Thermal Studies of HEMSS Cylindrical Test Beds Containing SRI-RMG-2C4 Grout.

Abstract : Large cyclindrical test beds 2.13 m (7 ft) in diameter and cast from SRI-RMG-2C4 grout were used by Merritt CASES, Inc,. and Physics International Company to investigate the simulation of nuclear test effects on deep-based structures in the 'High-Explosive Model Structure Simulation (HEMSS) Program.' 2C4 grout was used in the test beds and reached temperatures in excess of 108 degrees C (226 degrees F) in HEMSS No. 1 and 2 cylinders. Although the grout properties were well documented, the effects of heat of hydration on the grout when cast in large volumes were unknown. Thermal studies of the HEMSS cylinders were conducted at the U.S. Army Engineer Waterways Experiment Station (WES) based upon computer simulations. These studies were conducted to determine the thermal response of 2C4 grout placed in mass. The study showed that the finite-element method temperature simulation program in use at WES could predict temperature distribution in the HEMSS cylinders as a function of time after casting. Temperature in the 2.13-m (7-ft) diameter cylinders could only be effectively controlled by lowering the placement temperature of the grout. Simulations of 3.66- and 6.10-m (12- and 20-ft) diameter cylinders indicated increasing peak temperature and thermal strains as cylinder diameter increased. With conditions similar to those of the HEMSS N0. 3 cylinder, a 6.10-m (20-ft) diameter cylinder is predicted to reach a peak temperature of 116 degrees C (240 degrees F). It is recommended that additional work be done to document the properties of 2C4 grout when cured at temperatures at or near 100 degrees C (212 degrees F).