Latest trends for structural steel protection by using intumescent fire protective coatings: a review

Abstract

Intumescent coating (IC) is one of the famous protection systems for steel structures in the event of fire. Over the last few decades, ICs have been gaining much attention because they are applied on steel structure as fire protection. Upon exposure to flame, the coatings burn and swell, forming a heat shield called char. The formed char plays a critical role in protecting the steel substrate from the sudden rise in temperature which in return maintains the structural integrity of steel. In view of the importance of ICs, especially to the oil and gas sector, this paper reviews recent work on materials used for coatings and processing techniques for IC formation. The paper also gathers the latest information that focuses on ICs' main binders, flame retardant additives, and fillers. Finally, important issues in regard to durability and reliability of coatings in different environments are also highlighted.

Technical research and development

“…One of the main methods for increasing fire resistance of steel structures is the use of passive fire protection: materials and elements, that increase the time of maintaining load-bearing capacity of structure during fire [1]. Among the variety of fire-retardant materials, the most popular worldwide are reactive coatings (intumescent compositions that undergo thermal expansion) and heat-insulating materials (fireretardant plasters, mineral and fiber boards) [2,3].…”

Comparison of fire resistance of polymers in intumescent coatings for steel structures

“…The technology of intumescent coatings for steel structures has almost remained unchanged in the last 40 years. The main reactive components of the traditional IC are [1,2]: the acid donor is phosphates, ammonium polyphosphates (APP); the carbonizing agent is pentaerythrite (PE) or its analogs; the gas generating agent is the derivatives of melamine (MA), dicyandiamide, urea. In the form of a fire-retardant paint, IC additionally contains a polymer binder, pigment, fillers, and rheo logical impurities.…”

“…Thin-layer intumescent coatings are actively applied in fire safety practices as the best choice for the reactive fire protection of construction steel [1,2]. Such popularity is the result of the ability of intumescent coatings to provide effective fire protection solutions while preserving aesthetic characteristics and architectural design of steel construction [3,4].…”

Combined Heat Transfer Mechanisms in the Porous Char Layer Formed from the Intumescent Coatings under Fire

“…The inherent weakness of steel structures that cannot maintain their strength and stiffness at high temperatures is often addressed by applying insulation to their exposed surfaces, which delays the transfer of heat to the internal structure and, thus, increases the time required for the critical temperature of the steel structure to be reached [1]. Among the commonly used passive fire prevention measures, intumescent coatings have a strong application competitiveness, because they can provide efficient fire protection with a relatively thin thickness, and at the same time are practical and aesthetically pleasing [2]. Intumescent coatings generally form a porous char layer during their degradation and expansion under high temperature.…”