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 Fire resistance evaluation of reinforced concrete floors with fire-retardant coating by calculation and experimental method

2018 ◽  
Vol 60 ◽  
pp. 00003 ◽  
Author(s):  
Andrii Kovalov ◽  
Yurii Otrosh ◽  
Olha Ostroverkh ◽  
Oleksandr Hrushovinchuk ◽  
Oleksandr Savchenko
Keyword(s):  
Reinforced Concrete ◽  
Experimental Method ◽  
Fire Resistance ◽  
Heat Conductivity ◽  
Mining Industry ◽  
Fire Retardant ◽  
Hollow Core ◽  
Resistance Evaluation ◽  
Concrete Floor ◽  
Direct Problems

With the help of a previously developed technique based on the solution of inverse and direct problems of heat conductivity, the fire resistance of a hollow-core reinforced concrete floor with “Neosprei” fire-retardant plaster coating was estimated. The thermal and physical characteristics, as well as characteristics of the fire-proof ability of “Neosprei” fire-retardant plaster coating, have been determined. The conclusion has been made on the effectiveness of this coating and on the boundaries of the fire-retardant coatings use to ensure the normed values of the fire resistance degree of hollow-core reinforced concrete floors, including in the mining industry.

Fire Protection of Steel and Reinforced Concrete Structures of Industrial Buildings and Structures

2021 ◽  
pp. 50-56
Author(s):  
V.I. Golovanov ◽  
◽  
A.V. Pekhotikov ◽  
V.V. Pavlov ◽  
◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Fire Resistance ◽  
Fire Protection ◽  
Temperature Regime ◽  
Fire Retardant ◽  
Steel Structures ◽  
Reinforced Concrete Structures ◽  
Building Structures ◽  
Industrial Buildings ◽  
Temperature Regimes

Variants of progressive solutions for the use of efficient fire protection means for steel and reinforced concrete structures of the industrial buildings and structures are considered for the purpose of increasing the actual fire resistance and ensuring the requirements of fire safety norms. Distinctive features of the temperature regimes in the initial phase of a real fire from a standard fire were established when assessing the fire resistance of building structures. It is proposed to use such standardized temperature regimes of fire for assessing the fire resistance of building structures, as standard — in the industrial buildings; temperature regime of hydrocarbons combustion — for oil and gas, petrochemical enterprises, offshore stationary platforms; tunnel temperature regime — in the road and railway tunnels. Considering the operating conditions and performance of work on fire protection, the degree of aggressiveness of the environment, the structural and methodological scheme was developed for selecting passive fire protection for steel structures. Recommendations are given on limiting the use of intumescent paints for load-bearing steel structures involved in the overall stability of buildings, with the required fire resistance limit of no more than 30 minutes. To calculate the temperature over the section of the structure during its heating, the dependences of the change in the coefficients of thermal conductivity and heat capacity of fire-retardant linings under fire were obtained. Experimental studies were conducted related to the fire resistance of reinforced concrete floor slabs and slabs with an external reinforcement system based on the carbon composite material with various types of fire-retardant materials. The issue of protecting the lining blocks of road and railway tunnels from brittle (explosive) destruction of concrete in a fire is considered. It is experimentally confirmed that the addition of polypropylene fibers to the concrete mixture replaces the use of fire protection for the tunnels enclosing structures.

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.

EVALUATION OF FIRE RESISTANCE OF FIRE PROTECTED STEEL STRUCTURES

2021 ◽  
pp. 149-158
Author(s):  
Andrii Kovalov ◽  
◽  
Yurii Otrosh ◽  
Vitalii Tomenko ◽  
Andrii Kondratiev ◽  
...  
Keyword(s):  
Numerical Modeling ◽  
Experimental Method ◽  
Fire Resistance ◽  
Fire Retardant ◽  
Steel Structures ◽  
Resistant Steel ◽  
Standard Temperature ◽  
Steel Columns ◽  
Steel Column ◽  
Fire Resistant Steel

Purpose. Evaluation of fire resistance of fire-resistant steel structures using the developed calculation and experimental method. Methods. Finite difference method, landfill fire test method, mathematical and computer modeling of non-stationary heat exchange processes, determination of thermophysical characteristics of fire-retardant coatings based on solving direct and inverse thermal conductivity problems. Results. Geometric, physical, computer models have been developed, with the help of which the fire resistance of fire-resistant steel structures has been evaluated by the calculation-experimental method. The adequacy of the developed method for assessing the fire resistance of fire-resistant steel structures in assessing the fire resistance of fire-resistant I-beam steel column has been checked. The analysis of tests on fire resistance of fire-resistant steel columns exposed to fire at the standard temperature of the fire without the load applied to them has been carried out. A computer model of the “steel column – reactive flame retardant coating” system has been built for numerical simulation of non-stationary heating of such a system. The fire resistance of fire-resistant steel columns of I-beam section without load applied to them has been evaluated using the calculation-experimental method. Verification of results of experimental research with results of numerical modeling has been carried out. Scientific novelty. The convergence of the results of experimental data on the duration of fire exposure at the standard temperature of the fire to reach the critical temperature of steel with the results of numerical simulations has been determined. Based on the comparison of the experimental results and numerical modeling, the adequacy of the developed model to the real processes that occur when heating fire-retardant steel columns without applying a load under fire conditions at a standard fire temperature has been confirmed. The efficiency of the proposed calculation and experimental method for assessing the fire resistance of fire-resistant steel structures has been confirmed. Practical significance. It consists in the implementation of the results on objects of different purposes in assessing the fire resistance of fire-resistant steel structures by evaluating the effectiveness of fire-retardant coatings of steel building structures.

