Influence of aggressive environmental conditions on mechanical properties of grp composites

Abstract EN

Today, with the increasing needs for performance-oriented materials and structural systems, he development and introduction of advanced composite materials represents a milestone in materials technology.

Some of the intriguing characteristics of such materials are the high stiffness to weight ratio and the ability to be tailored to fit certain design or loading conditions.

The combination of diverse material components produces performance far exceeding that of the individual elements.

This synergism makes composite materials both enabling and pervasive in civil and industrial applications.

However, hydrothermal and aggressive environmental conditions may have a severe impact on polymer composites mechanical properties, and hence their durability.

This study investigates the influence of some aggressive environmental conditions on the basic mechanical properties of glass fiber reinforced polymer composites.

The test samples were fabricated in the laboratory by hand lay-up method and cured at room temperature and atmospheric pressure.

By using 20% glass fiber volume fraction in polyester matrix, three fiber orientations had been considered ; unidirectional, bidirectional, and chopped.

The samples were immersed for up to 90 days in chemicals having concentrations of 5, 10, and 20 %, tap water, sewage water, and hydraulic oil.

The influence of variations in these parameters on the mechanical behavior of GRP composites was investigated by measuring the corresponding changes in the tensile strength, fracture toughness, and modulus of elasticity.

The general trend of the results indicates that mechanical properties decrease with the increase of concentration and / or immersion period.

The study also show that subjecting GRP composites to aggressive environmental conditions for extended period of time, 90 days in this investigation, reduces the tensile strength and fracture toughness by 50 % and 27 % respectively.

Moreover, the major drop in tensile strength and fracture toughness occurs in the first 30 days of immersion in all used chemicals and solutions.