scholarly journals Determination of features of composite steel and concrete slab behavior under fire condition

2021 ◽  
Vol 6 (7 (114)) ◽  
Author(s):  
Valeriia Nekora ◽  
Stanislav Sidnei ◽  
Taras Shnal ◽  
Olga Nekora ◽  
Iryna Dankevych ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Temperature Distribution ◽  
Fire Resistance ◽  
Temperature Regime ◽  
Strain State ◽  
Concrete Slabs ◽  
Standard Temperature ◽  
Steel Reinforced Concrete ◽  
Steel Sheets ◽  
Reinforced Concrete Slabs

Methods for calculating the fire resistance of steel-reinforced concrete slabs made using profiled steel sheets under the influence of a standard temperature regime for more than 120 minutes are considered and analyzed. Research has been carried out to determine the heating parameters and the stress-strain state of steel-reinforced concrete slabs made using profiled steel sheets under fire conditions for more than 120 minutes. The results of this study allow to obtain indicators of temperature distribution for assessing the fire resistance of such structures for fire resistance classes above REI 120. Accordingly, the results obtained are a scientific basis for improving the existing method for calculating the fire resistance of steel-reinforced concrete slabs made using profiled steel sheets. The temperature distribution in the cross-section of structures was obtained using a general theoretical approach to solving the problem of heat conduction using the finite element method. Using the obtained temperature distributions, the parameters of the stress-strain state were determined based on the method of limiting states. To carry out the calculations, appropriate mathematical models were created that describe the effect of the standard temperature regime of a fire, to determine the temperature distribution at every minute in the sections of steel-reinforced concrete slabs with profiled steel sheets. A method is proposed for dividing the section into zones to take into account the decrease in the indicators of the mechanical properties of concrete and steel. A simplified method for the design assessment of steel-reinforced concrete slabs made using profiled steel sheets is proposed, which is consistent with the current EU standards and can be effectively used to analyze their fire resistance when establishing their compliance with the fire resistance class REI 120 and higher.

Influence of the Fire Temperature Regime on the Fire-Retardant Ability of Reinforced-Concrete Floors Coating

2020 ◽  
Vol 1006 ◽  
pp. 87-92
Author(s):  
Andrii Kovalov ◽  
Yurii Otrosh ◽  
Oleg Semkiv ◽  
Volodymyr Konoval ◽  
Oleksandr Chernenko
Keyword(s):  
Reinforced Concrete ◽  
Fire Resistance ◽  
Temperature Regime ◽  
Fire Retardant ◽  
Protective Layer ◽  
Fire Regimes ◽  
Hollow Core ◽  
Standard Temperature ◽  
Concrete Floor

In the paper, the tests have been analysed for fire-resistant quality of the hollow-core reinforced-concrete floors with fire-retardant plaster covering under standard temperature regime of the fire. Using the methodology for determining the characteristics of fire-retardant coatings ability for reinforced-concrete floors, the dependences have been obtained of the fire-retardant coating thickness from the concrete protective layer of a hollow-core reinforced-concrete floor for a fire resistance limit of 180 minutes with a temperature regime of hydrocarbon fire and a tunnel curve according to the Netherlands standards (RWS). It has been concluded about the minimum required thickness of the studied fire-retardant coating to provide the required fire resistance limit of a hollow-core reinforced-concrete floor under the indicated fire regimes.

scholarly journals Investigation on Structural Behavior of Bamboo Reinforced Concrete Slabs under Concentrated Load

2021 ◽  
Vol 50 (1) ◽  
pp. 227-238
Author(s):  
Yanuar Haryanto ◽  
Nanang Gunawan Wariyatno ◽  
Hsuan-Teh Hu ◽  
Ay Lie Han ◽  
Banu Ardi Hidayat
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slab ◽  
Absorption Capacity ◽  
Concrete Slabs ◽  
Structural Behaviour ◽  
Reinforced Concrete Slab ◽  
Concentrated Load ◽  
Steel Reinforced Concrete ◽  
Reinforced Concrete Slabs ◽  
Cracking Pattern

Reinforced concrete is perhaps the most widely used building material in the world. However, the materials used for reinforcement of concrete i.e. steel is quite expensive and scarcely available in the developing world. As a result, bamboo is considered to be a cheaper replacement with high tensile strength. This research investigated the structural behaviour of bamboo-reinforced concrete slabs used for footplate foundation subjected to concentrated load. For this purpose, four different reinforced concrete slab panels were developed and analyzed. The influence of replacing steel with bamboo for the reinforcement of concrete slabs on their structural behaviour was assessed by determining the load-deflection characteristics, the ultimate load, the stiffness, the ductility, the cracking pattern, and the energy absorption capacity. The results showed that in comparison to steel reinforced concrete slabs, the strength of 82% can be acquired by the bamboo reinforced slabs. Furthermore, ductility demonstrated by the two types of specimens was almost equivalent i.e. up to 93%. Those indicated that the structural behaviour demonstrated by bamboo reinforced slabs is quite comparable to that of steel reinforced concrete slabs. Therefore, bamboo can prove to be a promising substitute for steel in concrete reinforcement. Future studies may further examine this opportunity.

