scholarly journals Effect of Fiber Reinforcement on the Compression and Flexural Strength of Fiber-Reinforced Geopolymers

2021 ◽  
Vol 11 (21) ◽  
pp. 10443
Author(s):  
Michał Łach ◽  
Bartłomiej Kluska ◽  
Damian Janus ◽  
Dawid Kabat ◽  
Kinga Pławecka ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Building Materials ◽  
Bending Strength ◽  
Strength Properties ◽  
Attractive Alternative ◽  
Reinforcing Fibers ◽  
Different Types ◽  
The Matrix ◽  
Glass Carbon

This work aimed to determine the effect of the addition of different types of reinforcing fibers on the strength properties of geopolymers such as flexural and compressive strength. Geopolymers are an attractive alternative to conventional binders and building materials; however, one of the main problems of their widespread use is their low resistance to brittle fracture. To improve the mechanical properties, reinforcement in the form of glass, carbon, and basalt fibers (as grids) was applied to geopolymers in the following work. Additionally, composites with these fibers were produced not only in the matrix of pure geopolymer but also as a hybrid variant with the addition of cement. Furthermore, basalt grids were used as reinforcement for geopolymers not only based on ash but also metakaolin. An additional variable used in the study was the molar concentration of the alkali solution (5 M and 10 M) for the different types of geopolymer samples. The mechanical properties of geopolymer materials and geopolymer–cement hybrids are the highest when reinforcement in the form of carbon fiber is used. Strength values for geopolymers reinforced with basalt mats depend on the number of reinforcement layers and the concentration of the alkaline solution used. All produced composites were tested for compressive strength and bending strength. When using basalt mesh, it was possible to achieve a bending strength of 12 MPa. The highest compressive strength that was achieved was the value of 66 MPa, while for samples not reinforced with fibers, only about 40 MPa was achieved.

scholarly journals Influence of water to solid ratio on mechanical properties of GBFS-based geopolymer foam concrete

2018 ◽  
Vol 163 ◽  
pp. 06003
Author(s):  
Tomasz Piotrowski ◽  
Piotr Prochoń
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Sodium Silicate ◽  
Building Materials ◽  
Bending Strength ◽  
Sodium Silicate Solution ◽  
Volume Density ◽  
Foam Concrete ◽  
Solid Ratio ◽  
Solid Part

The development of sustainable building materials with reduced environmental footprint in both, manufacturing and operational phases of the material lifecycle, is attracting increased interest in the construction industry worldwide. A recent innovation, the geopolymer foam concrete, combines the performance benefits and operational energy savings achievable through the use of lightweight foam concrete, with the cradle-togate emissions reductions obtained through the use of a geopolymer binder derived from granulated blast-furnace slag (GBFS). In this study mechanical properties of GBFS-based foam concrete were investigated for samples of different water to solid ratio (0.252, 0.287 and 0.321). According to ASTM C 796-97 both mass of the foaming solution and water in sodium silicate solution was considered as part of the total amount of mixing water. As a solid part, GBFS and solid part of activators (NaOH and sodium silicate) was accounted. A group of specimens (40x40x160 beams and 100x100x100 cubes) have been prepared and volume density, bending, compressive strength tests have been performed. In a result an optimized lightweight GBFS-based geopolymer foam concrete was obtained, characterized by 1.8 kg/dm3 volume density, 2.6 MPa bending strength and 51.8 MPa compressive strength measured on beams and 44.1 MPa compressive strength on cubes.

scholarly journals Evolution of the Mechanical Properties and Cracking Pattern of Cementitious Composites Reinforced with Hooked Steel Fibers

2020 ◽  
Vol 16 (1) ◽  
pp. 119-130
Author(s):  
Hamid Ranjbar ◽  
Ali Jadidi ◽  
Hosein Amerei
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Bending Strength ◽  
Tensile Specimen ◽  
Steel Fibers ◽  
Micro Cracks ◽  
The Matrix ◽  
Materials Used ◽  
Cracking Pattern

