scholarly journals The influence of depth of tensile concrete deterioration on the load bearing strength and deflections of corrosion-damaged floor slabs

2018 ◽  
Vol 251 ◽  
pp. 02012
Author(s):  
Ashot Tamrazyan ◽  
Arman Minasyan
Keyword(s):  
Experimental Investigation ◽  
Reinforced Concrete ◽  
Concrete Slabs ◽  
Load Bearing ◽  
Concrete Floor ◽  
Bearing Strength ◽  
Concrete Deterioration ◽  
Reinforced Concrete Slabs ◽  
Floor Slabs ◽  
Tensile Zone

The paper considers the change of load-bearing strength and deflections of corrosion-damaged precast reinforced concrete floor slabs in the conditions of cyclic freezing-thawing in full-scale climatic conditions. The aim of the study is to determine the influence of the depth of tensile concrete deterioration on the change in load-bearing strength and deflections. Corrosion-damaged precast reinforced concrete floor slabs were selected and experimental investigation was performed. Based on the results of the study, the influence of the depth of deterioration of tensile zone of concrete on the load-bearing strength and deflections of structures was determined. At the same time, as the loads increase, deflections increase and the height of the compressive zone decreases. In the experimental investigation, changes of the load-bearing strength and deflections of precast reinforced concrete slabs were determined, depending on the depth of tensile concrete deterioration. The performed studies allow us to estimate the load-bearing strength and deflection values of corrosion-damaged reinforced concrete slabs depending on the relative value of the concrete deterioration in the tensile zone without performing additional experiments and calculations.

THE CHANGE IN THE BEARING CAPACITY IS CORROSIVE-DAMAGED FLOOR SLABS DEPENDING ON THTHE CHANGE IN THE BEARING CAPACITY IS CORROSIVE-DAMAGED FLOOR SLABS DEPENDING ON THE DEPTH OF DAMAGE TO THE STRETCHED ZONE CONCRETEE DEPTH OF DAMAGE TO THE STRETCHED ZONE CONCRETE

2021 ◽  
Vol 295 (2) ◽  
pp. 27-31
Author(s):  
A.A. Minasyan ◽  
Keyword(s):  
Bearing Capacity ◽  
Bending Moment ◽  
Concrete Slabs ◽  
Sectional Area ◽  
Load Bearing ◽  
Bearing Strength ◽  
Concrete Deterioration ◽  
Reinforced Concrete Slabs ◽  
Floor Slabs ◽  
Stress Diagram

In this work, the influence of the depth of tensile concrete deterioration on the load-bearing strength and deflections of precast reinforced concrete slabs were determined experimentally. The momenta determination and measurement of deflections was carried out by loading the structure stepwise. Analysis of the results of the study indicated the following: as the plates are damaged, with the increase in the height of tensile concrete deterioration, the stress diagram gets gradually filled in the compressive sectional area and its height decreases, which can lead to the destruction of the structure. At the same time, the shear and bending moment diagram of sectional deformation gets curved. As the slab deflections increase, its load-bearing strength decreases.

scholarly journals Modeling of joint work of steel beam constructions with reinforced concrete ribbed floor slabs

2021 ◽  
pp. 44-57
Author(s):  
Yevhen Dmytrenko
Keyword(s):  
Reinforced Concrete ◽  
Cross Section ◽  
Precast Concrete ◽  
Concrete Slabs ◽  
Effective Width ◽  
Joint Work ◽  
Load Bearing ◽  
Reinforced Concrete Slabs ◽  
Industrial Buildings ◽  
Floor Slabs

