven stability at elevated temperatures, was evaluated. In the first part of the work, microscopic research was carried out to determine the distribution of particle sizes in the cement suspension. Subsequently, five series of plate samples differing in the type of cement and the method of textile reinforcement saturation were designed and prepared. Mechanical experiments (four-point bending tests) were carried out to verify the properties of each sample type. It was found that the highest efficiency of carbon roving saturation was achieved by using finer ground cement (CEM 52.5) and the pressure saturation method. Moreover, this solution also exhibited the best results in the four-point bending test. Finally, the use of CEM 52.5 in the cement matrix appears to be a feasible variant for TRC constructions that could overcome problems with its low temperature resistance.


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.


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