AbstractDegradation and disintegration of concrete depend on the formation of cracks and micro cracks intensively. With increase loading, micro cracks are linked together and form cracks. To solve the problem and to provide the homogenous condition, a series of thin fibers having been spread through the volume of concrete are used in the several last decades and they are called as fibers. In the study, the steel fibers integrated in the different percentages of weight have been investigated. The performance of fibers has been studied how to increase compressive strength, tensile strength, and bending strength. To survey compressive strength, tensile strength, and bending strength in the produced concrete, three plans of mixtures including the different percentages of the steel fibers have been examined. The results show that compressive strength in the concrete reinforced with steel fibers relies mainly on the quality of mortar. The added steel fibers cause the inconsiderable changes in the compressive strength of concrete. The results demonstrate that the concrete reinforced with steel fibers increase tensile strength considerably. The more the volume of steel fibers is, the more tensile strength is. Pozzolanic materials used in the specimens reinforced in steel fibers improve tensile strength. To investigate bending strength of the specimens reinforced with steel fibers, the study has used 4-point loading system. Generally, steel fibers used in the concrete increase bending strength of the concrete. The results indicate the increased steel fibers enhance bending strength in three plans of mixtures. Among the specimen reinforced with steel fibres, the most mechanical properties are related to the plans including 1, 1.5, and 2 percentages of dramix hooked steel fibers in the study. To examine crack pattern of the matrix tensile specimen reinforced with the different percentages of fibers, parameters such as the number of cracks, width of cracks, and distance between them are investigated.

scholarly journals Mechanical properties of the gypsum composite reinforcement with wooden fibers

2019 ◽  
Vol 10 (1) ◽  
pp. 15-21 ◽  
Author(s):  
Markéta Hošťálková ◽  
Nikola Vavřínová ◽  
Veronika Longauerová
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Shear Strength ◽  
Flexural Strength ◽  
Physical Properties ◽  
Building Materials ◽  
Strength Properties ◽  
Physical Parameters ◽  
Fibrous Materials ◽  
Mechanical And Physical Properties

The gypsum is one of the most often used materials in the civil engineering. Very often it is applied in the form of plasterboards without any reinforcement, for example, cladding boards are unusable as supporting construction. To improve the mechanical properties of plasterboards, fibrous materials such as cellulose or glass fiber are added. Reinforcement of gypsum with fibers improves in particular the flexural and shear strength. The main purpose of the research is to clarify whether natural wooden fibers could be used as the reinforced of composite gypsum building materials. Wooden fibers are used as a blown or board thermal insulation. This article presents the results of tests aimed at determining the mechanical and physical properties of gypsum composite reinforced with wooden fibers. The effect of the reinforcement on the strength properties as a compressive strength, flexural strength was verified on a series of test specimens. The results of the tests have shown that the reinforcing of gypsum composite has an impact on the mechanical-physical parameters.

scholarly journals MECHANICAL PROPERTIES OF RAMMED EARTH WITH RESPECT TO CLAY MIXTURE COMPOSITION

2019 ◽  
Vol 59 (4) ◽  
pp. 372-383
Author(s):  
Tereza Plaček Otcovská ◽  
Barbora Mužíková ◽  
Pavel Padevět
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Experimental Determination ◽  
Building Material ◽  
Building Materials ◽  
Bending Strength ◽  
Mixture Composition ◽  
Rammed Earth ◽  
Load Bearing

Unfired earth is a traditional building material, but it is less used than other building materials, such as concrete or steel. But the use of unfired earth is experiencing a renaissance. ammed earth is a type of unfired earth and is usually used for load bearing structures. This paper descries an experimental determination of the tensile bending strength and compressive strength of the rammed earth specimens with known compositions. Mechanical properties are dependent on these compositions (kind of clay, amount of clay, amount of mixture water). Laboratory specimens were produced without inorganic binders or fibrous admixtures. We observed higher tensile bending strengths and lower compressive strengths in specimen mixtures containing more clay. The obtained results were evaluated in a context of a previous research. The results were also compared with results published by another author.

scholarly journals Effects of load types and critical molar ratios on strength properties and geopolymerization mechanism

2021 ◽  
Vol 60 (1) ◽  
pp. 216-222
Author(s):  
Tao Meng ◽  
Sara Ahmed ◽  
Dawang Dai ◽  
Yue Yu
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Bending Strength ◽  
Strength Properties ◽  
Degree Of Polymerization ◽  
Molar Ratio ◽  
Molar Ratios ◽  
Loading Patterns ◽  
Load Types ◽  
The Relationship

