scholarly journals Deflection Analysis of Layered Slabs with Plastic Inserts

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6050
Author(s):  
Juozas Masėnas ◽  
Remigijus Šalna ◽  
Linas Juknevičius ◽  
Juozas Valivonis

The article deals with experimental and numerical research of the layered reinforced concrete slab with plastic inserts. The investigated layered reinforced concrete slab is made of prefabricated and monolithic reinforced concrete layers. Voids were formed in the plate with spherical plastic inserts. With reference to the built-up bars theory, the paper proposes an analytical method for calculating the deflection of the layered reinforced concrete structures in non-linear stage, when bond between layers is partially rigid. The article also focuses on the numerical simulation of the layered slab, compares the estimated theoretical values of deflection with the experimental values and assesses the shear stiffness of the bond of prefabricated and monolithic concrete layers for calculating the deflection of the reinforced concrete slab. Paper presents the parametric analysis of deflection dependence on shear stiffness and the width of the contact zone of the layers. It was established that proposed analytical method and numerical analysis properly characterise the behaviour of the slab. Calculation results were close to experimental data. Moreover, it was determined that performance of this type of slab is highly influenced by shear stiffness of the bond between the concrete layers. Analysis confirmed that slab fails when bond is damaged, and layers slip in the support zone.

Author(s):  
O. Efimov ◽  
L. Gimranov ◽  
A. Fattahova ◽  
M. Chekanin

Combined steel-reinforced concrete floors using profiled flooring are the most common solution in buildings with a steel frame. Flexible stops ensure the joint work of the frame and the flooring disks. Deformations of the combined flooring, and therefore of the frame in the horizontal plane, can occur due to the possible appearance of uneven force effects that cause a shift. At the same time, the magnitude of these deformations is influenced by both the level of force influences and the shear stiffness of the flooring disk, as well as the malleability of the flexible stops connecting the latter to the supporting frame. The paper proposes a method for determining the deformations of the flooring disk and the supporting frame from a horizontal load. The problem is considered in which a square floor slab is based on a contour on the crossbars of the frame, but its fixing with flexible stops is provided on two parallel sides. A formula for determining the movements of the frame from the horizontal load is proposed. The displacement of the flooring disk is analytically determined, it is noted how the malleability of flexible stops affects the determination of the final result. Using the example of a numerical experiment, the possibility of using the proposed method is demonstrated. The movement in the flooring disks will allow to assess the rigidity of the frame from horizontal loads without focusing on the deformation of each component of the steel-reinforced concrete slab. In addition, it will help to use materials and resources more efficiently by optimizing design solutions.


2022 ◽  
Vol 14 (0) ◽  
pp. 1-5
Author(s):  
Juozas Masėnas

In this article results of experimental and numerical analysis of precast – in situ reinforced concrete slab with plastic void formers are discussed. Slab is composed of precast and in situ concrete layers. Voids are formed inside the slab using spherical plastic void formers. Slab cracking pattern is determined by numerical analysis. Cracking pattern acquired by numerical analysis is compared to cracking pattern determined by experimental study. Shear stiffness in the bond between precast and in situ concrete layers was specified when numerical model was built.


Author(s):  
Ralph Alan Dusseau

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.


1985 ◽  
Vol 50 ◽  
Author(s):  
A. Atkinson ◽  
D. J. Goult ◽  
J. A. Hearne

AbstractA preliminary assessment of the long-term durability of concrete in a repository sited in clay is presented. The assessment is based on recorded experience of concrete structures and both field and laboratory studies. It is also supported by results of the examination of a concrete sample which had been buried in clay for 43 years.The enoineering lifetime of a 1 m thick reinforced concrete slab, with one face in contact with clay, and the way in which pH in the repository as a whole is likely to vary with time have both been estimated from available data. The estimates indicate that engineering lifetimes of about 103 years are expected (providing that sulphate resisting cement is used) and that pH is likely to remain above 10.5 for about 106 years.


2014 ◽  
Vol 606 ◽  
pp. 229-232 ◽  
Author(s):  
Petr Tej ◽  
Vítězslav Vacek ◽  
Jiří Kolísko ◽  
Jindřich Čech

The paper focuses on a computer nonlinear analysis of the formation and development of cracks in a concrete slab exposed to a uniform continuous load on the lower surface. The analysis is based on an actual example of the formation and development of cracks in a basement slab exposed to ground water buoyancy.


1999 ◽  
pp. 251-259
Author(s):  
Shigenori YUYAMA ◽  
Zhang-Wang LI ◽  
Takeshi TOMOKIYO ◽  
Masaru YOSHIZAWA ◽  
Taketo UOMOTO

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