Stiffness Behavior of Sisal Fiber Reinforced Foam Concrete under Flexural Loading

Abstract

This work investigated the static and fatigue behavior of sisal fiber-reinforced foam concrete under flexural loading. In particular, the effect of fiber content (0–0.3 vol.%) was determined by measuring the strains at two positions (mid-span and near the support of the beam) to relate with the flexural stiffness. The results showed that under static loading, sisal fiber can increase the flexural strength and decrease the flexural stiffness of the foam concrete when the specimen broke, especially, as the sisal fiber content was taken as 0.15%. Under cyclic loading, the flexural stiffness of the plain foam concrete decreased rapidly at the beginning, sisal fiber can delay the stiffness degradation of composites. When the sisal fiber content is below 0.05%, a linear relationship between the flexural stiffness and the logarithmic fatigue life of the composite was found. But for fiber content above 0.05%, another linear relationship was obtained when the fatigue life was used. It was also found that the flexural stiffness obtained from two positions was linearly correlated. If the slopes of the fitting lines were fixed as 2, a mathematical model between the flexural stiffness at the mid-span and the flexural stiffness near the support was obtained.

Keywords

• foam concrete
• sisal fiber
• flexural stiffness
• fatigue life