Increase of Temperature and Fire Resistance for Reinforced-Concrete Structures by Surface Treatment with Protective Coating

2018 ◽  
Vol 788 ◽  
pp. 36-44
Author(s):  
Liudmyla Demydchuk ◽  
Dmytro Sapozhnyk
Keyword(s):  
Reinforced Concrete ◽  
Fire Resistance ◽  
Protective Coating ◽  
Concrete Structures ◽  
Fire Retardant ◽  
Reinforced Concrete Structures ◽  
Building Structures ◽  
Fire Tests ◽  
Normative Documents ◽  
Concrete Building

The normative documents of Ukraine (DBN V.1.1.7 ̶ 2016) [1] establish that the limit of fire resistance of reinforced-concrete building structures is determined by the calculation method or by fire tests, and shall be at least 45 minutes. Taking into account the modern construction technologies, namely, the reduction of the section of the main building reinforced-concrete structures, it is expedient to use fire-retardant coatings to provide the necessary fire resistance limit.

scholarly journals Parameters for simulation of the thermal state and fire-resistant quality of hollow-core floors used in the mining industry

2019 ◽  
Vol 123 ◽  
pp. 01022 ◽  
Author(s):  
Andrіі Kovalov ◽  
Volodymyr Konoval ◽  
Anastasiia Khmyrova ◽  
Kateryna Dudko
Keyword(s):  
Fire Resistance ◽  
Thermal State ◽  
Mining Industry ◽  
Literary Analysis ◽  
Building Structures ◽  
Hollow Core ◽  
Industrial Construction ◽  
Software Complex

The statistical data of the fire and technogenic safety in Ukrainian mines have been studied. A literary analysis has been made of advanced expertise in determining the fire resistance of building structures. It has been studied the thermal state and fire resistance of hollow-core floors using the fire tests and the calculated determination of the fire resistance degree of a structure based on a two-dimensional model of thermal conductivity and convective heat transfer implemented in the ANSYS R17.1 software complex. The fire test of hollow-core floor has been analysed and the use of a computational-experimental method is proposed to determine the parameters when simulating the thermal state and the fire resistance of both protected and unprotected hollow-core floors. A technique has been developed for simulating the thermal state and the fire resistance of hollow-core floors, which can be used in assessment of the fire resistance degree of reinforced concrete building structures both in industrial construction and in the mining industry.

Experimental Researches on Fire Resistance of CFS Shear Strengthened Reinforced Concrete Beams

2011 ◽  
Vol 335-336 ◽  
pp. 1186-1189
Author(s):  
He Fan ◽  
Jun Yu Liu ◽  
Bao Kuan Ning
Keyword(s):  
Reinforced Concrete ◽  
Fire Resistance ◽  
Failure Modes ◽  
Shear Failure ◽  
Fire Retardant ◽  
Reinforced Concrete Beams ◽  
Insulation Material ◽  
Rc Beams ◽  
Fire Resistance Rating ◽  
Resistance Rating

Fire-resistance performance experiments with static loading-fire are investigated about one carbon fiber sheet（CFS） shear strengthened and one without CFS strengthened reinforced concrete (RC) beams exposed to the ISO834 standard fire. Shear strengthened RC beams are wrapped with fire insulation material- thick painted fire retardant coatings. Relationship between measure points temperature, displacement and time are achieved. The results suggest that: the ratio of shear-span is the main factor to fire-resistance rating and failure modes of CFS shear strengthened RC beams in fire; shear-failure fire-resistance rating are increased by thickening fire insulation to shear strengthened RC beams; mid-span deflection of shear failure is approximate one half of bending failure when shear strengthened RC beams.

