Flexural Fatigue Failure Characteristics of an Engineered Cementitious Composite and Polymer Cement Mortars

Abstract

The fatigue failure characteristics of Engineered Cementitious Composite (ECC) were investigated by four-point flexural fatigue tests in comparison with two types of Polymer Cement Mortar (PCM). The fatigue failure mechanisms were observed, and the damage evolutions were measured for all shotcreted specimens. The results showed that ECC performs the improved fatigue life and that it exhibits a bilinear fatigue stress-life relation on a semi-logarithmic scale. ECC under fatigue loading shows much more ductility than PCMs, because the failure of ECC involves the initiation of multiple cracks, the propagation of those cracks, and the localization to a single crack, while the failure of PCMs involves only the initiation of a single crack.

Examination at a Material and Structural Level of the Fatigue Life of Beams Strengthened with Mineral or Epoxy Bonded FRPs: The State of the Art

“…Both polyvinyl alcohol fibers (PVA) and the high modulus polyethylene fibers (PE) are used in ECC (Li 2008). In general, ECC exhibits high ductility under fatigue loading and its general behavior shows three phases similar to the previous material (Suthiwarapirak et al 2002;Xu and Liu 2011). However, its behavior under fatigue loading is different from the previously mentioned materials.…”

“…When any of these types are used, it is most important that both the hydrated cement and polymer thoroughly mix to produce a monolithic matrix. Under fatigue loading, the way in which PMM fails can be split into three phases (Suthiwarapirak et al 2002). First, after the initial few applications of the cyclic load, numerous microcracks on the tension surface start that lead to significantly increased damage.…”

“…The second stage resists the effects of fatigue loading longer than the first stage. Suthiwarapirak et al (2002) found from their study that the PMM exhibited very brittle behavior under fatigue loading.…”

“…The fatigue life models for two types of polymer modified mortar were described by Suthiwarapirak et al (2002). They used a low ratio of fibers (less than 0.5%) which did not improve the tensile properties of the mortar.…”

Avaliação da resistência a fadiga dos Engineered Cementitious Composites (ecc), reforçados com fibra de polipropileno e produzidos com adição de cinza de casca de arroz

“…Na Figura 11 constam dados de ensaios de fadiga em ECC realizados por diferentes pesquisadores [8][9][13][14][15], incluindo os produzidos nesta pesquisa. Os ensaios de fadiga são influenciados por muitos fatores, dos quais se pode destacar a frequência aplicada nos ciclos de carga, os tipos de materiais presentes nos compósitos, os modos de carregamento, a variação entre σ máx e σ mín , entre outros.…”