1、COPYRIGHT ACI International (American Concrete Institute)Licensed by Information Handling ServicesAC1 SP-125 91 m Ob62949 0022072 3 m Lunar Concrete Richard A. Kaden Editor SP-125 COPYRIGHT ACI International (American Concrete Institute)Licensed by Information Handling ServicesA61 SP-125 91 Obb2949
2、0022073 5 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 December 1, 1991. AU discussion approved by the Technical Ac
3、tivities Committee along with closing remarks by the authors wiii be published in the May/June 1992 issue of either AC1 Structural 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
4、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 i
5、n the subject areas of the papers. Copyright 1991 AMERICAN CONCRETE INSTITUTE P.O. Box 19150, Redford Station Detroit, Michigan 48219 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
6、 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. Printed in the United States of America Editorial production Victoria Luni
7、ck Library of Congress catalog card number 71712 COPYRIGHT ACI International (American Concrete Institute)Licensed by Information Handling ServicesAC1 SP-125 91 H 0662749 0022074 7 H PREFACE That concrete might become a primary material of construction, versatile, and inexpensive for use on the Moon
8、, would at first seem to be an outrageous idea. After all, the Moon is naturally a very dry place, drier than the driest terrestrial desert, with the nearest water hole 250,000 miles away, and the Moons surface is enveloped in an almost perfect vacuum. This is an unfamiIiar environment for the produ
9、ction and use of a water- containing material like concrete. However, a small group of scientists and engineers, many of them represented in this collection of papers, have perservered in examining the outrageous premise, and perhaps the idea is not as strange as it might have initially seemed. Most
10、, perhaps all, of the materials needed to make concrete are naturally present on the lunar surface. Although they have to be extracted and transformed, the energy required to do that, and probably the cost, is much less than that which would be required to bring the same quantity of material from Ea
11、rth to use on the Moon. And the technology for utilizing these natural materials of the Moon would appear to be straightforward modifications of techniques that have been developed for terrestrial applications. It is that technology modification and adaptation to the lunar environment that is the su
12、bject of these papers. But the development of lunar concrete into a viable material to be used on the Moon is of much broader importance than just an interesting study in technology modification and applicafion. It is a paradigm for the Space Exploration Initiative, a bold announcement made by Presi
13、dent George Bush on July 20th, 1989, that the US. would return to the Moon, “this time to stay.“ The lunar concrete development represents a challenge to conventional thinking, both on Earth and for Space. That challenge will excite a few young students who might otherwise have taken non-technical d
14、irections in their life to work in civil or chemical engineering, to break new and unique ground as they apply their intellect to these new problems. And in space, the traditional approaches of engineering space habitats will likewise be challenged by a new generation of engineers and iii COPYRIGHT
15、ACI International (American Concrete Institute)Licensed by Information Handling ServicesAC1 SP-125 91 = 0662949 0022075 9 = scientists, who will have more tools to work with than their predecessors. And this is only one small area of technical practice. Multiplied by the many disciplines that will n
16、eed to be involved in the Space Exploration Initiative, the challenge of the Moon, and Mars, will energize a new generation of young people to think new thoughts and achieve greater heights than did the previous generation. The papers contained in this volume are only initial steps in the process of
17、 understanding whether to use concrete on the Moon can fulfill the promise of decoupling the Moon from the Earth, moving the mine, mill, and water hole 250,000 miles up and out of the Earths gravity weil, and freeing a lunar outpost from dependence on the Earth for its construction materials. Howeve
18、r, they are essential to the process, and are laying the basis for much more work that will certainly follow. Michael B. Duke Lunar and Mars Exploration Program Office National Aeronautics and Space Administration Houston, Texas August 23, 1990 iv COPYRIGHT ACI International (American Concrete Insti
