ACI-SP-224-2004.pdf
THIN REINFORCED CEMENT-BASED PRODUCTS AND CONSTRUCTION SYSTEMS Editor Ashish Dubey American Concrete Institute“ Advancing concrete knowledge S P-224 Copyright American Concrete Institute Provided by IHS under license with ACI Licensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 03/16/2007 19:15:19 MDTNo reproduction or networking permitted without license from IHS -,-,- Copyright American Concrete Institute Provided by IHS under license with ACI Licensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 03/16/2007 19:15:19 MDTNo reproduction or networking permitted without license from IHS -,-,- Thin Reinforced Cement-Based Products and Construction Systems Editor Ashish Dubey American Concret e Ins t ¡tu te“ Advancing conmete knowlei SP-224 Copyright American Concrete Institute Provided by IHS under license with ACI Licensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 03/16/2007 19:15:19 MDTNo reproduction or networking permitted without license from IHS -,-,- First printing, November 2004 DISCUSSION of individual papers in this symposium may be submitted in accordance with general requirements of the AC1 Publication Policy to AC1 headquarters at the address given below. Closing date for submission of discussion is May 2005. All discussion approved by the Technical Activities Committee along with closing remarks by the authors will be published in the September/October 2005 issue of either AC1 Structural Journal or Materials Journal depending on the subject emphasis of the individual paper. The Institute is not responsible for the statements or opinions expressed in its publications. Institute publications are not able to, nor intended to, supplant individual training, responsibility, or judgment of the user, or the supplier, of the information presented. The papers in this volume have been reviewed under Institute publication procedures by individuals expert in the subject areas of the papers. Copyright O 2004 AMERICAN CONCRETE INSTITUTE P.O. Box 9094 Farmington Hills, Michigan 48333-9094 All rights reserved, including rights of reproduction and use in any form or by any means, including the making of copies by any photo process, or by any electronic or mechanical device, printed or written or oral, or recording for sound or visual reproduction or for use in any knowledge or retrieval system or device, unless permission in writing is obtained from the copyright proprietors. Cover Page Photonraph The Clubhouse at Abu Dhabi - The building demonstrates the use of thin cementitious panels as exterior cladding. Photograpli courtesy of Fibrex LLC, Abu Dhabi Printed in the United States of America Editorial production: Lindsay K. Kennedy Library of Congress catalog card number: 20041 14457 ISBN: 0-8703 1-1 59-X Copyright American Concrete Institute Provided by IHS under license with ACI Licensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 03/16/2007 19:15:19 MDTNo reproduction or networking permitted without license from IHS -,-,- PREFAíE The use of thin reinforced cementitious products continues to grow rapidly today in a variety of construction applications worldwide. Thin reinforced cementitious products are strong and tough, dimensionally stable, fire resistant, and possess excellent moisture resistance and environmental durability. With the continued rapid decline in the use of asbestos fibers as reinforcement in thin cementitious products, several advancements have occurred in the field as a result of the development of new types and forms of reinforcement for thin cementitious products. Also, several advancements have taken place in the material science and manufacturing methods of cementitious materials for thin reinforced cementitious products. This publication contains the papers originally presented in a symposium on the topic of thin reinforced cementitious products organized by AC1 Committee 549 on Thin Reinforced Cementitious Products and Ferrocement during the AC1 2003 Spring Convention held in Vancouver, Canada. The symposium explored current state-of-the-art and recent advances in material science, manufacturing methods, and practical applications of thin reinforced cementitious products. The topics covered in this publication include material science oftextile reinforced concrete, use of textile reinforced concrete for integrated formwork and exterior cladding panels, prestressed thin-sheet concrete products, ultra-high-performance thin precast concrete products, production of concrete tubes by centrifugation method, freezing-and-thawing durability of commercial fiber-reinforced cement boards, structural evaluation of cernent- skin sandwich building systems, microwave accelerated curing method for producing precast cementitious products, history of glass fiber-reinforced concrete (GFRC) products, and niodeling of cement-based laminate composites. The papers presented in this publication have beeu peer reviewed by experts in the field, according to the guidelines established by the American Concrete Institute. The future of thin reinforced cementitious products depends largely on their ability to compete cost effectively with similar products made using other materials such as metals and plastics. For future research and development, this entails understanding and optimizing fiber-reinforced cementitious compositions from a fundamental material science perspective; developing and implementing the use of cost-effective raw materials, particularly reinforcing fibers and other forms of reinforcement; and developing efficient manufacturing methods to produce thin reinforced cementitious products. Ashish Dubey Editor Chair, ACI Committee 549 Thin Rei forced Cenrentifious Pi-odircts and Ferrocement iii Copyright American Concrete Institute Provided by IHS under license with ACI Licensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 03/16/2007 19:15:19 MDTNo reproduction or networking permitted without license from IHS -,-,- iv Copyright American Concrete Institute Provided by IHS under license with ACI Licensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 03/16/2007 19:15:19 MDTNo reproduction or networking permitted without license from IHS -,-,- TABLE OF CONTENTS . Preface 111 SP-224-1: GFRC-30 Years of High Fiber Cement Composite Applications Worldwide . 1 by G. T. Gilbert SP-224-2: Towards Prestressed Thin-Sheet Glass Concrete Products 2 1 by G. Vilkner and C. Meyer SP-224-3: Textile Reinforced Concrete: Investigations at Different Levels . 33 by J. Hegger, A. Sherif, O. Bruckermann, and M. Konrad SP-224-4: Textile Reinforced Concrete (TRC) for Integrated Formworks 45 by W. Brameshuher, M. Koster, J. Hegger, S.Voss,T. Gries,M. Barlé, H.-W. Reinhardt, and M. Krüger SP-226.5: Exterior Cladding Panels as an Application of Textile Reinforced Concrete 55 by J. Hegger, H. Schneider, A. Sherif, M. Molter, and S. Voss SP-224-6: Ultra-High Performance Concrete with Ductility: Design, Prototyping, and Manufacturing of Panels and Boxes 7 1 by D. Zakariasen and V. Perry SP-224-7: New Cement Composites for Thin Structural Products 89 ,by E. Parant and P. Rossi SP-224-8: Structural Evaluation of Cement Skin Sandwich Building System . 10 1 by Y. Shao, E. Blain-Cosgrove, and B. Robinson SP-224-9: Properties of Short Fiber Reinforced Cement Paste for Concrete Tubes Produced by Centrifugation Method . 1 I3 by D. Hesselbarth and J. Kaufmann SP-224- 1 O: Temperature Controlled Microwave Acclerated Curing of Precast by K. C. G. Ong, C. P. Teo, C. H. Shum, L. H. J. Wong, S. T. Tan, and C. T. Tam Ferrocement Secondary Roofing Slabs 1 27 SP-224- 1 I : Freeze-Thaw Durability of Commercial Fiber-Reinforced Cement Board . 145 by K. G. Kuder and S. P. Shah V Copyright American Concrete Institute Provided by IHS under license with ACI Licensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 03/16/2007 19:15:19 MDTNo reproduction or networking permitted without license from IHS -,-,- SP-224-12: Crack Growth Resistance of Thin Mortar Layers with Hybrid Fiber by L. Sorelli, N. Banthia, and G. A. Plizzari Reinforcement . 161 SP-224-13: Modeling of Cement Based Composite Laminates i 79 by B. Mobasher SP-224-14: Effect of Crack Growth on Overall Mechanical Properties of Cement Composites . 193 by M. Boulfiza and N. Banthia vi Copyright American Concrete Institute Provided by IHS under license with ACI Licensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 03/16/2007 19:15:19 MDTNo reproduction or networking permitted without license from IHS -,-,- GFRC-30 Years of High Fiber Cement Composite Applications Worldwide by G. T. Gilbert Syxwpsk Thin, fiber reinforced cementitious products offer a useful balance of properties such as strength, toughness, environmental durability, moisture resistance, dimensional stability, fire resistance, aesthetics and ease of handling and installation. For more than 30 years, AR glass fibers have been at the forefront in the development of new applications of such products throughout the World. Glass Fiber Reinforced Concrete GFRC is a thin, cement composite based on AR glass fibers with an excellent strength to weight ratio. Extensive early laboratory work produced a test method for determining long term strength. The validiîy of this work has been proven by the large number of buildings clad with GFRC, as well as a vast range of other GFRC products, used over a this 30 year period. This paper explains the fundamental principles behind GFRC and gives examples of some of its uses. These applications range from high quality, architectural wall panels and decorative elements through to modular buildings down