Rice Husk Shredding as a Means of Increasing the Long-Term Mechanical Properties of Earthen Mixtures for 3D Printing

This paper is part of a study of earthen mixtures for 3D printing of buildings. To meet the ever-growing environmental needs, the focus of the paper is on a particular type of biocomposite for the stabilization of earthen mixtures—the rice husk-lime biocomposite—and on how to enhance its effect on the long-term mechanical properties of the hardened product. Having assumed that the shredding of the vegetable fiber is precisely one of the possible ways to improve the mechanical properties, we compared the results of uniaxial compression tests performed on cubic specimens made with both shredded and unaltered vegetable fiber, for three curing periods. The results showed that the hardened earthen mixture is not a brittle material in the strict sense, because it exhibits some peculiar behaviors, anomalous for a brittle material. However, being a “designable” material, its properties can be varied with a certain flexibility to get as close as possible to the desired ones. One of the peculiar properties of the hardened earthen mixture deserves further investigation, rather than corrections. This is the vulcanization that occurs (in a completely natural way) in the long term, thanks to the mineralization of the vegetable fiber by carbonation of the lime.

Rice Husk Shredding as a Means of Increasing the Long-Term Mechanical Properties of Earthen Mixtures for 3D Printing

This paper is part of a study of earthen mixtures for 3D printing of buildings. To meet the ever-growing environmental needs, the focus of the paper is on a particular type of bio-composite for the stabilization of earthen mixtures – the rice husk-lime bio-composite – and on how to enhance its effect on the long-term mechanical properties of the hardened product. Having assumed that the shredding of the vegetable fiber is precisely one of the possible ways to improve the mechanical properties, we compared the results of uniaxial compression tests performed on cubic specimens made with both shredded and raw vegetable fiber, for three curing periods. The results showed that the hardened earthen mixture is not a brittle material in the strict sense, because it exhibits some peculiar behaviors, anomalous for a brittle material. However, being a “designable” material, its properties can be varied with a certain flexibility to get as close as possible to the desired ones. One of the peculiar properties of the hardened earthen mixture deserves further investigation, rather than corrections. This is the vulcanization that occurs (in a completely natural way) in the long term, thanks to the mineralization of the vegetable fiber by carbonation of the lime.

Bio-Based Rigid Polyurethane Foam Composites Reinforced with Bleached Curauá Fiber

This study aims to evaluate the influence of using a bleached Curauá fiber (CF) as filler in a novel rigid polyurethane foam (RPUF) composite. The influence of 0.1, 0.5 and 1 wt.% of the reinforcements on the processing characteristics, cellular structure, mechanical, dynamic-mechanical, thermal, and flame behaviors were assessed and discussed for RPUF freely expanded. The results showed that the use of 0.5 wt.% of CF resulted in RPUF with smoother cell structure with low differences on the processing times and viscosity for the filled pre-polyol. These morphological features were responsible for the gains in mechanical properties, in both parallel and perpendicular rise directions, and better viscoelastic characteristics. Despite the gains, higher thermal conductivity and lower flammability were reported for the developed RPUF composites, related to the high content of cellulose and hemicellulose on the bleached CF chemical composition. This work shows the possibility of using a Brazilian vegetable fiber, with low exploration for the manufacturing of composite materials with improved properties. The developed RPUF presents high applicability as enhanced cores for the manufacturing of structural sandwich panels, mainly used in civil, aircraft, and marine industries.

Effect of the Varying Percentage Diss Fiber on Mechanical Behaviour of the Based Polyester Bio-Composite

Improving the mechanical and physical properties of bio-composite materials involves the incorporation of plant fibers such as Jute, Hemp, Kenaf, Ramie, Sisal, Linen, etc. The existence of Diss grass (Ampelodesmos mauritanicus) in abundance in the east of Algeria especially in Khenchela region and taking into account their mechanical resistance and their low density, which justifies their choice of use in composite materials. Tensile and hardness tests for different volume fractions (from 05% to 20%) of short fibers of Diss are performed. The increase in fiber content and their treatment improves the mechanical characteristics of the composite materials. These concentration levels are added to a Polyester resin matrix. Our work relates to the study of a composite material reinforced by a vegetable fiber of which different volume ratio of short Diss fiber are considered. The results collected are purely experimental.

Design synthesis and performance of anti-collapse drilling polymer mud with higher stability

Purpose The purpose of this paper is to study the influence of different factors on mud performance, find the best conditions and synthesize a new type of anti-collapse drilling polymer mud with higher stability. The anti-collapse mechanism of drilling polymer mud was also suggested. Design/methodology/approach Exploring the influence of different molecular weight thickeners, filtrate reducers, soda ash addition and film-forming components on the mud performance, so as to obtain the best ratio of anti-collapse drilling polymer mud. Findings The results show that the use of vegetable glue, sulfonate copolymer and vegetable fiber powder can synthesize a high-viscosity, high-stability, collapse-resistant mud. When the mass ratio of vegetable fiber powder: vegetable glue: sulfonate copolymer is 40:1:2, the mud viscosity is 21.2 s, the fluid loss in 30 min is only 12.5 mL, and the mud film thickness is 1.5 mm, which is one ideal anti-collapse polymer mud. Originality/value Compared with ordinary polymer mud and bentonite mud, this anti-collapse polymer mud not only uses vegetable glue instead of traditional tackifiers but also effectively uses vegetable fiber powder produced from waste wood, which is environmentally friendly and highly stable specialty. It can effectively improve the safety and quality of construction during drilling in water-sensitive geology.

Effect of the Varying Percentage Diss Fiber on Mechanical Behaviour of the Based Polyester Bio-Composite

Improving the mechanical and physical properties of bio-composite materials involves the incorporation of plant fibers such as Jute, Hemp, Kenaf, Ramie, Sisal, Linen, etc. The existence of Diss grass (Ampelodesmos mauritanicus) in abundance in the east of Algeria especially in Khenchela region and taking into account their mechanical resistance and their low density, which justifies their choice of use in composite materials. Tensile and hardness tests for different volume fractions (from 05% to 20%) of short fibers of Diss are performed. The increase in fiber content and their treatment improves the mechanical characteristics of the composite materials. These concentration levels are added to a Polyester resin matrix. Our work relates to the study of a composite material reinforced by a vegetable fiber of which different volume ratio of short Diss fiber are considered. The results collected are purely experimental.