Heat of Hydration of Pure Cement Compounds with Steam

This paper presents test data on heat evolved by exposing cement and its compounds, tricalcium silicate (C₃S), dicalcium silicate (C₂S), tricalcium aluminate (C₃A), and tetracalcium aluminoferrite (C₄AF), individually to a pressurized steam environment for 6 hours. It also reveals morphological characteristics of their hydrates. For example, a 209 cal/g of hydration heat was measured for the pellet specimen made with the C₃S compound. It is about 90% more than that of the same compound mixed with water. All specimens hardened, except C₃A which reacted very rapidly with steam and registered an 91°C temperature rise during the test. This paper also discusses the effects of particle sizes and compaction on heat evolution in the steaming process. The test results verify the validity of the Dry-Mix/Steam- Injection (DMSI) concept which, in our judgment, will pave ways for concrete construction in outer space after the turn of century.