19、tute)Licensed by Information Handling ServicesAC1 SP-L25 91 m 0662949 0022076 O m FOREWORD The mission of the AC1 125 Committee is to develop and correlate knowledge and formulate recommendations for concrete construction on the Moon. This symposium volume contains the first series of papers dealing
20、 with the topic. The papers address cement production, concrete mixes, structural concepts, concrete placement, and the lunar environment. Mans earlier exploration of the Moon during the Apollo program involved brief sorties from the flight vehicle, which served as the astronauts lunar habitat. One
21、of the objectives of the Space Exploration Initiative (SEI) is to establish permanent outposts on the Moon. These outposts will require permanent facilities. Ideally, these facilities can be construcfed with maximum utilization of indigenous materials, such as lunar concrete. The American Concrete I
22、nstitute, through its 125 Committee, encourages the study of topics that will assist in the development of lunar concrete application in support of SEI. I hope you find this volume to be both challenging and interesting, perhaps kindling an interest in a lunar concrete study of your om. Richard A. K
23、aden AC1 Committee 125, Lunar Concrete Symposium Editor V COPYRIGHT ACI International (American Concrete Institute)Licensed by Information Handling ServicesAC1 SP-125 91 W Ob62949 0022077 2 a COMMITTEE CHAIRMANS REMARKS The development of worldwide space programs could not have proceeded thus far wi
24、thout the participation of certain elements of concrete engineering, which have not traditionally been encompassed by the aerospace industries. Although concrete professionals have never been in the front line of aerospace development, they have played key roles in construction of ground support fac
25、ilities for most of the existing space programs. In response to the LunarMars initiative announced by President Bush, the National Aeronautics and Space Administration (NASA) established a LunarMars Program Office in March 1990 to coordinate strategies for building bases on the Moon and ultimately,
26、a journey to Mars in the early 21st century. The proposed lunar base cannot be practical without construction of facilities for habitats, resource processing, storage tanks, lunar surface transportation support systems, launching pads, and others. Manned bases on the Moon will require structural mat
27、erials capable of resisting a differential pressure of one atmosphere, solar wind, micro- meteoroids, and temperature extremes. Small structures for outposts envisioned for the early stage of lunar development may be fabricated on Earth and subsequently transported to the Moon. But, large structures
28、 suitable for industrial operations must be constructed using in situ lunar materiais. A potential material for such construction is concrete because of its capability to resist the harsh lunar environment, and because it can be produced from lunar materials, with the exception of hydrogen for water
29、 production. Two viable formulations for cements using simulated lunar anorthite and basait have been developed in 1990. Paste cubes made with these new cements developed compressive strengths of 39 MPa (5,500 psi) and 49 MPa (7,100 psi), respectively. Previous tests performed on mortar cubes made w
30、ith Apollo 16 lunar soil exhibited compressive strength in excess of 75 MPa (10,000 psi). Vi COPYRIGHT ACI International (American Concrete Institute)Licensed by Information Handling ServicesI AC1 SP-125 91 W Obb2942207B 4 = An ongoing investigation on a dry-midsteam-injection concreting procedure i
31、n a vacuum environment may provide a practical solution for the casting of concrete on the Moon. All of this fundamental research has been and is currently being carried out by members of American Concrete Institute (ACI) under NASA sponsorships. It is expected that as the aerospace industry begins
32、to examine these new opportunities, concrete, for its versatility, may become the most technically and economically feasible material for construction in space. The inclusion of concrete in space programs will broaden the constituent base of the concrete industry and add new dimensions to ACI. Now i
33、s the time for the concrete industry to be actively inolved with space programs. The newly established Lunar Concrete Committee (ACI- 125) signifies the commitment of AC1 to join with the aerospace industry in the development of new technologies to meet new challenges of the 21st century. At the req
34、uest of the Steering Committee of the Lunar Concrete Committee, Mr. Richard Kaden has accepted the responsibility of organizing the symposium and compiling this symposium volume, which he has carried out alone on a voluntary basis. On behalf of the entire committee, I would like fo extend special th
