Composite repairs of pressure vessels and transmission pipelines are installed in a wide variety of ambient conditions. The installation of epoxies utilized can range from arid environments with almost no humidity to tropical conditions of nearly 100% humidity or even completely submerged in water. This paper presents the methodology and results from an initial effort to determine the effects of humidity on the strength of certain epoxy matrix composite repairs.
The effect on final strength of a composite repair specimen cured under a variety of ambient humidity is presented from experimentation with specimens cured below 20% humidity and at approximately 96% humidity in a climate controlled chamber. The effects on final strength, stiffness, and hardness, are observed and recorded to note the difference between the varying conditions. The compilation of data is analyzed to determine what considerations need to be made for various levels of humidity at the time of installation for composite repairs installed on pressure vessels and piping.
Results are presented to show that prediction of curing time and final strength are achievable with reasonable accuracy given sufficiently accurate humidity measurement during the curing process.