scholarly journals Behavior of bearing reinforced concrete panels in the process of combined action

2019 ◽  
Vol 265 ◽  
pp. 05037 ◽  
Author(s):  
Dmitry Korolchenko
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Reinforced Concrete ◽  
Manufacturing Technology ◽  
Concrete Panels ◽  
Labour Costs ◽  
Combined Action ◽  
Concrete Elements ◽  
Deflection Rate ◽  
Important Significance

This research of has important significance in the constructive solution, manufacturing technology and labour costs. The irreversible changes in mechanical properties occur in reinforced concrete elements, decrease in compressive and tensile strength, additional deflections. In this paper, the goal was to assess the behavior of the bearing reinforced concrete panels with a combined action (fire and force) as close as possible to the actual effect in a fire. It was necessary to solve the following tasks: to determine the dependence of deflection and deflection rate on the heating of the plate and the load acting on the panel, to determine the amount of concrete falling before breaking the integrity of the panel (the formation of through cracks, determine the degree of heating of the panel from the duration of fire and force.

Effect of combined drink cans and steel fibers on the impact resistance and mechanical properties of concrete

2020 ◽  
Vol 14 (2) ◽  
pp. 6734-6742
Author(s):  
A. Syamsir ◽  
S. M. Mubin ◽  
N. M. Nor ◽  
V. Anggraini ◽  
S. Nagappan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Reinforced Concrete ◽  
Impact Resistance ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Fiber Reinforced ◽  
Indirect Tensile ◽  
The Impact

This study investigated the combine effect of 0.2 % drink cans and steel fibers with volume fractions of 0%, 0.5%, 1%, 1.5%, 2%, 2.5% and 3% to the mechanical properties and impact resistance of concrete. Hooked-end steel fiber with 30 mm and 0.75 mm length and diameter, respectively was selected for this study.  The drinks cans fiber were twisted manually in order to increase friction between fiber and concrete. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the strength performance of concrete, especially the compressive strength, flexural strength and indirect tensile strength. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the compressive strength, flexural strength and indirect tensile strength by 2.3, 7, and 2 times as compare to batch 1, respectively. Moreover, the impact resistance of fiber reinforced concrete has increase by 7 times as compared to non-fiber concretes. Moreover, the impact resistance of fiber reinforced concrete consistently gave better results as compared to non-fiber concretes. The fiber reinforced concrete turned more ductile as the dosage of fibers was increased and ductility started to decrease slightly after optimum fiber dosage was reached. It was found that concrete with combination of 2% steel and 0.2% drink cans fibers showed the highest compressive, split tensile, flexural as well as impact strength.    

Influence of the Composition of Cement Mortars Modified by Lime or Polymers on the Mechanical Properties and Microstructure of Mortars

2013 ◽  
Vol 592-593 ◽  
pp. 647-650 ◽  
Author(s):  
Małgorzata Lenart
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Reinforced Concrete ◽  
Flexural Strength ◽  
Polyvinyl Alcohol ◽  
Polymer Composites ◽  
Adhesion Strength ◽  
Hardened Cement ◽  
Cement Mortars ◽  
Styrene Butadiene

Cement – polymer composites are nowadays widely used in repair systems not only in case of concrete or reinforced concrete constructions but also in masonry. Polymers addition for example already at 5% m.c. modifies the structure of the cement – polymer composite in a way that many of the mechanical properties such as flexural strength, tensile strength or adhesion to substrates are improved. The paper presents the results of tests such as flexural, compressive or adhesion strength to ceramic substrate of hardened cement mortars with different composition, as well as selected cement mortars modified by two polymers: polyvinyl alcohol and styrene – butadiene polymer dosed at 5 % m.c. Four types of cement mortars modified by lime (component used in historical constructions as well as in contemporary masonry mortars) are also examined for comparison.

scholarly journals Two-layer reinforced concrete panels with uniformly compressed sections

2020 ◽  
Vol 315 ◽  
pp. 07004
Author(s):  
Dmitry Mailyan ◽  
Alik Blyagoz ◽  
Konstantin Kretinin
Keyword(s):  
Reinforced Concrete ◽  
Cross Section ◽  
Concrete Panels ◽  
The Creation ◽  
Concrete Elements

The paper contains the issues related to the creation of a non-uniform prestress cross-section of reinforced concrete elements compressed during operation of working with a one-way eccentricity of the resultant longitudinal forces.

