Improvement of flexural performance of fibre cements composite board through fibre impregnation

Abstract

Fibre-cement composite board (FCCB) is one of the most important construction products that can be employed in construction systems as an internal/external wall and also as a material for roofing or cladding. Largely, the main fibre used in FCCB is natural fibres; particularly cellulose fibres extracted from Kraft pulp. Exposing cellulose fibre in alkaline media as a result of cement hydration causes a deterioration on fibres. This laboratory research investigated pre-treatment methods for preventing or reducing cellulose fibres deterioration in alkaline media. Three types of solutions were examined; Potassium Sulphate, Magnesium Sulphate and Sodium Silicate, these were applied in the treatment of Kraft fibres. Next, three groups of specimens were made using laboratory simulated Hatcheck process, having six specimens in each group. Then, flexural performance; one of the most important mechanical properties of FCCB; was investigated in the aforementioned groups of FCCB aged 7 and 28 days. The results showed that Magnesium Sulphate has the best effect on improving the bond within fibre-cement interfacial zone and could increase the flexural strength of FCCB’s.