Influence of an Impregnation Treatment on the Morphology and Mechanical Behaviour of Flax Yarns Embedded in Hydraulic Lime Mortar

Abstract

The increasing attention toward environmental aspects has led, also in the sector of construction materials, to the need for developing more eco-friendly solutions. Among several options, the employment of low energy raw materials appears as an efficient solution intended to enhance the sustainability of building structures. One of the applications moving in this direction is the use of plant fibers as a reinforcement in cement-based composites, hence named as natural textile reinforced mortar (NTRM) composites. Although representing a promising technique, there are still several open issues concerning the variability of plant fibers properties, the durability, and the mechanical compatibility with the mortar. This study aims at investigating the influence of an impregnation process on the thread’s morphology and on the mechanical response. Therefore, the geometry of dry and impregnated flax threads is identified by using scanning electron microscope (SEM) images analysis, and their mechanical response in tension is assessed. In addition, the fibers-to-mortar bond behavior is investigated by means of pull-out tests. The proposed results show that the impregnation procedure employed, although not improving the fibers-to matrix bond, leads to a standardisation of the threads morphology and reduces the thread’s deformability in tension, and paves the way for further investigations on a larger scale.

Development of Interlocking Concrete Blocks with Added Sugarcane Residues

“…Although the purpose of this study was not to achieve the standards of "water-retentive type" interlocking blocks, it is possible to see from Figure 7 that the water retention content increased with the addition of the sugarcane residues. In the case of BFL5, the water retention content achieved a value of 0.118 g/cm 3 , while the water retention content of the control composite C was just 0.087 g/cm 3 . This increase may be due to the bagasse fibers having a good water-holding capacity and also to the probably large number of voids between the fiber and the matrix.…”

“…Figure 7 shows the water retention content of interlocking concrete blocks. According to the "Manual for Interlocking Blocks Pavement Design and Construction" published by Japan Interlocking Blocks Pavement Engineering Association (JIPEA), the water retentivity of the "water-retentive type" interlocking blocks has to be greater or equal to 0.15 g/cm 3 . Interlocking Blocks Pavement Engineering Association (JIPEA), the water retentivity of the "waterretentive type" interlocking blocks has to be greater or equal to 0.15 g/cm 3 .…”

“…Bio-renewable materials have been used as a matrix or reinforcement in many applications and they offer important advantages such as ease of fabrication, higher mechanical properties, high thermal stability, and many more [2]. However, although promising, there are still several open issues concerning the variability of plant fiber properties, durability, and mechanical compatibility with the matrix [3]. Among several types of bio-renewable materials, there is bagasse, which is a residue of sugarcane [4].…”

Meso-Scale Formulation of a Cracked-Hinge Model for Hybrid Fiber-Reinforced Cement Composites

“…Fiber-reinforced cementitious composites (FRCCs) are a class of concrete-like material developed in the last two decades with the aim of mitigating the inherent fragility of concrete in tension [1]. Several types of fiber are currently adopted as spread reinforcement in FRCCs, which range from the very common steel fibers [2][3][4][5], to the ones either made of plastics [6] or, more recently, obtained from plants [7,8], or produced by recycling waste tires [9][10][11]. Moreover, FRCCs can also be produced by blending different types of fibers to produce a class of composites often referred to as hybrid-FRCCs (Hy-FRCCs) with the aim to mobilize a synergistic action from each fiber [12][13][14][15][16][17].…”

Experimental Study on the Adhesion of Basalt Textile Reinforced Mortars (TRM) to Clay Brick Masonry: The Influence of Textile Density

“…Depending on the materials' properties, such as nature of the substrate, matrix strength, textile stiffness, the failure mode may interest the substrate-matrix interface, textile-matrix interface, or fiber failure [22][23][24][25]. Moreover, investigations were carried out by adopting plant fibers, such as hemp, flax, sisal, and coir, as reinforcement of TRM systems, showing the latter as a potential solution to increase the sustainability of the systems but still characterized by mechanical issues mainly related to the low stiffness of the textile, adherence properties, and durability aspects [26][27][28][29][30].…”