scholarly journals EXPERIMENTAL INVESTIGATION OF INTERNAL FRICTION IN RUBBER CONCRETE AND FIBER-REINFORCED RUBBER CONCRETE

2021 ◽  
pp. 53-62
Author(s):  
I. Popov ◽  
A. Levchenko
Keyword(s):  
Internal Friction ◽  
Opposite Effect ◽  
Polymer Concrete ◽  
Butadiene Rubber ◽  
Building Structures ◽  
Fiber Reinforced ◽  
Damping Material ◽  
Impulse Excitation ◽  
First Time ◽  
Rubber Concrete

Statement of the problem. The paper is devoted to the experimental identification of damping for such materials as butadiene rubber (BR) and cis-butadiene low-molecular weight rubber (SKDN-N) based concrete and fiber-reinforced rubber concrete by means of the Impulse Excitation Technique (IET). Results. It was found that BR based concrete with or without fiber-reinforcement shows more obvious viscoelastic properties than the corresponding materials based on SKDN-N rubber. The addition of steel fiber reduces internal friction in the material, while propylene fiber has the opposite effect. This is due to the fact that the fibrous propylene acts as an additional damping material, which enhances energy dissipation under dynamic loading.Conclusion. The internal friction in the rubber concrete and fiber-reinforced rubber concrete was measured for the first time. The obtained data are the additional microstructural characteristics of polymer concrete, which describes its viscosity. The real values of the investigated quantities have been determined, which makes it possible to use the models with fractional derivatives in the calculations of building structures made of rubber concrete and fiber-reinforced rubber concrete for dynamic loads, taking into account the phenomenon of viscoelasticity.

Experimental Investigation of Internal Friction in Rubber Concrete and Fiber-Reinforced Rubber Concrete

2021 ◽  
pp. 83-92
Author(s):  
И. И. Попов ◽  
А. В. Левченко
Keyword(s):  
Internal Friction ◽  
Opposite Effect ◽  
Polymer Concrete ◽  
Butadiene Rubber ◽  
Building Structures ◽  
Fiber Reinforced ◽  
Damping Material ◽  
Impulse Excitation ◽  
First Time ◽  
Rubber Concrete

Постановка задачи. Работа посвящена экспериментальному определению внутреннего трения в таких материалах, как каучуковые бетоны (каутоны) на основе низкомолекулярного полибутадиенового каучука смешанной микроструктуры марки ПБН и цис-полибутадиенового низкомолекулярного каучука марки СКДН-Н, с помощью метода импульсного воздействия. Результаты. Установлено, что каутон на основе каучука марки ПБН обладает более выраженными вязкоупругими свойствами по сравнению с аналогичным материалом на основе каучука марки СКДН-Н. Введение стальной фибры снижает внутреннее трение в материале, в то время как полимерная фибра дает обратный эффект. Это связано с тем, что волокнистая пропиленовая фибра служит дополнительным демпфирующим материалом, усиливающим диссипацию энергии при динамическом нагружении. Выводы. Впервые измерено внутреннее трение для каутона и фиброкаутона. Полученные данные являются дополнительными микроструктурными характеристиками материалов, описывающими их вязкость. Определены реальные значения исследуемых величин, которые позволяют применять модели с дробными производными при расчете строительных конструкций из каутона и фиброкаутона на динамические воздействия с учетом явления вязкоупругости. Statement of the problem. The paper is devoted to the experimental identification of damping for such materials as butadiene rubber (BR) and cis-butadiene low-molecular weight rubber (SKDN-N) based concrete and fiber-reinforced rubber concrete by means of the Impulse Excitation Technique (IET). Results. It was found that BR based concrete with or without fiber-reinforcement shows more obvious viscoelastic properties than the corresponding materials based on SKDN-N rubber. The addition of steel fiber reduces internal friction in the material, while propylene fiber has the opposite effect. This is due to the fact that the fibrous propylene acts as an additional damping material, which enhances energy dissipation under dynamic loading. Conclusion. The internal friction in the rubber concrete and fiber-reinforced rubber concrete has been measured for the first time. The obtained data are the additional microstructural characteristics of polymer concrete, which describes its viscosity. The actual values of the investigated quantities have been determined, which makes it possible to use the models with fractional derivatives in the calculations of building structures made of rubber concrete and fiber-reinforced rubber concrete for dynamic loads taking into account the phenomenon of viscoelasticity.

