.Tung Dju (T. D.) Lin, a materials scientist, believes this will be possible merely by adding hydrogen to moon rocks. If he is right, it means that the only thing that will have to be taken from Earth is the hydrogen, possibly in the form of liquid methane or liquid ammonia. Dr. Lin said that taking volatile liquid hydrogen would be too dangerous.
.President George Bush announced in July 1989 a project to send men back to the moon to set up a base there from which to launch a manned mission to Mars. Mr. Bush predicted the base will be operational by the year 2005.
.The Taiwanese-born Dr. Lin, who works for the Portland Cement Association in Chicago, heads an industry group called the Lunar Concrete Committee. He gave a lecture at the Palais de la Découverte in Paris recently at the invitation of Lafarge New Materials, the only European member of the committee.
.Dr. Lin has proposed building a circular base on the moon requiring 1,000 tons of cement, 330 tons of water and 360 tons of iron reinforcing rods.
.Carrying that amount of material from earth at an estimated $50 million a ton would be prohibitively expensive. So Dr. Lin started looking for a lightweight solution.
.The National Aeronautics and Space Administration gave him a 40-gram sample of moon rock, from which he deduced that everything needed to build concrete bases already exists on the moon.
.The lunar surface is rich in a material called ilmenite, containing iron oxide and titanium oxide. Heated to 800 degrees Centigrade (1,176 degrees Fahrenheit), ilmenite combines with hydrogen to produce iron, titanium, oxygen and steam. Dr. Lin said that the process also could be used to produce the water and oxygen needed for human survival.
.The crushed lunar rocks would produce a fine, lightweight and extremely strong cement. And the left-over iron could be used to make reinforcing rods. Dr. Lin said it would be easy to draw out the rods in the low gravity of the moon's surface.
.In 1984, NASA sent up a satellite on a six-year mission to test the feasibility of dozens of materials that might be used to build a lunar base. Concrete was not one of them because no one at the time thought it could be a practical solution. The experiment showed that all the materials were affected by solar radiation and the hammering of space particles.
.Dr. Lin believes that concrete may be the only material capable of withstanding the harsh conditions on the moon. He said lunar concrete would be similar to the material that makes up asteroids, which have survived in space for billions of years. It would have to withstand not only the bombardment by solar rays but also enormous temperature extremes.
.Using his tiny supply of moon rock, Dr. Lin produced a slab of concrete that he said was superior in strength and elasticity than the finest materials used in civil engineering on earth.
.Dr. Lin believes he also has solved the problem of how to mix the cement, the aggregates and the water in an environment lacking atmosphere. He made cubes of dry cement and passed steam through them for 18 hours. The result, he said, was a concrete that was more than twice as strong as that made by conventional means and cured for a month.
.D.R. Lin said that heat needed to carry out these processes would be obtainable from solar panels. Experiments are taking place around the world to perfect methods for carrying out the process. The University of Chicago is working on the solar panels and methods for heating up the lunar rocks. The Shimizu Corp. in Japan is seeking a method of crushing the lunar material into a fine powder. Lafarge is working on the development of concrete structures without water.
.Dr. Lin said each kilogram of concrete would require only 3 grams of hydrogen. The manufacture of concrete on the moon's surface, he said, would require only about 200 tons of machinery and drilling equipment.