Hornification on vegetable fibers to improve fiber-cement composites: A critical review

Fibers are added to cement products to increase its flexural properties and reduce crack propagation. In this context, different types of fibers are incorporated on cement materials, and researches on the use of vegetable fibers are being developed along the years. Its use is grounded by its renewable sources and low energy consumption during the production. Even though vegetable fibers have good mechanical properties, the durability of the fiber-cement composite is reduced by the natural properties of the fiber, such as its hygroscopicity. A wide range of treatments can be applied to the fibers to solve this issue, and in this paper, a systemic review were made concerning the application of wetting and drying cycles to cause hornification and its effects on the fibers and its adherence to the cement matrix. Treatment aspects such as the number of cycles, duration of wetting and drying procedures, methods used to assess the effects of the treatment on chemical, mechanical and physical aspects of fibers and fiber-cement composites were summarized and the results obtained were discussed. The effects of hornification until ten cycles were successful in reducing vegetable fibers absorption capacity and improving its dimensional stability, hence improving the adherence between fiber and matrix in most of the cases. Opportunities for further development on the application of this treatment were also presented.

Automated summary

This paper provides a systematic review on the application of wetting and drying cycles for hornification of vegetable fibers in cement composites. The effects of this treatment on the chemical, mechanical, and physical properties of fibers and fiber-cement composites were discussed. The results showed that hornification through ten cycles successfully reduced fiber absorption capacity and improved dimensional stability.