Effect of Fly Ash and Activator on Performance of Steam-Cured Concrete

2010 ◽  
Vol 113-116 ◽  
pp. 1013-1016 ◽  
Author(s):  
Zhi Min He ◽  
You Jun Xie ◽  
Guang Cheng Long ◽  
Jun Zhe Liu
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Fly Ash ◽  
Precast Concrete ◽  
Early Age ◽  
Flexure Strength ◽  
Concrete Elements ◽  
Chemical Activator

In precast concrete elements manufacturing, steam-cured concrete incorporating 30% fly ash encountered the problem of a too low demoulding compressive strength. To resolve it, this paper developed a new steam-cured concrete (AFSC) incorporating fly ash and a chemical activator. Experiments were conducted to investigate the mechanical properties of AFSC. The corresponding mechanism was also discussed by testing the microstructure of concrete. Results indicate that the demoulding compressive strength of AFSC can meet production requirements, and compressive and flexure strength of AFSC at later ages increase well. Compared with that of ordinary steam-cured concrete, AFSC has a higher tensile strength, and the capability of AFSC to resist cracks is enhanced remarkably. At an early age, addition of the chemical activator can distinctly accelerate the extent of hydration of the fly ash cement systems, and thus the microstructure of concrete becomes denser.

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.

scholarly journals Experimental Study on Mechanical Properties of High Performance Hybrid Fiber Concrete for Shaft Lining

2021 ◽  
Vol 11 (17) ◽  
pp. 7926
Author(s):  
Qian Zhang ◽  
Wenqing Zhang ◽  
Yu Fang ◽  
Yongjie Xu ◽  
Xianwen Huang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Reinforced Concrete ◽  
Reference Group ◽  
Splitting Tensile Strength ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Hybrid Fiber ◽  
Fiber Concrete ◽  
Shaft Lining

In order to solve the problem of highly brittle shaft lining under dynamic loading, a combination of hybrid fiber concrete mixed with steel and polypropylene fiber is proposed to make shaft lining. C60, the concrete commonly used in shaft lining, was selected as the reference group. The static mechanical properties, dynamic mechanical properties, and crack failure characteristics of the hybrid fiber concrete were experimentally studied. The test results showed that compared to the reference group concrete, the compressive strength of the hybrid fiber-reinforced concrete did not significantly increase, but the splitting tensile strength increased by 60.4%. The split Hopkinson compression bar results showed that the optimal group peak stress and peak strain of the hybrid fiber concrete increased by 58.2% and 79.2%, respectively, and the dynamic toughness increased by 68.1%. The strain distribution before visible cracks was analyzed by the DIC technology. The results showed that the strain dispersion phenomenon of the fiber-reinforced concrete specimen was stronger than that of the reference group concrete. By comparing the crack failure forms of the specimens, it was found that compared to the reference group concrete, the fiber-reinforced concrete specimens showed the characteristics of continuous and slow ductile failure. The above results suggest that HFRC has significantly high dynamic splitting tensile strength and compressive deformation capacity, as well as a certain anti-disturbance effect. It is an excellent construction material for deep mines under complex working conditions.

scholarly journals SCOPE OF IMPROVING MECHANICAL CHARACTERISTICS OF CONCRETE USING NATURAL FIBER AS A REINFORCING MATERIAL

2020 ◽  
Vol 32 (2) ◽  
Author(s):  
Sristi Das Gupta ◽  
MD Shahnewaz Aftab ◽  
Hasan Mohammod Zakaria ◽  
Chaity Karmakar
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Reinforced Concrete ◽  
Fiber Reinforced Concrete ◽  
Synthetic Fiber ◽  
Jute Fiber ◽  
Fiber Reinforced ◽  
Plastic Shrinkage ◽  
Shrinkage Cracks ◽  
Reinforcing Material