35、anks to Dick for a job well done. T.D. Lin, Chairman AC1 Committee 125, Lunar Concrete vii COPYRIGHT ACI International (American Concrete Institute)Licensed by Information Handling ServicesAC1 SP-125 91 0bb2949 0022079 b EDITORS NOTE As you read this AC1 125 Lunar Concrete Symposium volume, please k
36、eep in mind that this is the first of a series of papers that deal with lunar construction. The mission of this committee is to: Develop and correlate knowledge and formulate recommendations for concrete construction on the Moon. Six American spacecrafts, carrying two astronauts each, landed on the
37、Moons surface between 1969 and 1972. Much of this scientific data obtained during these missions has been used to form the basic logic incorporated in many of these papers. The cover of this volume suggests an idealized flight path as a prerequisite for landing on the Moon and a return to Earth. Spa
38、ce Station Freedom, which will be constructed in the future, was omitted from this illustration because of scale. Our AC1 logo, encompassed between the Earth and the Moon, depicts the international status of our AC1 125 Lunar Concrete as truely an international committee. The Moon is shown as full a
39、nd the primary landing site was selected at random. As a brief primer for the Moon, a short discussion will follow to kindle your interest in this basic object within our Solar System. The Moon is about one-fourth the size of the Earth and has a diameter of 2,160 miles (3,476 km). The average center
40、 to center distance from the Moon to Earth is 239,000 miles (384,500 km). If observed from space, the Moon orbits the Earth every 27 1/3 days, in a path that is less than 6% out-of-round. As the Moon orbits around the Earth, the Earth moves around the Sun. Both the Earth and the Moon are traveling t
41、ogether and therefore it will take the Moon about 29 1/2 days to reach a similar position in our sky. After inventing the telescope in 1610, Galileo discovered that the Moon had smooth and dark areas. He named the dark areas lunar seas, maria, even though there is no water in the depressions. A sing
42、le sea is a mare, pronounced “MAH-ray“. As the Moons phases change from thin crescent (new Moon), to the waxing crescent, to first quarter, to waxing gibbous, to full, to waning gibbous, and to third quarter we on Earth see a changing Moonscape. As the Moon rotates around the Earth, it also rotates
43、on its axis so that we see approximately the same half of the Moon surface. Also, half of the . v111 COPYRIGHT ACI International (American Concrete Institute)Licensed by Information Handling ServicesL. AC1 SP-125 91 m Ob62949 0022080 2 m I Moons surface is always iighted by the Sun. The half of the
44、Moon that is lighted is a part of the surface that we see. The backside of the Moon is a part of the surface that we never see, except when photographed by orbiting missions. A new Moon or dark part of the crescent Moon can sometimes be seen as an “Earthshine“ when light from the Suns rays hits the
45、Earth and is reflected back to the Moon. The Moons phases directly Muence the temperature of the lunar surface and vary from about -250 degrees F (-130 degrees C) to +250 degrees F (130 degrees C). Other useful constants may include: the eccentricity of the Moons orbit is O.O54g, the Moons gravity i
46、s about 1/6th of the Earths, the Moons surface area is 4.087 x 1E+15 ft2 (3.797 x 1E+8 km?, and the escape velocity at the surface is 7.79 x 1E+4 ft/s (2.375 x 1E+4 m/s). As an introduction to the Lunar Concrete Committees composition, please refer to the July 1990 issue of Concrete International an
47、d the articIe entitled The Moon and “Back To The Future“, within the section Concrete: Yesterday, Today, (2) prestressing procedures and anchorage systems; (5) transportation of materials and structural elements; (4) construc- tion methods, connection of ele- ments, and planning; (5) sealants, maint
48、enance, logistics, and struc- tural safety; and (6) scheduling, en- ergy requirements, labor require- ments, costs estimates, and quality control. Lunar education - Philip J. Richter, chief structural engineer, Advanced Technical Division, Fluor Daniel, Inc., and Menashi D. Cohen, associate professo
49、r, School of Engineering at Purdue Univer- sity, Co-chair this important sub- committee. The education groups aims and missions are to assist in assuring an interchange of infor- mation between all subcommittees and provide liaison with profes- sional organizations and agencies. They will promote activities to pro- vide information and gain public interest and support, including new entries into the field, through semi- nars, symposia, workshops, and ar- ticles of interest for news releases and media coverage. The co-chair- persons will stimulate and coordi- nate partic
