2011 Volume 65 Issue 1 Pages 470-476
The mechanical properties of fiber－reinforced porous concrete may be improved by strengthening of binder. In general, the polymer modification of cement mortar improves the strength and adhesion properties of the mortar. The purpose of this study is to investigate the effect of the polymer modification of the cement mortar as a binder on the compressive and flexural behavior of the fiber－reinforced porous concrete. Polymer－modified mortars with various polymer－cement ratios are prepared as the binder for fiber－reinforced porous concretes using polymer for cement modifier. The fiber－reinforced porous concretes using polymer for cement modifier are prepared with various vinylon fiber contents, water－cement ratios and polymer－cement ratios, and subjected to compressive behavior, flexural behavior and voids tests. As a result, regardless of the polymer－cement ratio, the compressive and flexural strengths, modulus of elasticity and flexural toughness of the fiber－reinforced porous concretes using polymer for cement modifier increase with increasing fiber content up to 0.5%. The compressive strength and modulus of elasticity of the fiber－reinforced porous concretes using polymer for cement modifier are increased with an increase in polymer－cement ratio up to 4.0% regardless of the fiber content. The flexural strength and flexural toughness of the fiber－reinforced porous concretes using polymer for cement modifier are also increase with increasing polymer－cement ratio up to 6.0%. Brittleness of the fiber－reinforced porous concretes using polymer for cement modifier is improved by increasing the polymer－cement ratio. From the test results, the polymer modification of cement mortar as a binder for the fiber－reinforced porous concrete is effective technique for improving the mechanical properties of the fiber－reinforced porous concrete. The marked improvement of flexural behavior of the fiber－reinforced porous concretes using polymer for cement modifier is recognized with an increasing the polymer－cement ratio.