Using natural (Jute) fiber in concrete as a reinforcing material can not only augment the concrete strength but also restrict the use of synthetic fiber which is environmentally detrimental. To achieve this goal, this study evaluated compressive strength, tensile strength and plastic shrinkage of concrete incorporating ‘Natural (Jute)’ fiber of different length (15 mm and 25 mm) with various mix proportions of 0.10%, 0.2%, 0.3% and 0.4% respectively by volume of concrete. Concrete is vulnerable to grow shrinkage cracks because of high evaporation rate in dry and windy conditions. Incorporating of fibers could abate development of this crack. The large length (25 mm) and higher content ( 0.3%) of reinforcing materials (jute fiber) result to the lowering of mechanical properties of JFRC compare to plain concrete. But in the incorporation of short (15 mm) and low fiber content ( 0.3%), enhances the mechanical properties of the same JFRC. Inclusion of 0.3% (15 mm length) fiber gave maximum enhancement of both concrete compressive and tensile strength by 12.4% and 58% respectively compared to the non-fiber reinforced concrete. A drastic suppression of crack occurrence and area of crack between non-fiber reinforced concrete and fiber reinforced concretes was attained. Experimental results of incorporating 0.1–0.4% fiber with 15 mm length in concrete revealed that plastic shrinkage cracks were decreased by 75–99% in contrast to non-fiber reinforced concrete. Therefore, it is concluded that the incorporation of jute fiber in making FRC composite would be one of the favorable methods to enhance the performance of concrete.

scholarly journals Historical reinforced concrete structures – used materials and calculating algorithms

2015 ◽  
Vol 14 (2) ◽  
pp. 105-112 ◽  
Author(s):  
Bartosz Szostak ◽  
Maciej Trochonowicz
Keyword(s):  
Mechanical Properties ◽  
Reinforced Concrete ◽  
Concrete Structures ◽  
Reinforced Concrete Structures ◽  
Structural Element ◽  
Historical Building ◽  
Historical Material ◽  
Low Strength ◽  
Concrete Elements

During designing in historical object we can have a problem with historical reinforced concrete elements. Many designers, classifies this elements as low strength. They are convicted that this type of elements in historical building can be only a monument and cannot be used in this construction as an structural element. It is very important in this type of buildings to keep as many historical material as it is possible. Authors researched the literature which has been a guide in the design and execution of these elements. By comprising used algorithms and physico-mechanical properties of old materials with algorithms and materials, which are using today, we are able to estimate the strength of such elements.

scholarly journals Mechanical Properties of Macro Polypropylene Fibre-Reinforced Concrete

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4112
Author(s):  
Rajab Abousnina ◽  
Sachindra Premasiri ◽  
Vilive Anise ◽  
Weena Lokuge ◽  
Vanissorn Vimonsatit ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Reinforced Concrete ◽  
Plain Concrete ◽  
Modulus Of Rupture ◽  
Fibre Reinforced Concrete ◽  
Empirical Formulas ◽  
Pull Out ◽  
Mechanical And Microstructural Properties

Adding fibers to concrete helps enhance its tensile strength and ductility. Synthetic fibres are preferable to steel ones which suffer from corrosion that reduces their functionality with time. More consideration is given to synthetic fibres as they can be sourced from waste plastics and their incorporation in concrete is considered a new recycling pathway. Thus, this work investigates the potential engineering benefits of a pioneering application using extruded macro polyfibres in concrete. Two different fiber dosages, 4 kg/m3 and 6 kg/m3, were used to investigate their influence based on several physical, mechanical and microstructural tests, including workability, compressive strength, modulus of elasticity, splitting-tensile strength, flexural test, CMOD, pull-out test and porosity. The test results revealed a slight decrease in the workability of the fibre-reinforced concrete, while all the mechanical and microstructural properties were enhanced significantly. It was observed that the compressive, splitting tensile and bonding strength of the concrete with 6 kg/m3 fibre dosage increased by 19.4%, 41.9% and 17.8% compared to the plain concrete specimens, respectively. Although there was no impact of the fibres on the modulus of rupture, they significantly increased the toughness, resulting in a progressive type of failure instead of the sudden and brittle type. Moreover, the macroporosity was reduced by the fibre addition, thus increasing the concrete compressive strength. Finally, simplified empirical formulas were developed to predict the mechanical properties of the concrete with fibre addition. The outcome of this study will help to increase the implementation of the recycled plastic waste in concrete mix design and promote a circular economy in the waste industry.

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