Traditional methods of calculation of beam constructions of floors and coverings of industrial buildings assume their consideration when calculating separately from the frame structures, in particular, reinforced concrete slabs, without taking into account their joint work, which leads to a significant margin of safety. Today in Ukraine there is a significant number of industrial buildings and structures that need strengthening and reconstruction. In this regard, of particular importance are studies of the actual load-bearing capacity of the frames of single-storey and multi-storey industrial buildings, and both in the reconstruction and in new construction, the results of which will significantly reduce costs and more rationally design structures. At the same time, one of the most relevant areas is the study of the joint work of metal load-bearing structures with prefabricated reinforced concrete structures of rigid disks of coatings and floors in their calculation.           Moreover, in the national building codes, as well as in the educational and methodological literature, the calculation methods of taking into account the joint work of such constructions are not fully covered. The purpose of this work is to estimate the reduction of mass of the metal beam structure in its calculation in bending, taking into account the joint work with the rigid disk of the floor consist of precast concrete. As part of the study, the calculation of the floor beam according to the traditional calculation scheme - without taking into account the joint work with the floor slab, the calculation of its cross-section taking into account the joint work with floor slabs and experimental numerical study of the floor by the finite element method. Modeling of the floor fragment was performed in the software packages "SCAD Office" and "LIRA CAD 2019". Numerical research is aimed at verifying the feasibility of using the calculation methodology of DBN B.2.6-98-2009 to determine the effective width of the shelf when calculating the T-sections for prefabricated reinforced concrete slabs, which are included in the joint work with the floor beams. A comparative analysis of the obtained cross-section of the beam with the beam which was previously calculated by the traditional method of calculation  in stresses in the most dangerous cross section and the total mass of the beams. According to the results of the analysis, the correctness of the application of the above normative method for determining the effective width of the shelf of T-bending reinforced concrete elements was confirmed.

scholarly journals EVALUATING THE EFFECTIVE DESIGN OF REINFORCED CONCRETE FLOOR SLABS IN CIVIL WORKS IN TRA CU DISTRICT – TRA VINH PROVINCE

2020 ◽  
Vol 1 (35) ◽  
pp. 51-61
Author(s):  
Cong Thanh Nguyen ◽  
Nhung Hong Tu
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slabs ◽  
Slab Thickness ◽  
Design Technique ◽  
Concrete Floor ◽  
Reinforced Concrete Slabs ◽  
Floor Slabs ◽  
Design Documents ◽  
Engineering Projects ◽  
Effective Design

This study was conducted to determine the effectiveness of the design of reinforced concrete slabs of several civil engineering projects in Tra Cu district – Tra Vinh province. Utilizing the design documents of 6 projects, these slabs were redesigned based on TCVN 5574 – 2018. The design results were compared with those provided in the design documents. The results show that most of the design in the provided documents was either greater than or equal to the end design studied: the slab thickness is from 0% - 20%, the steel percentage of the slabs are from 0% - 63,3%, and the concrete quantity is from 0% - 20%. In conclusion, it is recommended for engineers to select an optimal slab design technique in order to reduce dead loads, to provide a reasonablesteel percentage and still being capable of carrying loads, which will result in an effective design for the project.

scholarly journals Strengthening Klein’s floor slabs with the use of current norms

2015 ◽  
Vol 14 (4) ◽  
pp. 197-205
Author(s):  
Marcin Górecki ◽  
Dominika Franczak-Balmas
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slabs ◽  
Steel Beams ◽  
Structural Members ◽  
Existing Buildings ◽  
Concrete Floor ◽  
Reinforced Concrete Slabs ◽  
Floor Slabs

The paper presents the effectivity of using the steel-concrete floor slabs in existing buildings. Steel-concrete slabs described in this paper consist of old steel beams which are main structural members of the floor slabs and reinforced concrete slabs which are new elements of the floor slabs. Beams and reinforced concrete slabs are connected with connectors. The computational example which shows the efficiency of utilizing the steel-concrete floor slabs with the use of current norms has been presented in the paper.

scholarly journals Effect of the Geometrical Constraints to the Wenner Four-Point Electrical Resistivity Test of Reinforced Concrete Slabs

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4622
Author(s):  
Kevin Paolo V. Robles ◽  
Jurng-Jae Yee ◽  
Seong-Hoon Kee
Keyword(s):  
Experimental Investigation ◽  
Electrical Resistivity ◽  
Reinforced Concrete ◽  
Concrete Slab ◽  
Plain Concrete ◽  
Electrode Spacing ◽  
Concrete Slabs ◽  
Reinforced Concrete Slabs ◽  
Spacing Ratio ◽  
Geometrical Constraints

