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.

Producing High Strength Hollow Core Reinforced Concrete Slab with Silica Fume and Polypropylene Fibers

2016 ◽  
Vol 866 ◽  
pp. 143-147
Author(s):  
Evalyn Joy M. Castil ◽  
Nathaniel C. Tarranza
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Flexural Strength ◽  
Silica Fume ◽  
Concrete Slab ◽  
Polypropylene Fiber ◽  
Optimum Combination ◽  
Hollow Core ◽  
Reinforced Concrete Slab ◽  
Concrete Mix

The compressive strength and workability of concrete mixes with the same proportion of cement, sand, gravel and water but with different amounts of silica fume and polypropylene fiber admixtures were investigated. The same concrete mixes were used for producing hollow core reinforced concrete (HCRC) slab-strip samples tested for flexural strength under third-point loading. The HCRC slab-strip samples were reinforced with the same number and size of reinforcing bars. Silica fume content of 0%, 5%, 10%, 15% and 20% by weight of cement, in combination with polypropylene fiber at 0 kg , 0.40 kg , 0.60 kg and 0.80 kg per cubic meter of concrete, were added into the concrete mix. Tests demonstrate that there is an optimum combination of silica fume and polypropylene fiber for maximum gain in concrete compressive strength of the concrete mix, and another optimum combination of the same admixtures for optimal gain in flexural strength of the HCRC slab-strip samples produced using the concrete mix.

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).

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 Strength Characteristics of High Strength Concrete (HSC) with and without Coarse Aggregate

2019 ◽  
Vol 9 (2) ◽  
pp. 4701-4704
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Flexural Strength ◽  
Silica Fume ◽  
High Strength Concrete ◽  
Mechanical Characteristics ◽  
Coarse Aggregate ◽  
High Strength ◽  
Set Up

This paper aimed to investigate the mechanical characteristics of HSC of M60 concrete adding 25% of fly ash to cement and sand and percentage variations of silica fumes 0%,5% and 10% to cement with varying sizes of 10mm,6mm,2mm and powder of granite aggregate with w/c of 0.32. Specimens are tested for compressive strength using 10cm X 10cmX10cm cubes for 7,14,28 days flexural strength was determined by using 10cmX10cmX50cm beam specimens at 28 days and 15cm diameter and 30cm height cylinder specimens at 28 days using super plasticizers of conplast 430 as a water reducing agent. In this paper the experimental set up is made to study the mechanical properties of HSC with and without coarse aggregate with varying sizes as 10mm, 6mm, 2mm and powder. Similarly, the effect of silica fume on HSC by varying its percentages as 0%, 5% and 10% in the mix studied. For all mixes 25% extra fly ash has been added for cement and sand.

scholarly journals The influence of cement-based composite materials on the performance of bridges: modification and optimization by nano-SiO2 material

2020 ◽  
Vol 15 (3) ◽  
pp. 409-413
Author(s):  
Cheng Zhu
Keyword(s):  
Compressive Strength ◽  
Composite Materials ◽  
Flexural Strength ◽  
Building Materials ◽  
Complex Environments ◽  
Nano Sio2 ◽  
Bending Resistance ◽  
Cement Based Materials ◽  
Different Content ◽  
Compression Resistance

Abstract Cement-based materials have been widely used in bridge construction. In order to further improve their performance, this study analyzed the modification and optimization functions of nano-SiO2 materials, designed test specimens with different content of nano-SiO2 and conducted experiments on their flow performance, compression resistance, bending resistance and impermeability. The results showed that the flow performance of the materials decreased and the impermeability decreased with the increase of nano-SiO2 content. The compressive strength and flexural strength are the best when the content of nano-SiO2 is 1%. On the whole, the best content of nano-SiO2 is 1%; when the content of nano-SiO2 is 1%, all the properties of the specimens are good, which is more conducive to the construction of bridges in various complex environments. The research in this paper has made some contributions to the further application of nano-SiO2 in the optimization of building materials, which is conducive to the better development of building materials.

Polypropylene Fiber Reinforced Concrete for Airport Rigid Pavements: Compressive and Flexural Strength

2011 ◽  
Vol 219-220 ◽  
pp. 1601-1607 ◽  
Author(s):  
Tammam Merhej ◽  
Xin Kai Li ◽  
De Cheng Feng
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Flexural Strength ◽  
Volume Fraction ◽  
Linear Regression Analysis ◽  
Polypropylene Fiber ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Rigid Pavements ◽  
Polypropylene Fiber Reinforced Concrete

This paper presents the experimental investigation carried out to study the behavior of polypropylene fiber reinforced concrete (PPFRC) under compression and flexure. Crimped polypropylene fibers and twisted polypropylene fiber were used with 0.0%, 0.2%, 0.4% and 0.6% volume fractions. The influence of the volume fraction of each shape of polypropylene fiber on the compressive strength and flexural strength is presented. Empirical equations to predict the effect of polypropylene fiber on compressive and flexural strength of concrete were proposed using linear regression analysis. An increase of 27% in flexural strength was obtained when 0.6% volume fraction of twisted polypropylene fiber was added. It was also found that the contribution of fiber in flexural strength is more effective when twisted fibers were used. The compressive strength was found to be less affected by polypropylene fiber addition.

