FAQs
Click on a question below to expand and reveal the answer:
- What are Combat Concrete Shelters (CCS)?
- CCS are rapidly deployable, inflated structures that harden on hydration to form durable concrete buildings. They enable high quality permanent buildings to be constructed with comparable time and effort to temporary soft skinned structures. Installation is extremely simple and requires no heavy lift cranes and no training. The units are modular in design and so the space can be expanded to meet operational needs.
- How did the concept for CCS originate?
- The CCS was conceptualized and invented by the award winning designers and engineers of GCCM materials Peter Brewin and Will Crawford in the United Kingdom. The concept originated from the idea of using inflation to create a purely tensile surface to use as the formwork for perfect compressive forms, thus using the properties of concrete most efficiently. Combat Concrete GCCM was developed over a 3 year period and thousands of iterations, including developing a plant to produce the GCCM continuously. Research was conducted in Uganda, visiting camps in the field and interviewing refugees and 22 UN Agencies and NGOs over a 5 week period. New Orleans was also visited in the wake of Hurricane Katrina as well as a user feedback forum in Geneva with staff from the all the major aid agencies. The development has been iterative, beginning with 1/8th scale prototypes and trial samples and progressing to full scale prototyping and testing.
- How much does a CCS cost?
- Please email us at sales@combatconcrete.com if you would like information on pricing.
- What do you need to deploy a CCS?
- The building comes supplied with everything required for construction, including a full set of deployment instructions and H&S information (Annex D). Construction is extremely simple and requires only access to power for the blower unit (can be provided as 110V or 240V) and a water supply (approx 250 gallons for the CCS270 and 500 gallons for the CCS540). The water does not need to be potable, and bore-hole water, river water or seawater can be used. No major ground excavation or foundation work is required.
- What level of Force Protection does CCS provide?
- CCS are constructed using our CC13 (13mm thick) material. Although CCS will provide much better protection from fragmentation than a conventional soft skinned structure, the current version of our CC material is not designed to provide ballistic protection. However, the structures are designed to be earth bermed using an earth fill force protection system such as DefenCell or Hesco Bastion. Please refer to the manufacturers websites for details on protection levels provided by these systems. The Swedish military recently conducted blast testing on an unprotected (not earth-bermed) CCS. The results showed that CCS can withstand a bare charge of 5kg at a distance not closer than 3m.
- Have you done any analytical testing on CCS?
- In addition to the static loading trials, Combat Concrete GCCM has commissioned Finite Element Analysis of the shelter to determine the maximum loading criteria including: overhead loading, wind loading, uneven snow loading and point loading. The work was led by Dr. Antony Darby, Senior Lecturer of Structural Engineering at the University of Bath. The full reports can be viewed upon request. A summary of the analyzed conditions is below:
• Overhead Loading (based on fill density of 20kN/m3) = 800mm
• Uneven Snow Loading = 1.5kN/mm2, (equivalent to 1.5m of fresh snow).
• Wind Loading (during first 8 hours of curing) = 15m/s, (33mph).
• Wind Loading (after 24 hours) = 60m/s, (130mph).
• Point Loading (on apex of structure) = 2000N - What are the weights of each shelter variation?
- The weights of the shelters are continually dropping as we develop Combat Concrete Shelters. A basic guideline for the CCS270 and CCS540 are 4189lbs (1900kg) and 6834lbs (3100kg) respectively, significantly less than any other comparable semi-permanent and permanent structures.
- How do the shelters perform thermally?
- CCS have excellent thermal properties and have been designed to allow earth or snow berming. This provides both improved thermal insulation and a large thermal mass which helps maintain a constant internal temperature by dampening temperature fluctuations between night and day. This is especially important in desert environments where the temperature can vary from extreme heat in the day to below freezing at night.
- Can a CCS be buried or bermed?
- We do not recommend burying the shelters. However, earth or snow berming is the practice of using earth or snow against building walls for external thermal mass, to reduce heat loss and to maintain a steady indoor air temperature. CCS, when earth bermed, will also provide protection against small arms fire and shrapnel.
- What size of shelters are available?
- There are two shelter variants available with 270sqft (25sqm) and 540sqft (50sqm) of floor space (known respectively as CCS270 and CCS540). We do not supply shelters in any other sizes apart from these.
- Is it possible to repair CCS?
- Yes. Combat Concrete GCCM can be used to patch Combat Concrete Shelters as it bonds extremely well to itself. Alternatively, a standard cement mortar may be used.
- Can I put windows in CCS?
- It is possible to cut small openings in CCS provided that you do not cut through one of the reinforcing ribs which are critical in stiffening the structure. We not recommend earth berming CCS if any openings have been cut in the CC skin.
- Is it possible to connect shelters together?
- Combat Concrete Shelters have been designed as part of a modular system: units can be easily linked together enabling the space to be tailored to the application. The prefabricated units can be expanded as required, by docking units end-to-end to allow an uninterrupted flow of internal space. The double doors are reversible allowing the blades to be changed from outward opening to inward opening to facilitate docking.
- What is the lifespan of a CCS?
- CCS units have a design life of 10 years. This is based on accelerated age testing of the GCCM for a range of environmental conditions. CCS units are manufactured from 3 constituent elements, the GCCM, plastic liner and steel doors. All 3 have been independently tested to the relevant British and International Standards.
- How do you demolish a CCS?
- Combat Concrete Shelters can be demolished using simple hand and/or power tools or by conventional demolition using heavy equipment. CCS are thin walled structures. When demolished, they constitute a very small volume of debris which can be reused as hardcore in rebuilding operations.