ACI SP-202-2001 Sustainable Development of Cement and Concrete《水泥和混凝土的可持续性发展》.pdf

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1、2001 THIRD CANMET/ACI TROISIME CANMETIACI INTERNATIONAL SYMPOSIUM INTERNATIONAL SUSTAINABLE DEVELOPMENT OF CEMENT AND CONCRETE DVELOPPEMENT DURABLE DU CIMENT ET DU BTON EDITOR V. M. MALHOTRA REDACTEUR EN CHEF Front cover photo: An architectural rendering of San Marga Iraiban Temple in Kauai in the H

2、awaiian Islands, U.S.A. The temple will be built on a raft foundation of non-reinforced concrete containing 55 percent ASTM Class F fly ash. Photo courtesy of Wilbert S. Langley, W. S. Langley Concrete and Materials Technology, Inc., Sackville, Nova Scotia, Canada. Third CANMET/ACI International Sym

3、posium on Sustainable Development of Cement and Concrete Sponsored by Committee for the Organization of CANMET/ACI Intemational Conferences (AC1 Council) Ottawa, Canada International Centre for Sustainable Development of Cement and Concrete (ICON/CANMET) Natural Resources Canada Ottawa, Canada Ameri

4、can Concrete Institute Farmington Hills, Michigan, U.S.A. Institute for Research in Construction National Research Council Ottawa, Canada Editor V. M. Malhotra m international - SP-202 DISCUSSION of individual papers in this symposium may be submitted in accordance with general requirements of the A

5、C1 Publication Policy to AC1 headquarters at the address given below. Closing date for submission of discussion is December, 2001. All discussion approved by the Technical Activities Committee along with closing remarks by the authors will be published in the MarcWApril 2002 issue of either AC1 Stru

6、ctural Journal or AC1 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

7、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 2001 AMERICAN CONCRETE INSm P.O. Box 9094 Farmington Hills, Michigan 48333-90

8、94 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 retrie

9、val system or device, unless permission in writing is obtained from the copyright proprietors. Printed in the United States of America Editorial production: Bonnie L. Gold Library of Congress catalog card number: 2001092471 ISBN: 0-8703 1-041-0 PREFACE The AC1 Council for the Organization of CANMET/

10、ACI International Conferences on Concrete Technology in association with International Centre for Sustainable Development of Cement and Concrete (ICON), Natural Resources Canada, and Institute for Research in Construction/National Research Council, Canada, is pleased to sponsor the Third CANMET/ACI

11、International Symposium on Sustainable Development of Cement and Concrete in San Francisco, U.S.A., September 16-19, 2001. The first two symposia in this series were held in Ottawa, Canada, October 21-23, 1998, and Hyderabad, India, February 9-1 1, 1999. For this symposium more than 100 papers from

12、20 countries were received, and peer reviewed in accordance with the policies of the American Concrete Institute; 29 were accepted for publication. The accepted papers deal with all aspects of concrete technology and sustainability with the majority of them dealing with the role of supplementary cem

13、enting materials in reducing CO2 emissions. In addition to the papers that have been published in the referenced proceedings, more than 30 other papers were presented at the symposium. A number of these were published as supplementary papers in a separate volume, and the authors of these papers are

14、encouraged to publish these in technical journals of their choice. It is hoped that this symposium has brought to the attention of the civil engineering community the high CO2 emissions released into the environment in the manufacturing of portland cement, and the potential of reducing these emissio

15、ns by increasing the use of supplementary cementing materials such as fly ash, granulated blast-furnace slag, and rice-husk ash. The technologies are now available that, when used properly, can replace up to 60% of portland cement by these supplementary cementing materials in concrete, while maintai

16、ning or enhancing most of the mechanical and durability properties of the concrete produced. With world-wide availability of fly ash 600 million tonnes per year, the civil engineering community is well placed to use this resource to enhance considerably the supply of cementing materials without expa

