High Strength Concrete Matrix for Textile Reinforced Concrete Production in Special Curing Conditions

2015 ◽  
Vol 824 ◽  
pp. 161-165
Author(s):  
Ondřej Holčapek
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
High Strength ◽  
Cement Matrix ◽  
Textile Reinforced Concrete ◽  
Curing Conditions ◽  
Concrete Production ◽  
Reinforced Cement ◽  
Curing Method ◽  
Concrete Matrix

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.

scholarly journals ANALYSIS OF MECHANICAL PROPERTIES OF HYDROTHERMALLY CURED HIGH STRENGTH CEMENT MATRIX FOR TEXTILE REINFORCED CONCRETE

2015 ◽  
Vol 55 (5) ◽  
pp. 313 ◽  
Author(s):  
Ondřej Holčapek ◽  
Filip Vogel ◽  
Petr Konvalinka
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Flexural Strength ◽  
High Strength ◽  
Positive Influence ◽  
Cement Matrix ◽  
Textile Reinforced Concrete ◽  
Curing Conditions ◽  
Hydrothermal Curing ◽  
Concrete Production

The main objective of this article is to describe the influence of hydrothermal curing conditions in an autoclave device (different pressure and temperature), which took place at various ages of a fresh mixture (cement matrix – CM, and fibre-reinforced cement matrix – FRCM), on textile reinforced concrete production. The positive influence of autoclaving has been evaluated through the results of physical and mechanical testing – compressive strength, flexural strength, bulk density and dynamic modulus of elasticity, which have been measured on specimens with the following dimensions: 40×40×160mm<sup>3</sup>. In addition, it has been found that increasing the pressure and temperature resulted in higher values of measured characteristics. The results indicate that the most suitable surrounding conditions are 0.6MPa, and 165 °C at the age of 21 hours; the final compressive strength of cement matrix is 134.3MPa and its flexural strength is 25.9MPa (standard cured samples achieve 114.6MPa and 15.7MPa). Hydrothermal curing is even more effective for cement matrix reinforced by steel fibres (for example, the compressive strength can reach 177.5MPa, while laboratory-cured samples achieve a compressive strength of 108.5MPa).

Production and Use of the Textile Reinforced Concrete

2014 ◽  
Vol 982 ◽  
pp. 59-62 ◽  
Author(s):  
Filip Vogel
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Reinforced Concrete ◽  
High Strength ◽  
Cement Matrix ◽  
High Tensile Strength ◽  
Textile Reinforced Concrete ◽  
Corrosion Resistant ◽  
New Material ◽  
Ductile Behavior

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.

Investigation of Bending Capacity of Concrete Elements Strengthened by Textile Reinforced Concrete

2016 ◽  
Vol 827 ◽  
pp. 227-230
Author(s):  
Ondřej Holčapek
Keyword(s):  
Reinforced Concrete ◽  
High Strength ◽  
Maximum Size ◽  
Cement Composite ◽  
Silica Sand ◽  
Bending Test ◽  
Experimental Program ◽  
Cement Matrix ◽  
Textile Reinforced Concrete ◽  
Bending Capacity

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.

Comparison of Stress-Strain Diagrams in Different Age of the Cement Matrix for Textile Reinforced Concrete

2015 ◽  
Vol 824 ◽  
pp. 155-159 ◽  
Author(s):  
Filip Vogel ◽  
Ondřej Holčapek ◽  
Petr Konvalinka
Keyword(s):  
Reinforced Concrete ◽  
Load Force ◽  
Experimental Program ◽  
Cement Matrix ◽  
Textile Reinforced Concrete ◽  
Stress Strain ◽  
Ordinary Concrete ◽  
Deformation Speed ◽  
Reinforced Cement ◽  
C 30

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.

Bond Characteristics of TRC Slabs Cured in Autoclave

2016 ◽  
Vol 722 ◽  
pp. 305-310 ◽  
Author(s):  
Ondřej Holčapek
Keyword(s):  
Experimental Investigation ◽  
Compressive Strength ◽  
Bending Test ◽  
Cement Matrix ◽  
Textile Reinforced Concrete ◽  
Aesthetic Quality ◽  
Production Program ◽  
Curing Conditions ◽  
Real Practice ◽  
Bond Characteristics

Textile reinforced concrete (TRC) found its application in real practice and several producers and companies included TRC ́s elements into their production program. The most popular and widespread are slim façade panels with high aesthetic quality and excellent durability. Curing conditions influence the final properties, which is important especially in precast production where special devices can be used. This paper deals with experimental investigation of bond characteristics of slabs made from TRC hydrothermally cured in autoclave device and reference slabs cured in laboratory conditions for 28 days. Dimension of TRC slabs was 230 x 100 x 20 mm. Compressive strength 100 MPa characterizes used cement matrix (laboratory cured after 28 days). Basalt and AR-glass fabrics with different properties were used as reinforcement. Three-points bending test with clear span of supports 200 mm evaluated maximum bond capacity and load-deflection diagrams described character of failure and ductility.

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
Keyword(s):  
Tensile Strength ◽  
Reinforced Concrete ◽  
Steel Fibre ◽  
Experimental Testing ◽  
Experimental Program ◽  
Cement Matrix ◽  
Textile Reinforced Concrete ◽  
Steel Reinforced Concrete ◽  
Test Steel ◽  
Reinforced Cement

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).

