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The purpose of this study is to inspect the corrosion inhibition of API N80 steel pipelines in uninhibited solution and inhibited with a synthesized surfactant compound [N-(3-(dimethyl octyl ammonio) propyl) palmitamide bromide] (DMDPP), which is prepared through a simple and applicable method.

Weight loss was inspected at five different temperatures of 25°C, 30°C, 40°C, 50°C and 60°C Potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and electrochemical frequency modulation were used at room temperature. Density functional theory was used to study the relation between the molecular structure and inhibition theoretically.

Adsorption of the prepared DMDPP fits the Langmuir isotherm model. The inhibition efficiency of the prepared DMDPP amphipathic inhibitor is directly proportional to temperature increase. Polarization results reveal that the investigated DMDPP amphipathic compound behaves as a mixed-type inhibitor. EIS spectra produced one individual capacitive loop.

The originality is the preparation of cationic surfactants through a simple method, which can be used as corrosion inhibitors in oil production. The synthesized inhibitors were prepared from low-price materials. The work studied the behavior of the synthesized surfactants in inhibiting the corrosion of the steel in an acidic medium. Electrochemical and theoretical studies were presented, besides gravimetric and surface examination.

Introduction From the range of engineering materials, steel finds wide application in the building construction industry. The majority of steel used is for structural purposes but thinner gauge coil and sheet products in the form of coated mild steel or stainless steel are increasingly used for cladding and roofing.

The main purpose of this study was to evaluate the tensile strengths of JIS G3549 super high-strength steel strand wire ropes (1,570 MPa-class high-carbon steels) and wire rope open swaged socket connections at fire and post fire.

Steady-state tests from ambient temperature (20 °C) to 800 °C, transient-state tests under the allowable design tensile force and tensile tests in an ambient temperature environment after heating (heating temperatures of 200–800 °C) were conducted.

The tensile strengths of the wire rope and end-connection specimens at both fire and post fire were obtained. The steel wire rope specimens possessed larger reduction factors than general hot-rolled mild steels (JIS SS400) and high-strength steel bolts (JIS F10T). The end-connection specimens with sufficient socket lengths exhibited ductile fracture of the wire rope part at both fire and post fire; however, those with short socket lengths experienced a pull-out fracture at the socket.

The fundamental and important tensile test results of the super high-strength steel strand wire ropes (1,570 MPa-class high-carbon steels) and wire rope open swaged socket connections were accumulated at fire and post fire, and the fracture modes were clarified. The obtained test results contribute to fire resistance performance-based design of cable steel structures at fire and fire-damage investigations to consider their reusability post fire.

This paper aims to investigate the fire performance of composite beams when considering the hogging moment resistance of the fin-plate beam-to-girder joints including the effect of continuity of reinforcements.

Experiments on composite beams with fin-plate joints protected only at the beam ends are conducted. The test parameter is the specification of reinforcement, which affects the rotational restraint of the beam ends. In addition, a simple method for predicting the failure time of the beam using an evaluation model based on the bending moment resistance of the beam considering the hogging moment resistance of the fin-plate joint and the reinforcement is also presented.

The test results indicate that the failure time of the beam is extended by the hogging moment resistance of the joints. This is particularly noticeable when using a reinforcing bar with a large plastic deformation capability. The predicted failure times based on the evaluation method corresponded well with the test results.

Recent studies have proposed large deformation analysis methods using FEM that can be used for fire-resistant design of beams including joints, but these cannot always be applicable in practice due to the cost and its complexity. Our method can consider the hogging moment resistance of the joint and the temperature distribution in the axial direction using a simple method without requirement of FEM.

This study aims to analyze and discuss the key design assumptions needed for design of car parks in steel, to highlight the impact that the increased fire loads introduced by modern cars and changes in the fire dynamics have on the design, such as fire spread leading to non-localized fires.

In particular, a reliable fire load density to be used for structural design of car park structures is assessed, based on investigations of the fire loads of modern cars. Based on knowledge of fire load and fire performance of cars, the consequences on the fire safety design of steel structures are presented.

Design recommendation about fire load density and fire protection of common steel profiles are given. Finally, the proposed design is compared with a design practice that has been applied in many instances for car parks constructed with unprotected steel, and recommendations for a reliable design process are provided.

Numerous car park buildings have recently been designed of steel structures without passive or active fire protection. The key assumptions that makes possible such design are local fire scenarios, outdated values of the car fire load and utilization of the ultimate steel strength. This paper identifies the shortcomings of such key assumptions, indicating the need for revisiting the methods and possibly even checking the analyses carried out for some already-built car parks.

This paper aims to facilitate verification of computer modelling techniques for complex structures exposed to fire and to test the effect of some steel beams being left unprotected.

This paper describes a fire test conducted on a large-scale structure representing four corner bays of a typical multi-storey steel-frame office building.

A new and unexpected mode of damage occurred.

The test results indicate that an alternate reinforcement detail should be used in combination with unprotected beams.

This paper aims to investigate the predicted temperature behaviour of the protected cellular steel beam (CSB) with circular web openings at elevated temperature through finite element simulation.

