Theoretic-Strength Concept of a Model Describing the Destruction of the Corner Part of a Slab-Column Structure

2015 ◽  
Vol 240 ◽  
pp. 225-231 ◽  
Author(s):  
Mirosław Wieczorek
Keyword(s):  
Reinforced Concrete ◽  
Cross Section ◽  
Laboratory Tests ◽  
Concrete Slab ◽  
Load Capacity ◽  
Limit Load ◽  
Traditional Theory ◽  
Load Step ◽  
Reinforced Concrete Slab ◽  
Column Structure

The paper presents a proposed theoretical-strength destruction model of the corner of a slab-column structure at 1:2 scale. The theoretical destruction model was developed on the basis of laboratory tests of a reinforced concrete slab with the dimensions 4000×4000×100 mm. The assumptions of the proposed theoretical model were based on a traditional theory of behaviour of reinforced concrete constructions. The method for calculating the strength of reinforced concrete sections is based on interaction graphs of the load capacity NRd, MRd,x and MRd,y. The calculation method takes into account the influence of changes in the shape of the cross-section of the analysed element on its limit load capacity in every load step.

scholarly journals Protection of the slab-column structures against progressive collapse

2020 ◽  
Vol 310 ◽  
pp. 00051
Author(s):  
Barbara Wieczorek
Keyword(s):  
Reinforced Concrete ◽  
Laboratory Tests ◽  
Concrete Slab ◽  
Load Capacity ◽  
Progressive Collapse ◽  
Experimental Studies ◽  
Optimal Method ◽  
Reinforced Concrete Slab ◽  
Support Zone

The paper presents the problem of protection of reinforced concrete slab-column structures against the occurrence of a progressive collapse caused by punching in the support zone. The experimental studies and effects of recorded collapses indicate the necessity to use the appropriate reinforcement type, which will significantly increase the load capacity of the slab-column connection after punching. One of the ways to protect the structure is to use an integrity reinforcement as the most optimal method of strengthening. The contents explain the reasons for the application and description of issues related to this type of reinforcement. The conclusions from the use of this reinforcement based on the results of laboratory tests were presented.

Influence of the Parameter of Ductility of Reinforcing Steel on the Behaviour of a Narrow Three-Span Reinforced Concrete Slab Based on Experimental Investigations

2015 ◽  
Vol 240 ◽  
pp. 218-224 ◽  
Author(s):  
Mirosław Wieczorek
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slab ◽  
Load Capacity ◽  
Experimental Tests ◽  
Experimental Investigations ◽  
Building Structures ◽  
Reinforced Concrete Slab ◽  
Tension Member ◽  
Test Models ◽  
Reinforced Steel

In the time of the exploitation of building structures frequently situations do occur, in which due to failures they are exposed to much higher loads than has been originally predicted. In a state of emergency due to overloading of the structure, significant reserves of load capacity may be appear in the case of a self-acting tension member work. The aim of the paper was to demonstrate the influence of reinforced steel parameters and its quantity on the mechanism of destruction of four three-span models of reinforced concrete strips with the dimensions 7140×500×190 mm. The paper contains the description of the test stand and test models and the results of experimental tests which were compared with the results of the calculations based on traditional methods.

scholarly journals CALCULATION OF RELIABILITY OF REINFORCED CONCRETE FLIGHT STRUCTURES

2021 ◽  
pp. 18-25
Author(s):  
Roman Kaplin
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slab ◽  
Load Capacity ◽  
Element Model ◽  
Operating Conditions ◽  
Structural Element ◽  
Reinforced Concrete Slab ◽  
Bridge Structures ◽  
Number Of Cycles ◽  
Office Software

A large number of bridges are operated on the roads of Ukraine. The increase in the intensity and speed of traffic leads to qualitative changes in the operating conditions of bridge structures, which is characterized by a sharp increase in the number of cycles under load of bridge elements, and to the development of damage in them. For trouble-free operation and efficient use of bridge structures it is very important to have reliable estimates of the actual load capacity and resource, taking into account the loads, material quality, nature of the structure. The solution of the problem in this statement is possible only on the basis of the theory of reliability. However, its application to specific assessments of durability and reliability of structures is associated with the solution of a set of issues: the identification of patterns of change of various parameters, the accumulation of reliable and easy to calculate statistics on loads and mechanical characteristics of materials, etc. It is necessary to know that the strength of the material (sample) of the structural element and the structure as a whole are completely different things. The article considers a new design of reinforced concrete girder structure, using perforated metal elements and an effective reinforced concrete slab of the carriageway. On its basis, a computational model in the form of a finite-element model built in the SCAD-Office software package is formed. As a result of calculations, the components of the stress-strain state of the structure are obtained. Based on the obtained results, the reliability of the structure was calculatedunder the influence of modern regulatory loads. 

scholarly journals Enhancing the Punching Load Capacity of Reinforced Concrete Slabs Using an External Epoxy-Steel Wire Mesh Composite