Bond Properties of Concrete Beams Strengthened by AR-Glass Textile and Basalt Textile Reinforced Concrete

2016 ◽  
Vol 825 ◽  
pp. 7-10 ◽  
Author(s):  
Ondřej Holčapek ◽  
Filip Vogel
Keyword(s):  
Reinforced Concrete ◽  
Surface Density ◽  
Concrete Beams ◽  
High Strength ◽  
Bending Test ◽  
Cement Matrix ◽  
Textile Reinforced Concrete ◽  
Fine Grain ◽  
Fabric Surface ◽  
Textile Fabric

This paper deals with advanced application of textile reinforced concrete for strengthening and stabilization of existing load-bearing structure elements. Slim layer of fine grain concrete with compressive strength over 100 MPa was applied on one year old concrete beams with dimension 100 x 100 x 400 mm. Different number of layers of two types of textile fabrics was applied into concrete layer. One textile fabric was made from alkali-resistant glass fabric with surface density 585 g/m2 and the second was made from basalt fabric with surface density 260 g/m2. One layer of basalt textile fabric (surface density 120 g/m2) was applied on the top of strengthening layer to prevent shrinkage cracks of high strength cement matrix. Evaluation of destructive four points bending test of strengthened and reference specimens provided the efficiency of performed strengthening solution. Continual load and deflection measurement during bending test enables to create load-deflection diagram, where the action of textile can be observed.

scholarly journals Use of Cement Suspension as an Alternative Matrix Material for Textile-Reinforced Concrete

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2127
Author(s):  
Richard Fürst ◽  
Eliška Fürst ◽  
Tomáš Vlach ◽  
Jakub Řepka ◽  
Marek Pokorný ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Epoxy Resin ◽  
High Performance Concrete ◽  
Bending Test ◽  
Resin Matrix ◽  
Cement Matrix ◽  
Sample Type ◽  
Textile Reinforced Concrete ◽  
Epoxy Resin Matrix ◽  
Four Point Bending

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.

scholarly journals Flow Mechanism and Strength Characteristics of Textile Reinforced Concrete Mixed with Colloidal Nano-SiO2

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Ping Xu ◽  
Rui Shi ◽  
Chao Wang ◽  
Yuhao Cui ◽  
Minxia Zhang
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Flexural Strength ◽  
Silica Fume ◽  
Inhibitory Effect ◽  
Equal Mass ◽  
Textile Reinforced Concrete ◽  
Nano Sio2 ◽  
Four Point Bending ◽  
Concrete Filling

In order to develop textile reinforced concrete (TRC) with good flowability and strength, colloidal nano-SiO2 (CNS) is adopted to improve the performance of TRC. The flowability, compressive strength, flexural strength, and four-point bending tests of TRC matrix with CNS are carried out, and the changes of internal micromorphological characteristics of TRC matrix are analyzed by combining with scanning electron microscopy. The results show that the CNS has an inhibitory effect on the flowability of TRC matrix, and the greater the amount of admixture is, the smaller the slump expansion of TRC matrix is. The compressive strength and flexural strength of TRC matrix show a trend of increasing and then decreasing as the amount of CNS increases, and the compressive strength reaches the maximum at each age (7 d, 14 d, 28 d) when CNS and silica fume replace 5% cement by 1 : 4 equal mass. The flexural strength reaches the maximum at each age (7 d, 14 d, 28 d) when 5% cement is replaced by CNS and silica fume with 3 : 7 equal mass. The flexural strength increases with the increase of CNS admixture. It is found by electron microscope scanning that the incorporation of CNS consumes more Ca(OH)2, refines the Ca(OH)2 crystal size, and generates more C-S-H gels. These C-S-H gels are distributed in a net-like pattern inside the concrete, filling the internal pores, effectively densifying the interfacial transition zone between the cementitious material and the aggregates, and optimizing the internal structure.

scholarly journals Artificial Neural Network Estimation of the Effect of Varying Curing Conditions and Cement Type on Hardened Concrete Properties

Buildings ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 10 ◽  
Author(s):  
Gökhan Kaplan ◽  
Hasbi Yaprak ◽  
Selçuk Memiş ◽  
Abdoslam Alnkaa
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Limestone Powder ◽  
Mineral Admixtures ◽  
Hardened Concrete ◽  
Slag Cement ◽  
Curing Conditions ◽  
Concrete Properties ◽  
Concrete Production ◽  
Artificial Neural

The use of mineral admixtures and industrial waste as a replacement for Portland cement is recognized widely for its energy efficiency along with reduced CO2 emissions. The use of materials such as fly ash, blast-furnace slag or limestone powder in concrete production makes this process a sustainable one. This study explored a number of hardened concrete properties, such as compressive strength, ultrasonic pulse velocity, dynamic elasticity modulus, water absorption and depth of penetration under varying curing conditions having produced concrete samples using Portland cement (PC), slag cement (SC) and limestone cement (LC). The samples were produced at 0.63 and 0.70 w/c (water/cement) ratios. Hardened concrete samples were then cured under three conditions, namely standard (W), open air (A) and sealed plastic bag (B). Although it was found that the early-age strength of slag cement was lower, it was improved significantly on 90th day. In terms of the effect of curing conditions on compressive strength, cure W offered the highest compressive strength, as expected, while cure A offered slightly lower compressive strength levels. An increase in the w/c ratio was found to have a negative impact on pozzolanic reactions, which resulted in poor hardened concrete properties. Furthermore, carbonation effect was found to have positive effects on some of the concrete properties, and it was observed to have improved the depth of water penetration. Moreover, it was possible to estimate the compressive strength with high precision using artificial neural networks (ANN). The values of the slopes of the regression lines for training, validating and testing datasets were 0.9881, 0.9885 and 0.9776, respectively. This indicates the high accuracy of the developed model as well as a good correlation between the predicted compressive strength values and the experimental (measured) ones.

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