Bond Behaviour of Treated Natural Fibre in Concrete

Abstract

The use of leaflet ribs from oil palm trees - Oil Palm Broom Fibres (OPBF) in reinforcingcement composites have shown some prospects according to recent studies. However, only little isunderstood regarding their bond interaction with cement matrices. Samples were prepared toinvestigate the pull-out response of OPBF in both single and combined form from concrete. For thecombined fibres, single OPBF strands were wound around one another longitudinally (in helical form)to form tendons. A comparison was made between the maximum bond strengths of untreated andtreated OPBF in concrete. The OPBF were pre-treated by soaking in sodium hydroxide andtriethylvinylsilane solutions to improve their bond strength with concrete. The reported treatmentscould improve the potential of OPBF tendons as reinforcement in lightly loaded concrete beamsultimately resulting in an environmentally friendly and affordable construction.

Fiber Reinforced Concrete with Natural Plant Fibers—Investigations on the Application of Bamboo Fibers in Ultra-High Performance Concrete

“…Similar positive effects on bonding have also been observed in studies of cementitious materials. In studies by Momoh et al [51], alkaline pretreatment of oil palm broom fibers increased the mean transferable bond stress by 16% from 0.56 N/mm 2 to 0.65 N/mm 2 after 28 days. Yan et al [17] investigated the flexural behavior of beams made of normal-strength concrete (with a compressive strength of 22.4 N/mm 2 ) and reinforced with 1.0 wt% o.c.…”

“…When plant fibers are used in concretes, another problem arises in addition to the comparatively poor bond: the degradation in an alkaline environment. Although the cellulose fibers, which are decisive for the tensile strength, are relatively alkali-resistant compared to the other fiber components, prolonged exposure to an alkaline environment, as prevails in conventional concretes and mortars, leads to embrittlement and slow degradation of the cellulose fibers [18,21,55] as well as to a decrease in the transferable bond stress [51].…”

Zugtragverhalten von Betonbauteilen mit getränkter Textilbewehrung aus Flachsfasern

“…von lamellen‐ oder stabförmigen Naturfaserbewehrungen wurde in den letzten Jahren ebenfalls untersucht. Beispielsweise konnte mit Auszugsversuchen (Pull‐out‐Versuchen) für in Natriumhydroxid‐ und Triethylvinylsilan getränkte Ölpalmfasern [30] und für Bambusbewehrung [31] eine ausreichend hohe Verbundfestigkeit im Beton nachgewiesen werden.…”

“…getränkte Ölpalmfasern [30] und für Bambusbewehrung [31] eine ausreichend hohe Verbundfestigkeit im Beton nachgewiesen werden.…”