| Abstract: | Fracture behavior of polyester composite systems, polyester mortar and glass fiber reinforced polyester mortar, was investigated in mode I fracture using single edge notched beams with varying notch depth. The beams were loaded in four-point bending. Influence of polymer content on the flexural and fracture behavior of polyester composites at room temperature was studied using a uniform Ottawa 20–30 sand. The polymer content was varied between 10 and 18% of the total weight of the composite. The flexural strength of the polyester mortar systems increase with increase in polymer content while the flexural modulus goes through a maximum. The critical stress intensity factor (KIC) for the optimum polyester mortar (14%) was determined by two methods including a method based on crack mouth opening displacement. The KIC for polyester mortar is linearly related to the flexural strength. Polyester mortar (18%) reinforced with 4% glass fibers was also investigated, and crack growth resistance curve (KR) was developed with crack extension (Δa). A model has been proposed to represent the fracture toughness with change in crack length, KR - Δa relationship, of fiber reinforced polyester composite. |
