Mixture optimization of epoxy base concrete for achieving highest fracture toughness and fracture energy values using Taguchi method

Manufacturing polymer concrete (PC) with suitable performance against cracking is an important issue for using these composite materials in practical applications. Fracture toughness and fracture energy of such randomly distributed aggregates inside the matrix of polymeric resin is affected by the mix design and percentages of PC ingredients. In this research, the optimum composition of epoxy base PC mixture made of four ingredients (epoxy resin, fine and coarse silica aggregate and E-glass fiber) was obtained using a L32 Taguchi design of experiment method. Some fracture toughness tests under mode I were conducted on symmetric semi-circular bend specimen according to design of experiment suggested by Taguchi method. The initial range for each PC ingredient was selected as: 0-2% fiber, 20-35% fine aggregate, 13-28% epoxy resin, and 41-56% coarse aggregate, and it was found that the mixture containing maximum resin (25-28%), moderate fine filler (28-31%), minimum per-centages of fiber and coarse aggregate can provide the highest fracture energy and fracture toughness values.