to low cost channel sections and utility components. New developments and techniques will also be discussed. Keywords; AR glass fibers; AR mats; AR meshes; decorative elements; durability; engineering properties; fiber cement; fiber reinforcement; manufacturing methods; modular buildings; thin cementitious products; wall panels 1 Copyright American Concrete Institute Provided by IHS under license with ACI Licensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 03/16/2007 19:15:19 MDTNo reproduction or networking permitted without license from IHS -,-,- 2 Gilbert Graham T Gilbert, CChem. MRSC is a Chartered Chemist and a Member of the Royal Socieîy of Chemistry. He is currently with Vetrotex Cem-FIL, a subsidiary company of the Saint-Gobain Group, one of the Worlds leading suppliers of building materials. Based in the UK, he has worked on the use of AR Glass fibers as a fibrous reinforcement for cement based composites and concrete for more than 30 years. During this period, he has traveled extensively encompassing all the major European countries as well as the Middle East and North America providing techno-commercial support to both new and existing manufacturers. He is also a member of the American Concrete Institute, The PrecastíPrestressed Institute and the International Glassfibre Reinforced Concrete Association. 1 .O INTRODUCTION Cement based materials have inherent defects such as flaws in the matrix due to shrinkage and debonding at interfaces. AR glass fibers in this brittle cementitious materials help to enhance the composite toughness and tensile strength by synergistically interacting with the micro cracks that develop when the composite is loaded. The AR glass fibers restrain crack opening and crack growth by effectively bridging across the micro cracks. The most common form of glass fibers, E-glass, is used as a reinforcing material in resin composites referred to as FRP. However, when E-glass fibers are exposed to portland cement based mixtures, such as mortars or regular concrete, the alkaline nature of the cementitious mixtures rapidly deteriorates the glass fiber. Because of this, AR glass fibers were developed by intrinsically modifying the chemical composition of the glass fibers such that they are inherently more chemically resistant to the alkaline nature of cementitious matrix. The actual dose rate used will determine the final composite properties with O.6kgku.m. llb/cu.yd being used for plastic shrinkage cracking of regular concrete. However, thin section 12mm 1/2” GFR Concrete will use much higher dose rates ranging from 2-5% of total weight being the normal range. Recently, dose rates as high as 15-18% of continuous filament have been used for newly developed filament wound poles. The exceptional high tensile strength of AR glass fibers imparts tensile properties to the resultant composite as well as improving its toughness and impact strength. Because GFRC has both good tensile and compressive strength as well as being lightweight with good fire properties and low maintenance, it has been used throughout the World in a wide range of applications and these will be highlighted later in this paper. Copyright American Concrete Institute Provided by IHS under license with ACI Licensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 03/16/2007 19:15:19 MDTNo reproduction or networking permitted without license from IHS -,-,- Thin Reinforced Cement-Based Products 3 2.0 AR GLASS FIBERS 2.1 General Data and Fiber Twes In order to make glass fibers resistant to the lime generated during the setting of Portland cement, zirconium is added to the glass mixture composition prior to melting and fiberising the raw materials. The added zirconium becomes part of the glass fiber molecular structure in the manufacturing process and is not just a protective coating. The minimum zirconium content in the composition for good durability is about 16% by weight. The glass fibers with this zirconium modification are usually referred to as aikaii-resistant glass fibers or AR glass fibers. AR glass fibers are chemically stable resisting both alkali and acid conditions. Chemical composition of the AR glass fibers is shown in Table 1 and the physical and mechanical properties in Table 2. AR glass fibers for use in concrete are available in three basic forms - discrete chopped strands CS, continuous rovings and meshes. 2. i . i AR Glass Fiber Discrete Chomed Strands- are used primarily in premix glass fiber reinforced concrete high dose rate and in crack control of concrete low dose rate where the glass is added directly to the cement or concrete slurry. Typically, AR glass fiber CS are available in two types, integral and water dispersible. Glass fiber CS are made up of bundles of individual filaments with the typical diameter of the