Temperature development along the CSB were analysed and used for parametric investigation. In addition, this research paper investigates the novelty application of various intumescent coating thicknesses covering the whole CSB to cut down the temperature development along the beam section.

From the simulation outcomes, it shows that intumescent coating has a significant effect in reducing the temperature development along the CSB section. Thicker intumescent coating contributes to a higher temperature drop at the bottom tee section than the upper tee section.

The use of structural CSB has gained popularity among engineers and architects. This type of beam allows serviceability ducts and pipes to pass through the main steel web section under the flooring system, thus providing larger headroom for designers. Nevertheless, in any structural steel building, it is highly risky for CSB to be exposed to fire hazard if it were triggered accidentally. To mitigate and reduce fire exposure risk which might compromise the strength and stiffness of CSB, a passive fire protection is proposed to minimise the risk. One of the common passive fire protection materials used for steel beam section is intumescent coating. Intumescent coating is by far the cheapest solution to protect CSB as compared to other passive fire protection system. Intumescent coating can absorb some portion of heat exposure which subsequently translates a lower temperature development along the CSB section.

Based on the known positive effects of conventional hot-dip galvanizing under fire exposure and indicative results on zinc–aluminum coatings from smallscale tests, a series of tests were conducted on zinc-5% aluminum galvanized test specimens under fire loads to verify the previous positive findings under largescale boundary conditions.

The emissivity of zinc-5% aluminum galvanized surfaces applied to steel specimens was determined experimentally under real fire loads and laboratory thermal loads in accordance with the normative specifications of the standard fire curve. Both large and smallscale specimens were used in this study. The steel grade and surface conditions of the specimens were varied for both test scenarios.

Largescale tests on specimens with typical steel construction dimensions under fire loads showed that the surface emissivity of zinc-5% aluminum galvanized steel was significantly lower than that of the conventionally galvanized steel. Only minor influences from the weathering of the specimens and steel chemistry were observed. These results agree well with those obtained from smallscale tests. The design values of zinc-5% aluminum melt (Zn5Al) required for the structural fire design were proposed based on the obtained results.

The novel tests presented in this study are the first ones to study the behavior of zinc-5% aluminum galvanized largescale steel construction components under the influence of real fire exposure and their positive effect on the emissivity of steel components galvanized by this method. The results provide valuable insights and information on the behavior in the case of fire and the associated savings potential for steel construction.

The aim of this paper is to determine the thermal conductivity of a protective layer of alkali-activated cement and the possibility of performing fire protection with fireclay sand and Lightweight mortar. Unprotected steel structures have generally low fire resistance and require surface protection. The design of passive protection of a steel element must consider the service life of the structure and the possible need to replace the fire protection layer. Currently, conventional passive protection options include intumescent coatings, which are subject to frequent inspection and renewal, gypsum and cement-based fire coatings and gypsum and cement board fire protection.

Alkali-activated cements provide an alternative to traditional Portland clinker-based materials for specific areas. This paper presents the properties of hybrid cement, its manufacturability for conventional mortars and the development of passive fire protection. Fire experiments were conducted with mortar with alkali-activated and fireclay sand and lightweight mortar with alkali-activated cement and expanded perlite. Fire experiment FE modelling.

The temperatures of the protected steel and the formation of cracks in the protective layer were investigated. Based on the experiments, the thermal conductivities of the two protective layers were determined. Conclusions are presented on the applicability of alkaline-activated cement mortars and the possibilities of applicability for the protection of steel structures. The functionality of the passive fire layer was confirmed and the strengths of the mortar used were determined. The use of alkali-activated cements was shown to be a suitable option for sustainable passive fire protection of steel structures.

Eco-friendly fire protection based on hybrid alkali-activated cement of steel members.

The primary purpose of this research was to expand the knowledge base regarding the behavior of steel columns during exposure to fire. This paper presents the numerical study of the effect of heat on the performance of parking steel column in a seven-story steel building under cyclic loading.

In this research, the forces and deformations developed during a fire are estimated by using detailed 3D finite-element models. The analyses are in the form of a coupled thermo-mechanical analysis in two types of loading: concurrent loading (fire and cyclic loading) and non-concurrent loading (first fire and then cyclically), and the analyses have been conducted in both states of the fire loading with cooling and without cooling using the ABAQUS software. Further, it was investigated whether, during the fire loading, the specimen was protected by a 3-cm-thick concrete coating and how much it changes the seismic performance. After verification of the specimen with the experimental test results, the column model was investigated under different loading conditions.

The result of analyses indicates that the effect of thermal damage on the performance of steel columns, when cooling is happening late, is more than the state in which cooling occurs immediately after the fire. In this paper, thermal–seismic performance of parking steel columns has been specified and the effect of the fire damage has been investigated for the protected steel by concrete coating and to the non-protected steel, under both cooling and non-cooling states.

This study led to recommendations based on the findings and suggestions for additional work to support performance-based fire engineering. It is clear that predicting force and deformation on steel column during fire is complex and it is affected by many variables. Here in this paper, those variables are examined and proper results have been achieved.