Abstract In this study, the effect of SiO2/Al2O3 (S/A), Na2O/Al2O3 (N/A) and H2O/Na2O (H/N) molar ratios on bending and compressive strength of geopolymer were investigated. The geopolymerization mechanism was also analyzed from microstructure difference by FTIR. The experimental results showed that compressive strength and bending strength of geopolymer has an opposite reaction under different critical molar ratios. The increase of S/A molar ratio and the decrease of N/A and H/N molar ratios have resulted in an increase of the compressive strength. However, it caused a noticeable decrease in bending strength. The microstructure of geopolymer indicated that the degree of polymerization and cohesion of geopolymer have systematical depending on these critical molar ratios, making the mechanical properties of geopolymer susceptible to different types of loads. This paper reveals the relationship between the microstructure of geopolymer and different mechanical properties and helps to selectively prepare corresponding geopolymer for different loading patterns.

scholarly journals The Effect of Different Types of Internal Curing Liquid on the Properties of Alkali-Activated Slag (AAS) Mortar

2021 ◽  
Vol 13 (4) ◽  
pp. 2407
Author(s):  
Guang-Zhu Zhang ◽  
Xiao-Yong Wang ◽  
Tae-Wan Kim ◽  
Jong-Yeon Lim ◽  
Yi Han
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Deionized Water ◽  
Internal Curing ◽  
Control Group ◽  
Alkali Activated Slag ◽  
Different Types ◽  
Naoh Solution ◽  
Activated Slag ◽  
Alkali Activated

This study shows the effect of different types of internal curing liquid on the properties of alkali-activated slag (AAS) mortar. NaOH solution and deionized water were used as the liquid internal curing agents and zeolite sand was the internal curing agent that replaced the standard sand at 15% and 30%, respectively. Experiments on the mechanical properties, hydration kinetics, autogenous shrinkage (AS), internal temperature, internal relative humidity, surface electrical resistivity, ultrasonic pulse velocity (UPV), and setting time were performed. The conclusions are as follows: (1) the setting times of AAS mortars with internal curing by water were longer than those of internal curing by NaOH solution. (2) NaOH solution more effectively reduces the AS of AAS mortars than water when used as an internal curing liquid. (3) The cumulative heat of the AAS mortar when using water for internal curing is substantially reduced compared to the control group. (4) For the AAS mortars with NaOH solution as an internal curing liquid, compared with the control specimen, the compressive strength results are increased. However, a decrease in compressive strength values occurs when water is used as an internal curing liquid in the AAS mortar. (5) The UPV decreases as the content of zeolite sand that replaces the standard sand increases. (6) When internal curing is carried out with water as the internal curing liquid, the surface resistivity values of the AAS mortar are higher than when the alkali solution is used as the internal curing liquid. To sum up, both NaOH and deionized water are effective as internal curing liquids, but the NaOH solution shows a better performance in terms of reducing shrinkage and improving mechanical properties than deionized water.

scholarly journals Influence of Alumina Nanofibers Sintered by the Spark Plasma Method on Nickel Mechanical Properties

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 548 ◽  
Author(s):  
Leonid Agureev ◽  
Valeriy Kostikov ◽  
Zhanna Eremeeva ◽  
Svetlana Savushkina ◽  
Boris Ivanov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Strength Properties ◽  
Alumina Nanoparticles ◽  
Metal Powders ◽  
Wide Range ◽  
The Matrix ◽  
Spark Plasma ◽  
Average Size

The article presents the study of alumina nanoparticles’ (nanofibers) concentration effect on the strength properties of pure nickel. The samples were obtained by spark plasma sintering of previously mechanically activated metal powders. The dependence of the grain size and the relative density of compacts on the number of nanofibers was investigated. It was found that with an increase in the concentration of nanofibers, the average size of the matrix particles decreased. The effects of the nanoparticle concentration (0.01–0.1 wt.%) on the elastic modulus and tensile strength were determined for materials at 25 °C, 400 °C, and 750 °C. It was shown that with an increase in the concentration of nanofibers, a 10–40% increase in the elastic modulus and ultimate tensile strength occurred. A comparison of the mechanical properties of nickel in a wide range of temperatures, obtained in this work with materials made by various technologies, is carried out. A description of nanofibers’ mechanisms of influence on the structure and mechanical properties of nickel is given. The possible impact of impurity phases on the properties of nickel is estimated. The tendency of changes in the mechanical properties of nickel, depending on the concentration of nanofibers, is shown.

