Preparation and Performance of Cement Mortar Reinforced by Modified Bamboo Fibers

Natural Fibre Composites and Their Mechanical Behaviour

At present, natural-fibre-reinforced-composites (NFRCs) are seen as realistic alternatives to synthetic- (e [...].

Conservation Environments' Effect on the Compressive Strength Behaviour of Wood-Concrete Composites

This paper addresses the issues in making wood-concrete composites more resilient to environmental conditions and to improve their compressive strength. Tests were carried out on cubic specimens of 10 × 10 × 10 cm³ composed of ordinary concrete with a 2% redwood- and hardwood-chip dosage. Superficial treatments of cement and lime were applied to the wood chips. All specimens were kept for 28 days in the open air and for 12 months in: the open air, drinking water, seawater, and an oven. Consequently, the compressive strength of ordinary concrete is approximately 37.1 MPa. After 365 days of exposure to the open air, drinking water, seawater, and the oven, a resistance loss of 35.84, 36.06, 42.85, and 52.30% were observed, respectively. In all environments investigated, the untreated wood composite concrete's resistance decreased significantly, while the cement/lime treatment of the wood enhanced them. However, only 15.5 MPa and 14.6 MPa were attained after the first 28 days in the cases of the redwood and the hardwood treated with lime. These findings indicate that the resistance of wood-concrete composites depends on the type of wood used. Treating wood chips with cement is a potential method for making these materials resistant in conservation situations determined by the cement's chemical composition. The current study has implications for researchers and practitioners for further understanding the impact of these eco-friendly concretes in the construction industry.

Innovative Industrial Use of Bamboo as Key “Green” Material

This study investigates the use of bamboo in different industrial sectors, including construction and energy, to highlight its mechanical properties, resources, and innovative use through information gathered from Ethiopia, Guinea, and Georgia (Caucasus) as study cases. Research shows that bamboo is a common plant and an easily accessible material possessing remarkable characteristics for different applications in different countries. The main goal of this study is to highlight the properties of bamboo that make it an interesting material with applications in several economic branches as a green material positively influencing the environment. The results of this study show a utilitarian use of bamboo in industries where production is based on bamboo or bamboo-related materials and wide possibilities for using bamboo in innovative and creative ways. Bamboo’s mechanical and physicochemical properties are discussed as well as its potential as a raw material for use in composites or for the production and processing of semi-finished products and parts of end devices, all with a view to its positive environmental impact.

Potential of Using Amazon Natural Fibers to Reinforce Cementitious Composites: A Review

The engineering application of natural lignocellulosic fibers (NLFs) has been intensifying all over the world due to their low cost and abundance, as well as their being eco-friendly and presenting favorable technological properties in polymeric and cementitious composites. Brazil, especially the Amazon region, owing to its climate and geographic position, has an abundant variety of NLFs that are still unexplored with great potential for use in various composite materials and applications such as civil construction, automobile parts and armor. Therefore, this review aims to establish a parallel between the technological properties of cementitious composites reinforced with Amazon NLFs, both in fresh and hardened states, and to analyze, compare results and contribute to a better understanding of the similarities and differences between the types of reinforcements. A relevant contribution of this review is the possibility of improving knowledge about Amazon NLFs, showing their potential for application in eco-friendly materials, in addition to contributing to studies with new NLFs not yet applied in composite. For this, it was necessary to carry out a literature survey on the physical, chemical and mechanical properties of cementitious composites reinforced with NLFs, in addition to analyzing case studies involving fibers such as curaua, açai, bamboo, jute and sisal. It can be concluded that the physical and chemical characteristics of the Amazon NLFs directly influence the technological properties of cementitious compounds, such as mechanical strength and water absorption. However, there might be a need for surface treatment aimed at improving adhesion and durability of the cementitious composite. Finally, some suggestions for future research work are highlighted in order to show the need to continue investigations on the application of Amazon NLFs in cementitious composites.

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

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.