scholarly journals Buildings Materials & Structures Based on Advanced Polymer Nanostructured Matrix

2014 ◽  
Vol 28 ◽  
pp. 103-114
Author(s):  
Rudolf Gizelter
Keyword(s):  
Composite Materials ◽  
Polymer Composite ◽  
Constructional Material ◽  
Polymer Composite Materials ◽  
Polymer Concrete ◽  
Building Structures ◽  
Technological Properties ◽  
Viscous Liquids ◽  
New Class ◽  
Rubber Concrete

Development of manufacture of linear diene oligomers belonging to a liquid rubbers class with viscous liquids consistence allowed to create a new class of conglomerate polymer composite materials - rubber concrete (RubCon®). Rubber concrete is the advanced constructional material created for last years. It is polymer concrete with a unique set of physical-mechanical, chemical and technological properties which allow to obtain highly effective building structures and products on its basis.

scholarly journals Influence of the addition of styrene-butadiene rubber on the dynamic properties of polymer concrete for machine tool applications

2019 ◽  
Vol 11 (7) ◽  
pp. 168781401986584 ◽  
Author(s):  
Norbert Kepczak
Keyword(s):  
Relaxation Time ◽  
Transfer Function ◽  
Dynamic Properties ◽  
Damping Ratio ◽  
Styrene Butadiene Rubber ◽  
Polymer Concrete ◽  
Butadiene Rubber ◽  
Grain Sizes ◽  
Impulse Excitation ◽  
Styrene Butadiene

In this study, the influence of the addition of styrene-butadiene rubber on the dynamic properties of polymer concrete was investigated. A 10% volume addition of styrene-butadiene rubber granulate with three different grain gradations was used for the tests. The modal study was carried out in the 0 to 2000 Hz frequency range. The response function for a single impulse excitation was tested. The relaxation time after excitation, the modes of natural vibrations and the amplitude of the transfer function values as well as vibration damping ratios were also compared. Finally, conclusions were formulated regarding the application of the styrene-butadiene rubber additive as a material to improve the dynamic properties of polymer concrete. The best results were obtained for a sample made with a 10% styrene-butadiene rubber volume addition with grain sizes from 0.6 to 2 mm. In this case, the biggest decrease of the amplitude of the transfer function value was 76%, while the biggest increase of the damping ratio was 431.5%, in comparison with the clear polymer concrete sample. The worst results were obtained for a sample made with a 10% styrene-butadiene rubber volume addition with grain sizes from 2.5 to 6 mm. In this case, the longest relaxation time of the sample, the increase of the amplitude of the transfer function value and the decrease in the damping coefficient were recorded.

Young modulus and internal friction of a fiber‐reinforced composite

1986 ◽  
Vol 59 (6) ◽  
pp. 1972-1976 ◽  
Author(s):  
H. M. Ledbetter ◽  
Ming Lei ◽  
M. W. Austin
Keyword(s):  
Internal Friction ◽  
Young Modulus ◽  
Fiber Reinforced ◽  
Fiber Reinforced Composite ◽  
Reinforced Composite

Experimental Testing of Fiber Reinforced Polymer-Concrete Composite Beam

2010 ◽  
Vol 168-170 ◽  
pp. 549-552
Author(s):  
Yan Lei Wang ◽  
Qing Duo Hao ◽  
Jin Ping Ou
Keyword(s):  
Composite Beam ◽  
Experimental Testing ◽  
Coarse Sand ◽  
Fiber Reinforced Polymer ◽  
Bending Test ◽  
Polymer Concrete ◽  
Fiber Reinforced ◽  
Four Point Bending ◽  
Reinforced Polymer ◽  
Box Beam