Fire Resistance of Reinforced Concrete Corrosion-Damaged Columns of the "Standard" Fire

2019 ◽  
Vol 828 ◽  
pp. 163-169
Author(s):  
Ashot Georgievich Tamrazyan ◽  
Micheal Sergeevich Mineev ◽  
Aishat Urasheva
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Fire Resistance ◽  
Protective Layer ◽  
Operating Conditions ◽  
Corrosive Environment ◽  
Reinforced Concrete Column ◽  
Cross Sectional ◽  
Standard Fire ◽  
The Cross

The article describes the features of the effect of corrosion of reinforcement on the bearing capacity of reinforced concrete columns in a "standard" fire. On the basis of the standard calculation method, the fire resistance of the column was estimated under a four-sided fire effect taking into account the different duration of the fire. The study examined the operation of the column in a corrosive environment, it was assumed that the initiation of corrosion of concrete and reinforcement will occur after 10 years of exploitation. It was found that the destruction of concrete protective layer 25 mm thick in a medium aggressive environment will occur after 25 years, and the diameter of the reinforcement during this period will decrease by 20%. To compare the results, a reinforced concrete column with a section of 400x400mm was calculated under the influence of a “standard” fire under normal operating conditions and taking into account work in a corrosive environment. The results of heat engineering calculations are presented, where the temperature changes in the reinforcement depending on the heating time and reduction of the protective layer thickness, as well as the change in the diameter of the reinforcement and its effect on the bearing capacity are shown. It has been established that reducing the cross-sectional area of the working reinforcement and reducing the cross-sectional dimensions of the column due to the occurring corrosion processes leads to a decrease in the fire resistance limit on the loss of bearing capacity by 58%.

scholarly journals EVALUATION OF FIRE-PROTECTIVE ABILITY OF NEWLY CREATED FIRE-PROTECTIVE COATINGS OF STEEL STRUCTURES

2021 ◽  
pp. 79-88
Author(s):  
A. Kovalov ◽  
◽  
Y. Otrosh ◽  
V. Tomenko ◽  
O. Vasylyev ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Fire Resistance ◽  
Fire Protection ◽  
Experimental Studies ◽  
Fire Retardant ◽  
Steel Structures ◽  
Steel Plates ◽  
Thermal Calculation ◽  
Thermophysical Characteristics ◽  
Standard Temperature

Abstract. The results of the development of fire-retardant substances based on domestic materials to increase the fire resistance of fire-retardant steel structures are presented. New compositions of fire-retardant substances on the basis of domestic materials capable of swelling are developed. A series of experimental studies to determine the heating temperature of fire-resistant steel structures. For this purpose, samples of reduced size in the form of a steel plate with a flame retardant applied to the heating surface were used. Fire tests of fire-retardant steel plates coated with the developed fire-retardant substance forming a coating on the protected surface, in the conditions of their tests on the standard temperature of the fire using the installation to determine the fire-retardant ability of fire-retardant coatings. The results of experimental determination of temperature from an unheated surface of steel plates with a fire-retardant covering in the conditions of fire influence at a standard temperature mode of a fire are analyzed. Based on the obtained data (temperature in the furnace and from the unheated surface of steel plates with fire protection system) the solution of the inverse problems of thermal conductivity found thermophysical characteristics of fire protection coating (thermal conductivity and specific volume), which can be used for thermal calculation heating of fire-retardant steel structures at arbitrary fire temperatures. The thermophysical characteristics of the formed fire-retardant coating are substantiated to find the characteristics of the fire-retardant ability of the newly created fire-retardant coating and to ensure the fire resistance of fire-retardant steel structures. The efficiency of the developed fire-retardant coating for protection of steel structures is proved.

Non-Standard Methods for Assessing the Quality of Intumescent Coatings

2021 ◽  
pp. 15-20
Author(s):  
A.V. Martynov ◽  
◽  
O.V. Popova ◽  
V.V. Grekov ◽  
◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fire Retardant ◽  
Protective Layer ◽  
Foam Formation ◽  
Building Structures ◽  
Limit Values ◽  
Standard Methods ◽  
Intumescent Coatings ◽  
Counterfeit Products

The main most frequently used structural materials are monolithic reinforced concrete, steel profiles and lightweight thin-walled building structures, which in case of fire at temperatures above 500 °C lose their mechanical properties, deform, and collapse. To protect the load-bearing structures from dangerous deformations for a certain time before the start of extinguishing a fire, various fire-retardant materials are used, among which thin-layer intumescent coatings occupy a special place. Serious problems with the quality of intumescent coatings are associated with the use by manufacturers of paint components (often counterfeit products of low quality) that do not correspond to those stated in the certificates. In these cases, the intumescent coating does not guarantee the formation of a high-quality protective layer of the coke foam in case of fire. Standard methods for assessing the quality of such coatings allow to assess appearance, thickness, and adhesion of the coating prior to coke foam formation. However, it is required to check directly on the object the additional non-standard parameters of the intumescent coatings: intumescence coefficient, appearance and strength of the coke foam. Ways are described related to the implementation of measuring the structural and mechanical properties of the coke foam: intumescence coefficient, penetration and shear-breakout strength. It is proposed to measure the strength characteristics of the coke foam by the penetrometry method on an original installation (analogue of a cone penetrometer). The proposed measurement method is simple, demonstrative and does not require expensive equipment. The dependence is revealed concerning the strength of the coke foam on its density, which is determined by the intumescence coefficient at all other things being equal. The higher the intumescence coefficient, the lower the density and strength of the coke foam. Therefore, high values of the intumescence coefficient do not guarantee the reliability of fire protection. It is recommended to set normatively limit values for the intumescence coefficient, which will differ for different compositions of the intumescent paints.

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