Design of Sifcon / Alternative Material for use in Underground Reinforced Hardened Shelters
The underground shelters which are subjected to heavy transient blast loading requires suitable material of construction which should possess higher tensile strains, higher energy absorption and better ductility characteristics. To achieve the above requirement, the conventional concrete requires large thickness and heavy reinforcement, which will lead to increased weight and other problems related to handling and erection. This has been overcome by use of SIFCON material and the study has been successfully demonstrated at laboratory level.
Slurry Infiltrated Fibrous Concrete (SIFCON) structural elements possess better properties as compared to their counterparts built using conventional reinforced concrete. The main focus of the study is to throw more light on the design and construction aspects of underground reinforced hardened shelters, using SIFCON. Construction of underground hardened shelter requires prefabrication of various structural components at factory for better quality control. For transporting these structural components to the required site, weight of each element is a major concern.
- Use of SIFCON resulted in complete elimination of reinforcement and also in significant reduction in the thickness of the shell.
- Special test instrumentation and loading arrangements have been designed and used for testing circular and hairpin geometry.
- The innovative idea of using SIFCON has resulted in better performance against blast loading and increased ductile behaviour.
- Even though initial costs may be higher for SIFCON, owing to its better structural performance, reduced handling and erection cost, its cost/benefit ratio is higher.
- Circular SIFCON specimens showed higher post peak response when compared to hairpin SIFCON specimens hence was recommended.
- The under ground shelters designed using the proposed SIFCON technology are better suitable for housing control & command facilities near airports and for other strategic defense institutions.