scholarly journals Experimental research of punching shear mechanism of reinforcing concrete slab

2019 ◽  
Vol 97 ◽  
pp. 04032
Author(s):  
Nikolay Trekin ◽  
Dmitrii Pekin
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Experimental Research ◽  
Strain State ◽  
Concrete Slab ◽  
Punching Shear ◽  
Concrete Slabs ◽  
Stress Strain ◽  
Stress Strain State ◽  
Reinforced Concrete Slabs

The analysis of various regulatory methods for calculating reinforced concrete slabs for pushing and comparing with experiment results is made. The tested sample, measuring equipment and test bench are described. Sizes and materials for experimental prototype were chosen by existing beamless and capless slabs of monolithic reinforced concrete superstructures with column grid from 8×8 to 9×9 m. Experimental research results of reinforcing concrete plate structure are presented for study purpose of stress-strain state when punching shear collapse occurring. Various aspects and observations obtained during the test are given. The comparison of the tested slab fragment with the complete response of slab structure is performed. Analysis of tested sample stress-strain state and punching bearing capacity calculations results in according to existing regular standards were made. Main criterias of punching shear collapse were determined and new procedure for punching calculation of RC concrete slabs was offered basing on significantly new approach in punching bearing capacity defining.

Behavior of Two-way RC Slabs Combination Strengthened with CFRP Strips and Steel Sheets

2014 ◽  
Vol 501-504 ◽  
pp. 1048-1052 ◽  
Author(s):  
Xiao Jin Li ◽  
Yi Yan Lu ◽  
Na Li
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slab ◽  
Concrete Slabs ◽  
Test Results ◽  
Reinforced Concrete Slab ◽  
Steel Sheets ◽  
Reinforced Concrete Slabs ◽  
Rc Slab ◽  
Rc Slabs ◽  
Strengthening Technique

A total of four two-way reinforced concrete slabs strengthened with three methods were tested. The four test specimens were one unstrengthened reinforced concrete slab (control), one slab strengthened with CFRP strips, one slab strengthened with steel sheets, and one slab strengthened with an innovative method of applying CFRP strips and steel sheets combination bonding to the tension face of the slab. The test results show the CFRP-Steel combination strengthened technique is a rapid and effective strengthening technique for two-way RC slab. The increase in ultimate capacities of CFRP-Steel combination strengthened slab is 221.1% over the control slab, 84.4% over the CFRP-strengthened slab, and 45.2% over the steel-strengthened slab. In addition, the CFRP-Steel combination strengthened slab exhibited superior ductility than the CFRP-strengthened slab.

Deformation of Steel-Reinforced Concrete Round Thin Slabs Taking into Account the Compliance of the Support Contour

2021 ◽  
Vol 887 ◽  
pp. 680-690
Author(s):  
Kh.S. Razzokov
Keyword(s):  
Reinforced Concrete ◽  
Stress State ◽  
Strain State ◽  
Experimental Studies ◽  
Concrete Slabs ◽  
Governing Equations ◽  
Short Term ◽  
Steel Reinforced Concrete ◽  
Normalized Parameters

The paper presents the governing equations of bending of nonlinearly deformable, axisymmetrically loaded round, thin reinforced concrete and steel concrete slabs, taking into account the work of a non-deformable and pliable support contour. Based on the results of theoretical and experimental studies, the stress-strain state of reinforced concrete and steel-concrete slabs under short-term and long-term loadings was estimated. The nature of stress state is revealed in the stages of cracking and destruction of plates. The work of the slabs in the field of elastic, elastoplastic and plastic stages of work is estimated. Using the method of limiting equilibrium, a method for calculating steel-concrete slabs for strength with normalized parameters.

scholarly journals The effect of cracks on the bearing capacity of reinforced concrete slabs

2019 ◽  
Vol 97 ◽  
pp. 03001
Author(s):  
Vladimir Agapov
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Strain State ◽  
Concrete Slab ◽  
Physical Nonlinearity ◽  
Concrete Slabs ◽  
The Finite Element Method ◽  
Reinforced Concrete Slab ◽  
Reinforced Concrete Slabs ◽  
Composite Fabrics

Cracks occur in reinforced concrete slabs for two reasons - due to increased operational loads and due to manufacturing and installation defects. When cracks are detected, the question arises about the residual bearing capacity of the slab and the need of its strengthening. To solve this problem by calculation, it is necessary to take into account physical nonlinearity. An algorithm for the calculation by the finite element method is proposed. The main feature of the algorithm is the use of multilayered finite elements, which allows modeling the cracks by specifying the corresponding material characteristics of those layers which the crack passes through. A method for determining the bearing capacity of a slab with cracks after its reinforcement with composite fabrics is also considered. An example of the study of the stress-strain state of a reinforced concrete slab with cracks by the proposed method is given. The implementation of the algorithm in the PRINS program is described and the possibility of using this program for solving practical problems is discussed.

Sign in / Sign up

Export Citation Format

Share Document