A new form of fiber reinforced polymer (FRP)-concrete composite beam is proposed in this study. The proposed composite beam consists of a GFRP box beam combined with a thin layer of concrete in the compression zone. The interaction between the GFRP beam and the concrete was obtained by bonding coarse-sand on the top flange of the GFRP beam. One GFRP box beam and one GFRP-concrete composite beam were investigated in four-point bending test. Load-deflection response, mid-span longitudinal strain distributions and interface slip between GFRP beam and the concrete for the proposed composite beam were studied. Following conclusions are drawn from this study: (1) the stiffness and strength of the composite beam has been significantly increased, and the cost-to-stiffness ratio of the composite beam has been drastically reduced comparing with GFRP-only box beam; (2) a good composite action has been achieved between the GFRP beam and the concrete; (3) crushing of concrete in compression defines flexural collapse of the proposed composite beam..

scholarly journals First building engineers in architectural practice of St. Petersburg at the beginning of the 19th century

2020 ◽  
Vol 164 ◽  
pp. 05011
Author(s):  
Ekaterina Vozniak ◽  
Svetlana Golovina ◽  
Maria Kolesova
Keyword(s):  
Civil Engineer ◽  
Urban Development ◽  
Engineering Education ◽  
19Th Century ◽  
Building Structures ◽  
Next Generation ◽  
Bridge Construction ◽  
Architectural Practice ◽  
The 19Th Century ◽  
First Time

The emergence of the specialty of civil engineer in the first half of the 19th century had a significant impact on architectural practice in St. Petersburg. The differentiation of the professions of engineer and architect took place for the first time; both specialists began to participate in the design. The appearance of such engineers as Augustine Betancourt, Matvey Clark, Pierre-Dominique Bazin and Wilhelm von Tretter brought about changes in all areas of architecture and construction. New building structures and materials appeared, as well as methods for checking and calculating. Designing has become comprehensive, the activities of the Committee for Structures and Hydraulic Works led by Betancourt covered urban development, individual buildings and all types of utilities. The formation of engineering education took place, which brought up the next generation of Russian engineers.The article considers the most important aspects of the activities of Augustine Betancourt, who laid the foundations for engineering education in Russia; Matvey Clark, who created the first metal beams and trusses; Pierre Dominique Bazin, who continued the development of engineering education, as well as Wilhelm von Tretter, one of the founders of iron bridge construction in Russia.

scholarly journals Modeling Punching Shear Capacity of Fiber-Reinforced Polymer Concrete Slabs: A Comparative Study of Instance-Based and Neural Network Learning

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Nhat-Duc Hoang ◽  
Duy-Thang Vu ◽  
Xuan-Linh Tran ◽  
Van-Duc Tran
Keyword(s):  
Neural Network ◽  
Regression Model ◽  
Shear Capacity ◽  
Fiber Reinforced Polymer ◽  
Punching Shear ◽  
Polymer Concrete ◽  
Concrete Slabs ◽  
Fiber Reinforced ◽  
Reinforced Concrete Slabs ◽  
Reinforced Polymer

This study investigates an adaptive-weighted instanced-based learning, for the prediction of the ultimate punching shear capacity (UPSC) of fiber-reinforced polymer- (FRP-) reinforced slabs. The concept of the new method is to employ the Differential Evolution to construct an adaptive instance-based regression model. The performance of the proposed model is compared to those of Artificial Neural Network (ANN) and traditional formula-based methods. A dataset which contains the testing results of FRP-reinforced concrete slabs has been collected to establish and verify new approach. This study shows that the investigated instance-based regression model is capable of delivering the prediction result which is far more accurate than traditional formulas and very competitive with the black-box approach of ANN. Furthermore, the proposed adaptive-weighted instanced-based learning provides a means for quantifying the relevancy of each factor used for the prediction of UPSC of FRP-reinforced slabs.

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