Fracture analysis of vinyl ester composites under microwave condition

Abstract

Vinyl ester (VE) with 33% Flyash composite has been widely used in the construction industry due to its superiority material properties but these composites suffer considerable shrinkage during the curing and hardening processes. Some researchers have proven that vinyl ester composite cured under microwave heat treatment will reduce the shrinkage problem. This purpose of this project is to research, measure and compare the fracture toughness of vinyl ester composite cured under ambient and microwave conditions by using the short bar test. Furthermore, the fracture surface is investigated by using the Scanning Electron Microscope (SEM). The specimens were fractured by using the MTS 810 Material Testing Systems and the value of fracture toughness was obtained through some calculations. The result was further proven from the SEM microscopy analysis where the lower value of fracture toughness specimen will have more microvoid or bubbles comparing to the specimen with the higher value of fracture toughness. The result analysis tool called Latin Squares was used to determine which treatments were most effective in maintaining the fracture toughness while reducing the shrinkage of vinyl ester composite, and by how much, and which are worthless, so we can weight the economic alternatives.