Manufacturing of Lunar Concrete by Steam

Abstract

This paper describes a method of manufacturing concrete under vacuum conditions, based on an enhancement of the Dry-Mix/Steam-Injection method (DMSI) by T. D. LIN. The aim is the production of concrete elements for the construction of modular protective structures on the moon. Due to the vacuum, manufacturing by wet mixing of cement, aggregate and water is not possible, because the unbound water would quickly evaporate. In initial experiments it was shown that the water demand for concrete mixtures with a high content of fine particles can be greatly reduced with the help of the DMSI method leading to nearly equal compressive strength in shorter hardening time. Earth and Space 2014 © ASCE 2015 274 © ASCE Earth and Space 2014 Downloaded from ascelibrary.org by RMIT UNIVERSITY LIBRARY on 08/14/15.

Dry-mix autoclaved lunar concrete from lower-Ti basalt lunar regolith simulant

“…The optimal steaming temperature for dry-mix samples of cement and standard sand is 180-200°C and the optimal steaming scenario for 10 cm 3 samples of concrete is at 200°C for 18 h. The present DM/SI method has advantages of lower cement content, shorter hardening time and higher concrete strengths, as compared to normal temperature wetmix method [8]. S. Wilhelm and M. Curbach has verified the DM/SI method with lunar regolith simulant JSC-1A, which generated a compressive strength of 10.7 N/mm² and a water-cement ratio of 0.45 was calculated after one day procedure [9]. The steam injection hydration of high alumina cement concrete (mortar) and Ottawa sand has been characterized by D M Pakulski and K J Knox in 1992, a compressive strength of about 30 N/mm² after steaming for 25 min at 130℃ and 0.2 N/mm² steam pressure was achieved [10].…”

Advantages and challenges of novel materials for future space applications

“…• Microwave sintering (Agrawal, 2006), which exploits high frequency microwaves to convert electromagnetic energy into thermal energy, used to process ceramic materials and metallic powders. • Dry-Mix/Steam-Injection (DMSI) (Lin et al, 1996) and Enhanced Dry-Mix/Steam-Injection (E-DMSI) (Wilhelm and Curbach, 2014), for the manufacturing of concrete products with good compressive strength by means of exposure to high temperature vapors. • Quench Module Insert (QMI) and Diffusion Module Insert (DMI) (Carswell et al, 2003), which are ovens designed to operate on metals and alloys in the 400 °C-1600 °C temperature range, under reduced gravity.…”