International Concrete Abstracts Portal

The moon offers a stable platform with excellent visual conditions for astronomical observations. Some troublesome aspects of the lunar environment must be overcome to realize the full potential of the moon as an observatory site. Mitigation of negative effects of vacuum, thermal radiation, dust, and micrometeorite impact is feasible with careful engineering and operational planning. Shields against impact, dust, and solar radiation must be developed. Means of restoring degraded surfaces are probably essential for optical and thermal control surfaces deployed on long-lifetime lunar facilities. Precursor missions should be planned to validate and enhance the understanding of the lunar environment (e.g., dust behavior with and without human presence) and to determine environmental effects on surfaces and components. Precursor missions should generate data useful in establishing keepout zones around observatory facilities where rocket launches and landings, mining, and vehicular traffic could be detrimental to observatory operation. If lunar concrete becomes available, it could be a material of choice for observatory foundation construction. For concrete to be a viable choice, its production and use must be compatible with the observatories' needs for clean, precision optics, and for an environment free of dust, shock, vibration, and outgassing. It must also be economically competitive with alternative construction techniques.

It has been proposed that a large pressurized shirt sleeve environment assembly facility would be useful during all phases of lunar outpost development. This article discusses the use of such a facility during later phases of outpost development when use of native materials is maximized. The principle benefits from the use of a large pressurized facility are that workers needn't wear cumbersome, restrictive space suits and concrete needn't be cured in the vacuum environment of the moon. A specific assembly facility concept is presented and its conversion to a lunar precast concrete plant is discussed.

Early in the next century, humans will return to the surface of the moon for stays of increasingly longer duration. Many civil engineering challenges must be addressed so that these twenty-first century pioneers will have the shelter and life-support systems needed to survive and thrive in a largely benign but, in some ways, hostile environment. Depending on the stage of the lunar presence, different structures and processes will be feasible. Reliance on lunar resources, including manufactured forms such as lunar concrete, will become more important as the base size and maturity grows. It is the task of the universities in these endeavors to provide the basic knowledge to help meet these challenges and to produce enthusiastic and well-prepared graduates who can best continue to develop the solutions needed to support the expansion of humans into space. Educational programs in space civil engineering now undergoing development at Colorado State University under a NASA space grant college program are described. An undergraduate option that supplements the existing civil engineering program through a cluster of classes that can be taken within the existing elective structure is being developed. Concepts for an MS graduate program are also outlined.

This paper suggests establishing the applicability and manufacturing technique of GFRP, particularly dimethylisophtalate glass-filament rod. The use of GFRP reinforcement in lieu of conventional steel rods and wires has great potential for precast structural concrete elements. GFRP may be cheaper, lighter, and formed from materials found in abundance on earth and on the moon, namely silica (SiO2). GFRP can be manufactured with the same, if not higher, tensile properties of steel. If synergically composed with a plastic carrier, a new science in construction and structural analysis could be born. No doubt remains that lunar soil is cementitious. Rocks for aggregate and silica are also abundant on the moon. Heavy fabricated steel rods are counterproductive for transport to the moon. Glass fibers fabricated on the moon have great potential. Permanent settlement/habitats on the moon are within the realm of possibility and may be considered immediate projects. Therefore, the idea of using local materials is appropriate within the concept of a third phase of permanent underground reinforced concrete construction facilities, the first being the Apollo landings and the second a temporary above-ground lunar establishment yet to come. This analysis could lend itself not only to permanent reinforced concrete structures on the moon, but to any other planet where silica is abundant and cement could become a local product, through refining and reducing appropriate local ores. Manufacture of glass-fiber filaments is incomparably cheaper than steel. Additional research, at a later date, will encompass the application of pre- and post-tensioned GFRP reinforcements, using the same structural form elements. This paper proves the positive applicability of GFRP as reinforcement for precast concrete elements.

Provides an overview of engineering studies performed in support of the Space Exploration Institute (SEI). Topics addressed include background on the SEI, lunar construction phases, lunar habitats, lunar oxygen, mechanical concepts, and lunar power. Although the topics do not relate equally to concrete construction, they do identify selected issues that must be addressed before a lunar outpost can evolve to the emplacement and operation phases. In these phases of lunar outpost development, maximum use will be made of native materials, such as lunar concrete.