Fibers ◽  
2019 ◽  
Vol 7 (8) ◽  
pp. 68
Author(s):  
Abdulkhaliq A. Jaafer ◽  
Raid AL-Shadidi ◽  
Saba L. Kareem
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slab ◽  
Load Capacity ◽  
Steel Wire ◽  
Wire Mesh ◽  
Concrete Slabs ◽  
Reinforced Concrete Slab ◽  
Concentrated Load ◽  
Reinforced Concrete Slabs ◽  
Steel Wire Mesh

The present experimental work investigates the applicability and performance of a new strengthening method for concrete slabs, intended to increase their punching resistance using combination layers of steel wire mesh with epoxy attached to the concrete slabs’ tension face. Six simply supported square reinforced concrete slab specimens were tested up to failure under a central concentrated load. The main parameters in the study are the concrete compressive strength (30 MPa and 65 MPa) and the configuration of a bundle externally fixed to the tension side of the tested slabs. The experimental results appeared to greatly enhance the performance of the specimens, as they were externally strengthenined under this new method. When compared to the control slabs, the punching load and stiffness of the strengthened slabs increased up to 28% and 21%, respectively.

scholarly journals CRESTED SHEAR CONNECTORS APPLICATION TO COMBINE REINFORCED CONCRETE SLAB AND PLANK-NAILED STRUCTURE OF BRIDGE SPAN

2020 ◽  
Vol 17 (3) ◽  
pp. 414-427
Author(s):  
V. A. Utkin ◽  
I. I. Gotovtsev
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slab ◽  
Load Capacity ◽  
Beam Theory ◽  
Timber Structures ◽  
Bottom Part ◽  
Reinforced Concrete Slab ◽  
Composite Action ◽  
Shear Connectors ◽  
The Usa

Introduction. The construction of bridges using timber materials is experiencing a real boom throughout the world .The USA is considered to be a leader, where 80% of the bridges are made of timber or materials based on it. In Russia timber bridge construction has been stagnating for the last 50 years, although there is a need for these bridges. Timber structures could solve many problems with Russian roads, especially in remote areas. Timber structures are widely considered to be outdated, so they cannot meet current requirements of load capacity and durability, also they are vulnerable to atmospheric influences, etc. But foreign experience proves the contrary. The article is devoted to the implementation of new plank-nailed spans that meet current requirements of load capacity, reliability and durability.Materials and methods. The authors suggest and describe a new span structure. The span consists of planktimber- nailed-dowel blocks and a reinforced concrete slab generating a composite action. Some special crested shear connectors are suggested as combining elements. The top part works as flexible shear connectors in a reinforced concrete slab. The bottom part works as dowels with steel joints and timbers structures. The investigation of the stress-strain state of the structure has been completed within “compound beam” theory.Results. The application of the cast-in-place reinforced concrete slab allows to protect supporting timber structures against atmospheric influences, dirt, cracking from the sun rays, radiation and provides at least 50-year durability. The timber preservation provides a specified service life. The application of suggested connection with composite action between a reinforced concrete slab and supporting timber structures increases effectiveness of the composite timber concrete structure compared to steel and reinforced concrete structures. Trans-Baikal territory, Irkutsk and Arkhangelsk Regions, Khabarovsk Territory, the Republics of Sakha (Yakutia), Buriatia, Karelia are in the greatest need of the timber concrete composite spans, because they have a lot of forest resources and old timber bridges that are still in service.

Dimension and Frequency Profiles of Concrete Highway Bridges in New Madrid Region of Southeastern Missouri

1997 ◽  
Vol 1594 (1) ◽  
pp. 84-93 ◽  
Author(s):  
Ralph Alan Dusseau
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slab ◽  
Highway Bridges ◽  
Ambient Vibration ◽  
Earthquake Hazards ◽  
Empirical Formulas ◽  
Reinforced Concrete Slab ◽  
Box Girder ◽  
Bridge Spans ◽  
New Madrid

The results of a study funded by the U.S. Geological Survey as part of the National Earthquake Hazards Reduction Program are presented. The first objective of this study was the development of a database for all 211 highway bridges along I-55 in the New Madrid region of southeastern Missouri. Profiles for five key dimension parameters (which are stored in the database) were developed, and the results for concrete highway bridges are presented. The second objective was to perform field ambient vibration analyses on 25 typical highway bridge spans along the I-55 corridor to determine the fundamental vertical and lateral frequencies of the bridge spans measured. These 25 spans included six reinforced concrete slab spans and two reinforced concrete box-girder spans. The third objective was to use these bridge frequency results in conjunction with the dimension parameters stored in the database to develop empirical formulas for estimating bridge fundamental natural frequencies. These formulas were applied to all 211 Interstate highway bridges in southeastern Missouri. Profiles for both fundamental vertical and lateral frequencies were then developed, and the results for concrete highway bridges are presented.

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