| Title |
Effect of Aggregate Size on the Behavior and Fracture Characteristics in Ductile Fiber-reinforced Cementitious Composites |
| Authors |
Lee Young-Oh ; Yun Hyun-Do |
| Keywords |
Ductile Fiber-reinforced Cementitious Composites ; Acoustic Emission ; Bridging Action ; Felicity Ratio |
| Abstract |
Fiber is an important ingredient in ductile fiber-reinforced cementitious composite (DFRCC), which can control fracture of cementitious composite by bridging action. Also in compliance with the action of the fiber and the aggregate size, it showed a different failure mechanism. For practical application, it is needed to investigate the fractural behavior of the DFRCC and to understand the micro-mechanism of cement matrix with reinforcing fiber. In order to clarify characteristics of fracture process in the DFRCC, acoustic emission (AE) technique is carried out the analysis and evaluation of DFRCC damage by acoustic emission technique under flexural, compressive loadings. The AE signals were monitored by AMSY4 AE instrumentation during the entire loading period. All the specimens are reinforced with 1.5%(by volume) PVA(Polyvinyl alcohol) fiber, silica, 0.6, 1.2 and 2.5mm aggregates. The fiber was used PVA. The damage progress with a stress stage was divided four levels under monotonic loading. The test results showed that the damage progress of the DFRCC was characteristic for the aggregate size. As a result of analyzing the felicity ratio (FR) values, it is shown that this values can be used for evaluating the degree of DFRCC damage. On the whole the felicity ratio values of DFRCC is shown between 0.7 and 0.9. And, the AE kaiser effect was existed in the all DFRCC. Also, the damage behavior and the microscopic fracture process of the DFRCC was evaluated using the AE parameters, such as hits, frequency, amplitude and felicity ratio. From the AE parameters, fracture process of the DFRCC was evaluated from the AE characteristic. |