17、nding the portland-cement-clinker capacity. This will not only help in reducing the CO, emissions but will also help in resolving to a great extent the fly ash disposal problem. Thanks are extended to more than 10 members of the review panel that met in Acapulco, Mexico, in December 2000 to review t

18、he papers for this symposium. Without the dedicated efforts of the reviewers, it would not have been possible to have the proceedings ready for distribution at the symposium. The co-operation of the authors in accepting reviewers? suggestions and revising their manuscript is greatly appreciated. The

19、 help and assistance of A. Bildeau (Chairman), B. Fournier,. and R. Chevrier (members) of the slide review panel are gratefully acknowledged. Thanks are extended to H. S. Wilson, M. Venturino, and G. D. Brearley for their help in processing the manuscripts. The contributions of the AC1 staff are als

20、o recognized. V. M. Malhotra, P.Eng. Editor, chairman, Third CANMET/ACI International Symposium bn Sustainable September 16-19,2001 Development of Cement and Concrete IV Intemational Organizing Committee Third CANMET/ACI International Symposium on Sustainable Development of Cement and Concrete San F

21、rancisco, U.S.A. September 16 - 19,2001 Chairman Mohan Malhotra CANMET Ottawa, ON Theodore (Ted) Bremer University of New Brunswick Fredericton, NB Wilbert (Wib) Langley W.S. Langley Concrete cement; concrete; durability; economics; emmisions; factor 1 O; pozzolan; rice husk ash (RHA); strength; sus

22、tainable development 1 2 Horton Robert trorton is CEO and Chairifiari of Alchemix Coiyoration, an ash utilization and beneficiation company focused on cement additives, with subsidiaries RHA Technologies, HZ Technologies Corporation and. Pittsburgh Mineral and Environmental Technologies. Mr. Horton

23、has served as executive management in the development of energy and environmental technologies for over 20 years. INTRODUCTION At a conference held in Beijing, China in 1996, world experts on the environment and environmental technologies discussed various challenges facing the country and an impres

24、sive array of options to address them. After three days of deliberation, the Chinese official in charge of the conference gave his concluding remarks beginning with acknowledgement that a great many good ideas had been presented that should be implemented and, taken together, would make a measurable

25、 impact on the environment in China and in the world. Unfortunately, he said, most would not be implemented because they represented cost rather than profit and, in a developing country like China, capital resources would almost dways be allocated first to projects with potential to rapidly develop

26、the economy. He told the conference attendees that if they hoped to see their ideas implemented, they must be sold based on economic, rather than environmental benefits. Specifically, he suggested that the only way to sell environmental solutions in China was to be able to say and prove to a potenti

27、al user, I have a secret way to save you money. The point made is generally true, not only in China, and embodies 2 central theme of this paper. To make any industry greener, the case must first be made that the environmentally fnendly solution will be more economically profitable. This premise most

28、 certainly holds true for the cementkoncrete industry. It is entirely within our reach, however, to make vast environmental improvements hand in hand with healthy profits. In fact, this paper outlines a factor 10 improvement in the amount of environmental disturbance created by the production and us

29、e of cement (1). Put simply, we have it within our power to arrest environmental degradation due to cement to one-tenth of the current level. The factor ten reduction can anti will be achieved. Competitive market forces will drive positive environmental changes because we have the knowledge right no

30、w to make concrete formulations based on high-pozzolan content cements that are cleaner, greener, more durable and longer lasting. Not oniy do such formulations currently exist, they have been tested, proven and advanced over several years in technical papers by researchers in concrete technology, n

31、amely, Mehta, Malhotra and others (2, 3). Sustainable Development of Cement and Concrete 3 The futurist Uuckminstcr Fuler theorized that ir tcok 25 years for a systemic change to be integrated into common use (4). Even when the idea is recognized by experts, a period of time is required to overcome

32、the inertia of the marketplace and to make the necessary investments and marketing and operational changes. We have reached such a threshold. For more than two decades those on the cutting edge of concrete technology have touted the rich benefits of pozzolanic cement additives. The drawbacks of pozz

