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Abstract

The study demonstrates and evaluates an approach in the structural analysis phase when assessing reinforced concrete slabs.

Due to different values of a parameter in the tests’ results, 10 models was crated for the first case study and 4 models for the second one.

In order to compare the results in terms of the flexural bearing capacity, the slabs were analyzed by using elastic finite element analysis and yield-line analysis.

Comparing the results shows that minor modification in the parameters associated with bearing capacity and the boundary conditions can affect the adequacy factor considerably, while the parameters those relate to boundary conditions affect the distribution of the yield lines.

Open access

Abstract

The structural assessment of historical buildings poses a significant challenge for engineers. However, when it comes to historical structures, more commonly used and reliable destructive testing may not always be viable. Instead, non-destructive testing has gained prominence, encompassing techniques like the Schmidt hammer test, georadar, and sonic-based tests.

In this paper, the viability of employing sonic testing on historical masonry structures was investigated. This study involves using the measured sonic velocities to identify voids and solid parts within masonry walls. In addition, the purpose is to determine the compressive strength of both mortar and brick constituents and to analyze the effects of moisture and compressive stress on the propagation velocity of waves.

Open access

Abstract

Concrete-filled steel tube columns are widely used in civil engineering structures due to their excellent ductility, energy absorption capacity, ultimate load-bearing capacity, and seismic behavior. In this paper, a numerical study modeling of eight lightweight concrete and conventional concrete filled steel tubes was carried out using ABAQUS software, and the lateral load-carrying capacity of square and circular steel tubes under cyclic load was compared. The quarter and one-third height of the tubes was filled with concrete with respect to the pier's height, to improve the base performance of the piers. The results show that the capacity of steel tubes filled with lightweight concrete increased by 40%–70% regarding energy absorption. The square tubes showed better performance than the circular tubes in terms of yielding load, yielding displacement, and energy dissipation.

Open access

Abstract

Concrete indeterminate flexural members represented by continuous beams reinforced with both fiber-reinforced polymers and steel bars in a way that allows for moment redistribution at failure are analyzed. The efficiency of introducing steel bars in the critical sections where plastic hinges are likely to form is evaluated in terms of reliability. Monte Carlo simulation and the concept of comparative reliability are both employed. Ultimately, the effect of different design parameters on the strength reduction factor is evaluated.

Open access
Pollack Periodica
Authors:
Souphavanh Senesavath
,
Ali Salem
,
Saied Kashkash
,
Bintul Zehra
, and
Zoltan Orban

Abstract

Steel fibers recovered from recycled tires were considered for use as reinforcement in concrete to improve the tensile properties of concrete as well as being an economically viable and environmentally friendly alternative. This paper investigates the effect of purified and non-purified recycled tire steel fiber in concrete with a constant fiber proportion of 30 kg m−3 to determine properties in fresh and hardened concrete. The results indicate that concrete with purified tire fibers have better tensile properties than those with non-purified tire fibers. Density, strength, and toughness significantly increase but workability tends to decrease when using recycled tire steel fiber as reinforcement in concrete.

Open access
Pollack Periodica
Authors:
Bintul Zehra
,
Ali Salem
,
Souphavanh Senesavath
,
Saied Kashkash
, and
Zoltan Orban

Abstract

Concrete is the most widely used construction material in the world. Over ten billion tons of concrete are being produced each year resulting in exhaustion of natural materials and an enormous carbon footprint. One of the primary goals of concrete technology today is to reduce the use of Portland cement and natural fine aggregates by partially replacing them with various waste materials and by-products of industrial processes. The paper summarizes the results of a study where the partial replacement of river sand and Portland cement was successfully applied using steel slag aggregate, silica fume and glass waste.

Open access

Abstract

Diagnostics is an important and challenging task of the structural analysis and condition assessment of historic masonry structures. However the interpretation of the results of the measurements, especially for buildings made from brick and stone, is to be more subjective than that for concrete structures. Therefore improvement of the reliability of the used techniques and finding better correlations between the test results and the mechanical properties of masonry has proven to be of great importance.

While several diagnostic procedures are commonly used in practice to test mechanical properties of masonry, e.g. Schmidt hammer test, analysis of drilled samples, penetration tests, etc. the results of these methods are considered reliable under laboratory conditions, several additional factors have to be taken into account in case of an in-situ application of these methods, that may largely affect the obtained results and conclusions. The results of the diagnostic procedures therefore need to be interpreted with a view to these environmental factors.

The paper focuses on the practical use of several test methods for historic masonries via a real case study. The presented case study attempts to demonstrate benefits from the combined application of Pendulum Schmidt Hammer, moisture meter and scanning electron microscopy.

Open access
International Review of Applied Sciences and Engineering
Authors:
Éva Bácsné Bába
,
György Norbert Szabados
,
Szabolcs Gergely Orbán
,
Zoltán Bács
,
Renátó Balogh
, and
Sándor Kovács

Abstract

Many sports organisations operate as non-profits, but the emphasis and role of for-profits in this sector cannot be avoided. Today, sports activities are connected to the business sector and generate profit, hence, sports sector is a decisive part of the economy. Sport profile companies differ in their organisational strategy formulation approach. The main focus was to learn more about their strategy approach and market behaviour. 350 sports business organisations were involved in a survey of 3,248 companies, and the Chi-square test, variance analysis, and principal component analysis were applied to the sample. Results showed that 75.7% of the responding sports companies had no written strategic plan. The availability of written strategies seemed to depend on the organisation's scale. The market-following behaviour was confirmed in the case of smaller sports enterprises. Fitness service providers appeared to follow a market-leading behaviour. Growth, investment, and development naturally emerged as essential factors for companies with higher sales revenue and operating sports facilities, and they were relatively less important in sports goods production and trade. Most of the results showed that in the sports business sector, large-scale organisations focus on strategic-related issues more than other players in the industry.

Open access
Pollack Periodica
Authors:
Ivan V. Abramov
,
Pavel V. Lekomtsev
,
Аlexander V. Romanov
,
Аndrey V. Buchkin
,
Zarina S. Saidova
, and
Zoltan Orban

The paper presents an experimental research on anchoring devices developed for the pre-tensioning of fiber reinforced polymer tendons in the stress range between 40 and 70% of tensile strength. The technique of testing, the criteria of assessing the load capacity and the influence of preloading applied on the anchor wedges on the initial tendons slippage are described. The optimal technical configurations of the anchoring device have been obtained, including parameters regarding the necessary prior anchorage of the tendon ends based on the strength properties of the tendon bar and the requirements to avoid slippage during the tensile tests.

Open access