Design of strain hardening cement-based composites with alkali treated natural curauá fiber

The work in hand presents the design process of Strain Hardening Cement-based Composite reinforced with natural curauá fiber. The matrix fracture energy and matrix-fiber bond were studied and implemented into the theoretical model for critical fiber volume prediction, which was verified by mechanical tests for tensile, bending and compression strength. The influence of matrix-fiber bond on critical fiber volume is presented. The fiber properties are improved by two-stage treatment. Firstly, hot water (80 °C) washing in water changed every 3 h. Secondly, immersion in 1% solution of calcium hydroxide Ca(OH)2 with water for 60 min for calcium deposition on fiber surface to increase bond properties. The critical fiber volume predicted by the model was 4% for 20 mm treated curauá fiber and was verified on the composites, which presented strain-hardening behavior under tensile test and deflection-hardening under bending.