The main objectives of this study are to evaluate the effect of geometrical constraints of plain concrete and reinforced concrete slabs on the Wenner four-point concrete electrical resistivity (ER) test through numerical and experimental investigation and to propose measurement recommendations for laboratory and field specimens. First, a series of numerical simulations was performed using a 3D finite element model to investigate the effects of geometrical constraints (the dimension of concrete slabs, the electrode spacing and configuration, and the distance of the electrode to the edges of concrete slabs) on ER measurements of concrete. Next, a reinforced concrete slab specimen (1500 mm (width) by 1500 mm (length) by 300 mm (thickness)) was used for experimental investigation and validation of the numerical simulation results. Based on the analytical and experimental results, it is concluded that measured ER values of regularly shaped concrete elements are strongly dependent on the distance-to-spacing ratio of ER probes (i.e., distance of the electrode in ER probes to the edges and/or the bottom of the concrete slabs normalized by the electrode spacing). For the plain concrete, it is inferred that the thickness of the concrete member should be at least three times the electrode spacing. In addition, the distance should be more than twice the electrode spacing to make the edge effect almost negligible. It is observed that the findings from the plain concrete are also valid for the reinforced concrete. However, for the reinforced concrete, the ER values are also affected by the presence of reinforcing steel and saturation of concrete, which could cause disruptions in ER measurements

Flexural behavior of sustainable reactive powder concrete bubbled slab flooring elements

2017 ◽  
Vol 3 (2) ◽  
pp. 81 ◽  
Author(s):  
Ashraf Abdulhadi Alfeehan ◽  
Hassan Issa Abdulkareem ◽  
Shahad Hameed Mutashar
Keyword(s):  
Reinforced Concrete ◽  
Ultimate Load ◽  
Steel Fibers ◽  
Flexural Behavior ◽  
Reactive Powder Concrete ◽  
Concrete Slabs ◽  
Concrete Floor ◽  
Reinforced Concrete Slabs ◽  
Reactive Powder ◽  
Floor System

Voided slabs are reinforced concrete slabs in which voids allow to reduce the amount of concrete. The bubbled deck slab is a new and sustainable biaxial floor system to be used as a self-supporting concrete floor. The use of voided slabs leads to decrease the consumption of materials and improve the insulation properties for enhancing the objectives of sustainability. This study presents an investigation into the flexural behavior of sustainable Reactive Powder Concrete RPC bubbled slab flooring elements. Six one-way slabs were cast and tested up to the failure. The adopted variables in this study are: the volumetric ratio of steel fibers, type of slab; bubbled or solid, placing of reinforcement and thickness of slab. The effect of each variable on the ultimate load, deflection and strain has been discussed. The results show that increasing the percent of steel fibers from 1% to 2% in solid and bubbled slabs decreases the deflection by (18.75%) and (50%) respectively. As well as, the deflection increases by (41%) for bubbled slab compared to the solid slab. The slabs reinforced with top and bottom steel meshes show less deflection than slabs reinforced by only bottom steel mesh.

EXPERIMENTAL STUDY OF PUNCHING SHEAR OF UNBONDED POST-TENSIONED REINFORCED CONCRETE SLABS

2020 ◽  
pp. 6-14
Author(s):  
T.R. Barkaya ◽  
◽  
A.V. Gavrilenko ◽  
V.V. Fedorov ◽  
P.V. Kulyaev ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Shear Test ◽  
Punching Shear ◽  
Concrete Slabs ◽  
Reinforced Concrete Slabs ◽  
Shear Loads ◽  
Floor Slabs ◽  
Geometrical Dimensions ◽  
Positive Effect ◽  
Post Tensioned

In this paper there are results of a punching shear test of slab samples, which were modeling post-tensioned reinforced concrete floor slabs when they are punched by columns. Geometrical dimensions of slab samples and properties of used materials are listed as well. There were 4 series of samples which differed to each other by level of prestress. Load have been applied through stamps of several types, which have allowed to research different positions of tensioned reinforcement relatively to the punching pyramid. Obtained results are discussed. Recommendations, which compliance may allow to obtain positive effect in ultimate punching shear loads for unbonded post-tensioned slabs are given.

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