Solidification of Polymer Concrete Using the Artificial Lunar Soil

Abstract

The present study concerns a production of lunar concrete using the artificial lunar soil and thermoplastic polymeric material as binder. The lunar soil was cast with the polymer in a cubic mould (50×50×50 mm) in a lunar environment-mimic chamber. Prior to solidification of the lunar soil mixture, the chamber was evacuated by a vacuum pump to 0.1-0.2 torr, followed by preheating by an electric heater placed inner wall of the chamber to sustain the internal room temperature at 123°C. Then, a heat plate, of which the surface temperature accounts for 230°C, was attached in one dimension for 5.0 hours on the top of the specimen in the mould to melt the polymer embedded in the mixture then to bind artificial lunar soil. Simultaneously, a specimen was in the equated condition except for the preheating process; the room temperature was about 15°C at the onset of plate-heating and instead the heating duration lasted 24 hours to compensate for preheating benefit. As a result it was found that the specimen subjected to preheating was mostly solidified, of which solidified depth accounted for about 49.2 mm, whilst non-preheated specimen was only partially solidified in the vicinity of the top, where the heat plate was directly attached. It implies that preheating of the mixture would be more effective in melting the polymer and thus binding lunar soil then to form a solid body, even in a shorter heating duration. Without preheating, the melting efficiency of the polymer was marginal to solidify the lunar soil in a relatively long heating (i.e. 24 hours).