Mechanical Response and Analysis of Cracking Process in Hybrid TRM Composites with Flax Textile and Curauá Fibres.

Giuseppe Ferrara,Marco Pepe,Romildo Dias Toledo Filho,Enzo Martinelli

doi:10.3390/polym13050715

Giuseppe Ferrara, Marco Pepe + Show 2 more

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https://doi.org/10.3390/polym13050715

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Abstract

In recent years, the use of plant fibres in Textile-Reinforced Mortar (TRM) composites emerged as a valuable solution to increase their sustainability. Several studies carried out to mechanically characterize the so-called Natural TRMs, although showing promising results, also emphasised some drawbacks due to a severe deformability of the system and to durability issues. This study aims at improving the mechanical behaviour of Natural TRMs including impregnated flax textile (Flax TRMs) by the addition of short curauá fibres within the matrix. Flax TRM specimens were tested in tension to assess the influence of the fibre-reinforced mortar on the composite response. The crack pattern developed during the test was investigated via Digital Image Correlation analysis and by means of an analytical simplified model proposed by the authors. The addition of curauá fibres resulted in a denser crack pattern and in a significant decrease of the mean crack width (around 20%). The overall tensile response of Flax TRMs including curauá fibres resulted closer to the ideal three-linear behaviour of strain-hardening TRM composites with respect to the conventional Flax TRMs by also presenting an increase of dissipated energy of around 45%. This study paves the way for further analysis aimed at enhancing the mechanical performance of Natural TRMs adopting sustainable improvement techniques.

Highlights

Composites with inorganic matrices, generally referred to as Textile-Reinforced Mortar (TRM) systems, are getting more and more common for strengthening masonry structures, with a remarkable increase in the last decade due to their efficiency in enhancing bearing capacity against both in-plane an out-of-plane actions [1,2]
This paper showed the results of an experimental analysis aiming at assessing the influence of the use of short curauá fibres in the matrix of Flax TRMs on their tensile mechanical behaviour
The addition of short curauá fibre in the amount of 1% in weight increased the flexural strength of the mortar, but significantly reduced its workability at the fresh state: the addition of superplasticizer admixtures is needed to guarantee a proper implementation of the composite

Summary

Introduction

Composites with inorganic matrices, generally referred to as Textile-Reinforced Mortar (TRM) systems, are getting more and more common for strengthening masonry structures, with a remarkable increase in the last decade due to their efficiency in enhancing bearing capacity against both in-plane an out-of-plane actions [1,2]. The increasing awareness towards environmental issues pushes toward sustainable solutions for producing building materials and the use of recycled and renewable resources with lower environmental impact is increasingly required [7,8]. In this context, the use of plant fibres as reinforcement in cement-based composites has considerably increased, giving rise to a new class of sustainable building materials defined as biocomposites [9,10], characterised by an embodied energy equal to about one-fifth of the one required to produce conventional composite systems [11]. Several studies were carried out to explore the possible use of plant fibre-based textiles as internal reinforcement in composites, introducing the so-called Natural Textile-Reinforced Mortar (NTRM) systems

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