Rapidly Deployable System Including a CSA Gunite Material for the Structural Stabilization of Shock Damaged Structures

Abstract

The University of Kentucky Center for Applied Energy Research (CAER), Minova USA Inc. and the University of Dundee, Scotland, have collaborated on a project to develop a rapidly deployable system to stabilize shock damaged structures to avoid catastrophic failure. The system comprises a dry-gunned or “gunite” apparatus that sprays a mixture of rapid-hardening cement, sand and water onto a damaged surface. The cement component is based on calcium sulfoaluminate (CSA), and is capable of achieving structural strengths within 15 to 30 minutes. The project research began with a performance comparison of commercially available CSA cements. After determining which cement exhibited the best performance, an extensive research program was initiated to quantify and optimize the effects of variables including water content, aggregate content and gradation, and ratio of cement toaggregate. The experimental results produced a sprayed concrete mix that exceeded expectations in performancebetween 15 minutes and 24 hours after spraying. Achieving structural strengths within 15 to 30 minutes allowsfirst responders to enter into damaged buildings with less fear of a collapsing structure