Preparation and Mechanical Properties of Polyethylene-Portland Cement Composites

2009 ◽  
Vol 1242 ◽  
Author(s):  
Rivas-Vázquez L.P. ◽  
Suárez-Orduña R. ◽  
Valera-Zaragoza M. ◽  
Máas-Díaz A. De la L. ◽  
Ramírez-Vargas E.
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Portland Cement ◽  
Plastic Waste ◽  
Cement Composites ◽  
Compression Tests ◽  
Standard Samples ◽  
Cement Ratio ◽  
Reinforcing Fibers ◽  
Waste Polyethylene

ABSTRACTThe effects of waste polyethylene aggregate as admixture agent in Portland cement at different addition polyethylene/cement ratios from 0.0156 to 0.3903 were investigated. The reinforced samples were prepared according the ASTM C 150 Standard (samples of 5 × 5 × 5 cm). The reinforcing fibers were milling at a size of 1/25 in diameter, form waste and used them to evaluate the effects in mechanical properties in cement-based composites. The evaluation of polyethylene as additive was based on results of density and compression tests. The 28-day compressive strength of cement reforced with plastic waste at a replacement polyethylene/cement ratio of 0.0468 was 23.5 MPa compared to the control concrete (7.5 MPa). The density of cement replaced with polyethylene varies from 2.114 (0% polyethylene) to 1.83 g/cm3 by the influence of polyethylene.

Fabrication and Mechanical Properties of Dense/Porous β-Tricalcium Phosphate Bioceramics

2007 ◽  
Vol 330-332 ◽  
pp. 907-910
Author(s):  
Fa Ming Zhang ◽  
Jiang Chang ◽  
Jian Xi Lu ◽  
Kai Li Lin
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Elastic Modulus ◽  
Exponential Growth ◽  
Weight Bearing ◽  
Area Ratio ◽  
Sectional Area ◽  
Cross Sectional ◽  
The Matrix ◽  
Porous Bioceramics

Attempt to increase the mechanical properties of porous bioceramics, a dense/porous structured β-TCP bioceramics that mimic the characteristics of nature bone were fabricated. Experimental results show that the dense/porous structured β-TCP bioceramics demonstrated excellent mechanical properties with compressive strength up to 74 MPa and elastic modulus up to 960 MPa, which could be tailored by the dense/porous cross-sectional area ratio obeying the rule of exponential growth. The interface between the dense and porous bioceramics is connected compactly and tightly with some micropores distributed in the matrix of both porous and dense counterparts. The dense/porous structure of β-TCP bioceramics may provide an effective way to increase the mechanical properties of porous bioceramics for bone regeneration at weight bearing sites.

Strength Properties of Activated Hwangtoh Mortars

2010 ◽  
Vol 168-170 ◽  
pp. 709-715
Author(s):  
Dongsik Oh ◽  
Doheom Song ◽  
Seongseok Go
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Building Materials ◽  
Strength Properties ◽  
Mixing Conditions ◽  
Substitution Ratio ◽  
Pozzolanic Properties ◽  
The Relationship ◽  
Furnace Slag

Hwangtoh (loess) has pozzolanic properties that mean it can be used as a cement admixture when activated at high temperatures, and that it can be used in combination with building materials such as fly ash or blast furnace slag. This study aimed to analyze the relationship between the compressive strength and the brick bond strength of various mortars containing hwangtoh, and also to find the optimum mixing conditions for the use of hwangtoh. It was found that the mortars’ strength properties are significantly influenced by the water/cement ratio W/C and the activated hwangtoh substitution ratio. We recommend the following materials and mixing conditions: W/C 60%, a cement substitution ratio of activated hwangtoh of 20 ~ 25%, and the addition of 10% blast furnace slag to improve the compressive strength of such mortars.

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