Effect of Polypropylene Fiber on Strength and Flexural Properties of Concrete Containing Silica Fume

2011 ◽  
Vol 346 ◽  
pp. 30-33
Author(s):  
Hong Wei Wang
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Silica Fume ◽  
Modulus Of Elasticity ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Flexural Modulus ◽  
Polypropylene Fiber ◽  
Flexural Properties ◽  
Fiber Volume

A designed experimental study has been conducted to investigate the effect of polypropylene fiber on the compressive strength and flexural properties of concrete containing silica fume, a large number of experiments have been carried out in this study. The flexural properties include flexural strength and flexural modulus of elasticity. On the basis of the experimental results of the specimens of six sets of mix proportions, the mechanism of action of polypropylene fiber on compressive strength, flexural strength and flexural modulus of elasticity has been analyzed in details. The results indicate that there is a tendency of increase in the compressive strength and flexural strength, and the flexural modulus of elasticity of concrete containing silica fume decrease gradually with the increase of fiber volume fraction.

scholarly journals Mechanical Properties of Coarse Aggregate Electric Arc Furnace Slag in Cement Concrete

2021 ◽  
Vol 7 (10) ◽  
pp. 1716-1730
Author(s):  
Huu-Bang Tran
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Fly Ash ◽  
Flexural Strength ◽  
Silica Fume ◽  
Arc Furnace ◽  
Coarse Aggregates ◽  
Eaf Slag ◽  
Electric Arc Furnace Slag ◽  
Furnace Slag

The feasibility of using EAF slag aggregate, fly ash, and silica fume in pavement Electric Arc Furnace Slag Concrete (CEAFS) is the focus of this research. EAF slag aggregate is volume stable and suitable for use in concrete, according to the findings of the testing. EAF slag was utilized to replace natural coarse aggregates in the CEAFS mixes. CEAFS was created by blending 50% crushed stone with 50% EAF slag in coarse aggregates, with fly ash (FA) and silica fume (SF) partially replacing cement at content levels (i.e. FA: 0, 20, 30, and 40%; SF: 0, 5, and 10%). The soil compaction approach was used to evaluate the optimal moisture level for CEAFS mixes containing EAF slag aggregate fly ash and silica fume. A testing program was used to investigate the weight of CEAFS units and their mechanical qualities (compressive strength, flexural strength, and elastic modulus). As a result, the fresh and hardened unit weights in the CEAFS are comparable. Moreover, variations in the concentration of mineral additives FA and SF in adhesives, as well as the CEAFS mixed aggregate ratio, have an impact on compressive strength, flexural strength, and elastic modulus at all ages. However, combining EAF slag aggregate with (FA0% +SF10%; FA10% +SF0%; FA10% +SF10%; and FA20% +SF10%) the CEAFS mixtures have improved mechanical characteristics over time. According to this study, CEAFS pavements can be made with EAF slag aggregate fly ash and silica fume. In addition, a formula correlation was suggested to compute CEAFS (i.e. compressive strength with elastic modulus and compressive strength with flexural strength). Doi: 10.28991/cej-2021-03091755 Full Text: PDF

scholarly journals Flexural Behaviour of RCC Beams Partially Replacing Cement by Dolomite Powder and Sand by Quarry Dust

2019 ◽  
Vol 8 (12) ◽  
pp. 5280-5290
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Reinforced Concrete ◽  
Flexural Strength ◽  
Concrete Beams ◽  
Low Cost ◽  
Waste Material ◽  
Reinforced Concrete Beams ◽  
Split Tensile Strength ◽  
Quarry Dust

The present Investigation is aimed at utilizing low cost material Dolomite powder and waste material Quarry dust as partial replacement of cement and sand in concrete. This experimental investigation is carried out in three stages. In 1st stage M25 grade of concrete is produced by replacing cement by 0%, 6%, 12% and 18% of Dolomite Powder. In 2nd Stage concrete is produced by keeping the optimum 12% of dolomite powder as constant and sand is replaced by quarry dust in the percentage of 0%, 25%, 35% and 45%. In 3rd stage the optimum percentage of Dolomite Powder and Quarry Dust (DP+QD) Concrete are used to determine the compressive strength, split tensile strength and flexural strength of concrete and to check the flexural behavior of RCC beams. It is found that the concrete made of low cost material dolomite powder and waste material quarry dust increases the compressive strength, split tensile strength and flexural strength of concrete when compared to that of normal concrete. It also concluded that the first crack load and ultimate load of dolomite powder and quarry dust reinforced concrete beams increases when compared with normal reinforced concrete beams. From study it is concluded that the low cost material Dolomite powder & Quarry dust can be used in construction works which results in construction cost. By using natural resources the environment is protected.

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