Sustainable and Nonconventional Construction Materials using Inorganic Bonded Fiber Composites

Holmer Savastano Junior, Juliano Fiorelli, Sergio Francisco Dos Santos

• Publisher: Woodhead Publishing
• Year: 2017
• Print ISBN: 9780081020012
• eBook ISBN: 9780081020029
• Topic: Technology & Engineering
• Subtopic: Materials Science
• Index: Technology & Engineering

Sustainable and Nonconventional Construction Materials Using Inorganic Bonded Fiber Composites presents a concise overview of non-conventional construction materials with a strong focus on alternative inorganic bonded fiber composites and their applications as construction components. It outlines the processing and characterization of non-conventional cementitious composites, which will be of great benefit to both academic and industrial professionals interested in research, development, and innovation on inorganic bonded fiber composites.The book gives a comprehensive review of the innovative research associated with building components based on inorganic bonded composites. Exploring both natural fibers as reinforcing elements and alternative inorganic binders based on agricultural and industrial wastes, this book also considers the performance and applications of fibrous composites as construction materials and components.- Dedicated to analyzing recent developments in inorganic fiber composites research- Discusses the broader subjects of processing, characterization, performance, and applications of non-conventional construction materials

Part 1

Engineered vegetable and other natural fibers as reinforcing elements

Outline

1 Lignocellulosic residues in cement-bonded panels

2 The effect of sodium hydroxide surface treatment on the tensile strength and elastic modulus of cellulose nanofiber

3 Interfacial transition zone between lignocellulosic fiber and matrix in cement-based composites

4 Treatments for viable utilization of vegetable fibers in inorganic-based composites

1

Lignocellulosic residues in cement-bonded panels

Rafael F. Mendes, Alan P. Vilela, Camila L. Farrapo, Juliana F. Mendes, Gustavo H. Denzin Tonoli and Lourival M. Mendes, Federal University of Lavras, Lavras, Brazil

Abstract

With the increasing production of cement-bonded panels due to growth in the construction sector, the use of alternative species as new lignocellulosic feedstocks have being studied to meet the demand of this rapid growth, as well as the use of forest and agricultural residues. This study aimed to evaluate the impact of different types of lignocellulosic feedstocks on the properties of cement-bonded panels. Residues of lamination of Pinus oocarpa and Eucalyptus urophylla wood, sugar cane bagasse, bamboo, and Pinus shavings were tested. Panels were formulated with lignocellulosic particles, Portland cement, water, and calcium chloride (CaCl₂) as additive. The variables for the processing of the panels are: nominal apparent density of 1.30 g/cm³; lignocellulosic:cement ratio of 1:2.5; water:cement ratio of 1:1.5; and hydration rate of water:cement of 0.25 and 4% of CaCl₂. Panels produced with the Eucalyptus wood from residues of lamination presented improved performance for all physical and mechanical properties. Chemical composition of the lignocellulosic feedstock seems to influence greatly the density of the panels. The sugar cane bagasse showed higher potential for using as cement reinforcement than bamboo particles.

Keywords

Nonconventional construction materials; lignocellulosic fibers; chemical composition; physical and mechanical properties; vegetable fibers

1.1 Introduction

Cement-bonded particleboards/panels are products manufactured from a mixture of Portland cement, chemical additives and particles generated from lignocellulosics.¹ Generally, these products combine the good qualities of cement (relatively high resistance to water, fire, fungus, and termite infestation coupled with good sound insulation) with those of wood (high strength to weight ratio, nailability, and workability).^2,3 Cement-bonded panels are used in building construction for their performance on fire resistance and thermal and acoustic insulation. Furthermore, the use of these panels allows saving of time, especially when applied in a modular way on the construction sites, resulting in the faster implementation of the construction.^4,5

According to Latorraca and Iwakiri⁶ and Fan et al.,³ the conifer species, especially the genus Pinus, are the most used woods for the production of cement-based panels, since they present relatively good compatibility with cement, without affecting the cure of the panels. Nevertheless, most lignocellulosic species can be used as reinforcement in cement-bonded panels.⁷ The major requirement refers to the chemical composition of the lignocellulosic material, which may impair the hydration of the cement matrix.⁸ With the increasing production of cement-bonded panels due to growth in the construction sector, several species have being studied as alternatives of rapid growth, as well as the use of forest and agricultural residues.^7,9,10

Large quantities of wood and agricultural residues are generated worldwide every year.^11,12 Those residues include wood sawdust and bark from sawmill operations and lamination residues, sugar cane bagasse, rice husks, wheat straw, straw, corn cob and stalk, coconut pith, ground nut husk, among others.^9,13–18 The use of the residues generated by the Brazilian agricultural and forestry industry into cement-bonded panels is an interesting solution for the wood demand problems of this sector; proper utilization of residues allows value addition to the lignocellulosic materials; improvement of the ductility, flexural, and tensile strengths, fracture toughness and crack-inhibiting properties of the cement matrix; lightweight character; and improvement of the thermal insulation properties.^19,20 The quality of the cement-bonded panels depends on several factors: the type of lignocellulosic material, density, particle size and volume, aspect ratio, mix design, mixing methods and processing and curing methods. In this context, this study aimed to evaluate the impact of different types of lignocellulosic feedstocks (Pinus and Eucalyptus residues, sugar cane bagasse and bamboo) on the performance of cement-bonded panels.

1.2 Material and methods

1.2.1 Raw materials

Residues of lamination of Pinus oocarpa and Eucalyptus urophylla wood, sugar cane bagasse (Saccharum officinarum L.), bamboo (Bambusa vulgaris) and Pinus (P. oocarpa) shavings were used as raw materials. Trees of P. oocarpa (around 28-years-old), E. urophylla (around 20-years-old) and B. vulgaris (around 3-years-old) culms were obtained from experimental plantings in the Federal University of Lavras (UFLA), in Lavras/MG, Brazil. Sugar cane bagasse was collected in the Usina Monte Alegre, in Areado/MG, Brazil.

Eucalyptus and Pinus logs were stored in a water tank at 65°C for 24 h. This process is required to promote the softening of the lignin, facilitating the lamination process. The lamination process was carried out to obtain veneers with 1.5-mm thickness. The residues generated during the veneers lamination were used to generate particles for production of cement-bonded panels.

Bamboo culms, sugar cane bagasse and the residues of Pinus and Eucalyptus were processed in a hammer mill to generate “sliver” particles. After this step the particulate material was sieved, and the particles that passed through the 2-mm sieve and were retained in the 0.5-mm sieves, were selected. The resulting particles present dimensions of around 4 mm×1.5 mm×1.0 mm.

The pinus logs were processed for removal of boards. The boards had their dimensions adjusted, which generated waste shavings with dimensions of around 25 mm×25 mm×2 mm.

Ordinary Portland cement (CPV-ARI, NBR5733²¹), water and calcium chloride (CaCl₂)...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• List of contributors
• Foreword
• Summary
• Introductory remarks—the nonconventional materials (NOCMAT) for sustainable infrastructure regeneration in 21st century
• Part 1: Engineered vegetable and other natural fibers as reinforcing elements
• Part 2: Alternative inorganic binders based on agricultural and industrial wastes
• Part 3: Nonconventional cementitious composites processing and characterization
• Part 4: Application and performance of fibrous composites as construction materials and components
• Index