33、olans have been largely overcome and the lines of resistance to their use are now crumbling. The transition to these more durable, environmentally sustainable concretes is underway. It will be made profitably by market leaders while those committed to conventional or environmentally insensitive prac

34、tices will be left behind. THE CHALLENGE Before going further, it is important to take stock of our present situation and forecasts for the future. Current projections estimate world population increasing from todays six billion to nine billion by 2050 and to eleven billion by the end of the century

35、. Providing basic requirements for a population nearly double that of today will intensely niagnifi pressure for food, water, land, resources, energy, goods and services. As humans struggle to survive, so too the life support system will struggle to endure. i 1 Of course, to imply that humans aspire

36、 simply to survive is misleading. for a better life. Moving toward the prosperity such as that enjoyed by many citizens of developed countries - home ownership, luxury automobiles, expansive entertainment and media, access to excellent health care, travel, the I What most human beings, in fact, aspi

37、re to is not survival but rather aspiration I I freedom of wealth - this is the stuff of the human dream. With the profusion of worldwide information, even the poorest villager in the most remote settlement l is aware of the stark contrast of lifestyle available to him or her compared to citizens of

38、 more prosperous countries. Unfortunately, accelerating waste- producing consumption is the rule in both developed and developing nations. In a world increasingly influenced by free markets and more democratic political systems, rising expectations in the developing world must be addressed by govern

39、ment actions that produce visible and tangible improvement quickly, else those populations will support the rise of other leaders promising faster growth. In short, the developing world must and will develop. in this relentless upward push, the environment will be stressed for resources to make it h

40、appen. Even at current levels of human activity, virtually every expert observer agrees on the long-term lack of sustainability inherent in our present use of energy and resources, and the attendant degradation of air, water, soil and climate. Already we are depleting, without adequately restoring,

41、4 Horton Sic fiaturai resources such as fish, forests, arable hid, fresh water and clean oxygen-rich air at a rate and in ways that will diminish the quality of all life, including that of the most affluent human beings. In virtually all of the major cities of the world, air available to both the mo

42、st and least fortunate is equally lacking in oxygen and contaminated with particulate and toxic gases. Increased occurrence of extreme weather events, such as super tornadoes, floods, typhoons and hurricanes, which most experts link to global climate change, devastate rich and poor alike. Worldwide,

43、 environmental degradation is well recognized and, particularly in richer nations, governmental regulations as well as voluntary measures are increasingly enacted to minimize the negative environmental impact of our lifestyles. Unfortunately, many such programs are poorly conceived and have minimum

44、effect. An exception has been the recycling of aluminum in the US. Even with the success of this recycling program, however, American consumers and industry still throw away enough to rebuild the countys entire commercial airfleet every three months (5). While everyone wants a clean environment for

45、themselves and their families, those who have not first met basic needs cannot be expected to take the time and effort to be environmentally responsible unless that responsibility carries with it a near term economic reward. In less developed countries, environmental policy must be shown to make mon

46、ey if it is to succeed. Herein lies the challenge: the reconciliation of societal aspirations with the planets ability to support them. Meeting this challenge is at the heart of the concept of sustainable development. This central goal of sustainable development is one of the supreme imperatives of

47、our time. It requires significant advances in basic knowledge, in the social capacity and technologies to implement what we know and in the political will to aggressively support sustainable development wherever and whenever possible. However, even if intentions are the best, laws are passed and the

48、 population is educated, history has taught us that environmental-friendly enterprises will not be sustained just because they have long-term planetary benefit. Sustainable development, if it has any hope of realization, will be achieved only if those who must support it will also realize current ec

49、onomic gain for their efforts. Proceeding from this premise, let us examine the situation in the cement and concrete industry. Concrete is the most widely used building material in the world using more than 1.4 billion tonnes of cement in 1999. The production of portland cement is one of the most energy-intensive and polluting of any industrial processes. Eight percent of all COZ released into the atmosphere due to human activity is directly associated with portland cement production (6). Suffice to say that our industry is not yet a poster candidate for sustainable development,