Degradación atmosférica de un recubrimiento de pintura intumescente

Abstract

The influence exerted by temperature on the resistant capacity of structural steel is well known. A highly efficient and increasingly widely used protection system for steel consists of the application of intumescent paints, which in the case of fire retard its destructive action. Their effectiveness is based on the property that when they come into contact with flames they react by swelling to form an insulating layer, referred to as intumescence, which impedes the propagation of heat. Though in general these paints do not require continuous maintenance, their service behaviour depends on the exposure conditions to which they are exposed. This paper studies the behaviour of an acrylated rubber type intumescent system exposed to two outdoor atmospheres. The same system is also studied with the protection of a topcoat paint layer. The coating's capacity to intumesce has been measured before and after its exposure to the corresponding atmospheres by means of fire resistance tests applied at laboratory scale. The evolution of the coating's behaviour with exposure time has been studied by means of thermal analysis (TG/DTA) and infrared spectroscopy (FTIR).