Study of the Strength Development of the Cement Matrix for Textile Reinforced Concrete

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.

2014 ◽  
Vol 982 ◽  
pp. 119-124 ◽  
Author(s):  
Tomáš Vavřiník ◽  
Jan Zatloukal

This paper describes influence of different mechanical properties to the concrete penetration resistance. The resistance is evaluated on the basis of the presented experimental program. In the experiment, non-deformable ogive-nose projectiles with diameter of 7.92 mm and mass of 8 g with impact velocity of about 700 m/s were hitting center of the specimens. Determination of the concrete penetration resistance was than based on projectile residual velocity obtained from high-speed camera record. The specimens were made from high strength concrete, steel fiber-reinforced concrete, ultra-high performance concrete and ultra-high performance fiber-reinforced concrete with different fiber content. The concrete penetration resistance was evaluated on total 32 specimens. Influence of mechanical properties, addition of coarse aggregate and steel fibers were discussed. Mechanical properties of the tested materials were investigated on total 125 specimens. Data from the measurements were used for creation of new RHT concrete models in Autodyn. In order to confirm experiment's setup and results, numerical analysis was performed in Autodyn. Results of the numerical simulations were compared to the experimental program.


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.


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.


Buildings ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 68
Author(s):  
Egodawaththa Ralalage Kanishka Chandrathilaka ◽  
Shanaka Kristombu Baduge ◽  
Priyan Mendis ◽  
Petikirige Sadeep Madhushan Thilakarathna

Textile Reinforced Concrete (TRC) is a prefabricated novel lightweight high-performance composite material that can be used as a load-bearing or non-load-bearing component of prefabricated buildings. Making TRC with Ultra-High-Strength Concrete (UHSC) (≥100 MPa) can be considered as a potential improvement method to further enhance its properties. This paper investigated the performance of Ultra-High-Strength Textile Reinforced Concrete (UHSTRC) under flexural loading. A detailed experimental program was conducted to investigate the behavior of UHSC on TRC. In the experimental program, a sudden drop in load was observed when the first crack appeared in the UHSTRC. A detailed analytical program was developed to describe and understand such behavior of UHSTRC found in experiments. The analytical program was found to be in good agreement with the experimental results and it was used to carry out an extensive parametric study covering the effects of the number of textile layers, textile material, textile mesh density, and UHSTRC thickness on the performance of UHSTRC. Using a high number of textile layers in thin UHSTRC was found to be more effective than using high-thickness UHSTRC. The high modulus textile layers effectively increase the performance of UHSTRC.


Author(s):  
Ester Gimenez-Carbo ◽  
Raquel Torres ◽  
Pedro Serna

The overall objective of the work is the development of ultra high performance fiber reinforced concrete (UHPFRC) dosages that can be used for shotcrete. In this study, a number of UHPFRC mixtures with different amount of admixtures (plasticizers and accelerating) and different mixing time were tested, to increase either the rate of stiffening or setting of the concrete or the rate of hardening and early-strength development. Workability, consistency and mechanical properties of UHPFRC including compressive and flexural strengths at different ages were assessed. Results showed mixtures than begin their first setting in less than 1 minute, with very good mechanical properties in 24 hours, and without reducing the compressive strength at 28 days. From the results obtained, various uses of these mixtures are proposed taking into account, the new context of the Construction field, with the appearance of new placing concrete techniques.


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.


Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5098
Author(s):  
Anna L. Mina ◽  
Konstantinos G. Trezos ◽  
Michael F. Petrou

This study describes an extensive experimental investigation of various mechanical properties of Ultra-High-Performance Fibre-Reinforced Concrete (UHPFRC). The scope is to achieve high strength and ductile behaviour, hence providing optimal resistance to projectile impact. Eight different mixtures were produced and tested, three mixtures of Ultra-High-Performance Concrete (UHPC) and five mixtures of UHPFRC, by changing the amount and length of the steel fibres, the quantity of the superplasticizer, and the water to binder (w/b) ratio. Full stress–strain curves from compression, direct tension, and flexural tests were obtained from one batch of each mixture to examine the influence of the above parameters on the mechanical properties. The Poisson’s ratio and modulus of elasticity in compression and direct tension were measured. Additionally, a factor was determined to convert the cubic strength to cylindrical. Based on the test results, the mixture with high volume (6%) and a combination of two lengths of steel fibres (3% each), water to binder ratio of 0.16% and 6.1% of superplasticizer to binder ratio exhibited the highest strength and presented great deformability in the plastic region. A numerical simulation developed using ABAQUS was capable of capturing very well the experimental three-point bending response of the UHPFRC best-performed mixture.


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.


2018 ◽  
Vol 165 ◽  
pp. 22010
Author(s):  
Nesrine Khodja ◽  
Hadda Hadjab

This paper presents an experimental study on the performance of concrete, subjected to high temperatures. Investigation was carried out by using two mixtures: an Ordinary Concrete (OC) and High Performance Concrete (HPC) with 10% of Silica Fume (SF) replaced of cement weight and 1,5% of super plasticizer, the water-binder (w/b) ratio used was 0,5 and 0,32 respectively. The produced concrete specimens are heated at a rate of 7 °C/min up to different temperatures (150, 300, 450, 600 and 900°C). In order to ensure a uniform temperature through the specimen, the temperature is held constant at the temperature stage for one hour before cooling. Mechanical properties at ambient temperature and residual mechanical properties after heating have already been determined. We examined also the effect of high temperature on the aggregate-cement paste interface and aggregate microstructure of the concrete specimens by scanning electron microscopy (SEM) method to reveal changes occurred after the cycle of heatingcooling. The results revealed that relative strength of the concrete specimens decreased as the exposure temperature increased and reaches about a quarter of its initial strength at 900°C. Moreover SEM examinations showed that, increasing temperature caused weakening of the adherence of aggregate and cement matrix by the appearance of cracks and micro cracks.


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