Alfa Natural Fiber Composite Reinforcement for Concrete Beams

Abstract

Lightweight, corrosion-resistant, and longer-lasting composite materials are increasingly used as primary load-bearing materials in structures' design. The cost of rehabilitating structures is lower than that of demolishing and rebuilding them again. Therefore, economical, and eco-friendly materials could extend the life of the structures and reduce the carbon di-oxide footprint on the environment. The purpose of this paper is to present a composite hollow body that can be inserted in reinforced concrete beams. The priority was to use more economical, biodegradable, and recyclable local natural fibers. The goal is to get lighter but stronger beams. The main innovation on this work is the usage of a composite made from natural fiber. A 3D finite element model of the 5 m span beam is developed to see in detail the beam's behavior and the composite reinforcement behavior. A classical reinforced concrete beam is compared to composite shells reinforced one. As a result, the beam is lightened, the deformation is relatively reduced, the traction in concrete is reduced, and the stress in steel bars is increased but remains far from the steel's elastic limit. An experimental work was done based on 40 mm x 40mm x160 mm beams to verify the correlation of the finite element model parameters with experimental results. The results show a good correlation. The weight of the beam 5 m span beam is reduced by 26.65% without affecting its behavior. For the reinforced and non-reinforced 5 m span beams, at a similar deflexion of nearly 0.7 mm, similar stress in concrete of about 2.3 MPa and similar stress in steel bars of about 10 to 13 MPa, the maximal stress in the composite is equal to 0.460 MPa which is insignificant compared to the composite failure stress, which is about 229 MPa. The composite has a long-life and can support the efforts if the beam must be rehabilitated, for example. Consequently, lightened beams can be used in reinforced concrete structures made of non-lightened elements and have the same structural behavior.

Natural fibres and biopolymers in FRP composites for strengthening concrete structures: A mixed review

“…Reinforced concrete (RC) beams and concrete columns were the most member type strengthened with biobased FRP, with research considering these member types accounting for 40% and 37%, respectively. Concrete beams [45][46][47][48][49][50][51][52][53][54][55][56] and RC columns [57,58] represented 14% and 2% of the members strengthened. RC slab [59], concrete slab [60], RC wall [61], masonry brick [62], masonry wall [63] and wood laminated beam [64] had a single occurrence.…”

The Viscoelastic Comportment of Composite Plates Reinforced with Synthetic and Natural Alfa (Stipa tenacissima L.) Fibers for Structural Applications

“…Composite materials, which are composed of a combination of different types of fibers, have a wide range of applications in various fields, such as crash and safety [1], [2], civil engineering [3]- [5], and biomechanics [6]- [8]. Researchers in Tunisia have been investigating using natural fibers [9]- [14], including palm [15] and cellulosic fibers [16]- [18], in composite materials to utilize local resources and promote sustainability.…”

Road guardrail beam made of natural stem (Stipa tenacissima L.) eco-composite: Impact energy absorption improvement by stems and pre-tensioning

“…CFRP plates are clamped and prestressed by clamping. 32 Composites are used as external structures in civil engineering as reinforcements 33 and as prestressing bars or cables. 34 Prestressed carbon fibers are presented in references 35.…”