The U.S. Army has developed a new blast-protection adhesive tape called X-Flex. This X-FLEX tape would be used to coat the interior sides of exterior walls in order to absorb the shock of a blast, protecting the occupants from flying concrete and metal turned into projectiles. Of course, such a material could also be used to protect civilians. (xflex system website)
The Engineer Research and Development Center (ERDC) is also developing a $10-million modular protective system that it claims in a promotional video is made from material “10 times stronger than concrete.” The system would allow soldiers to construct temporary structures or reinforce existing ones with walls consisting of a double layer of armored panels held together by a collapsible frame.
If the six-month project is a success, the technology could also be used in the U.S. “Uddin said that while this next phase of his fiber-composite research is taking place overseas, the technology, if it proves viable, will have tangible benefits for the coastal regions of United States, including parts of Alabama. ‘The potential payoff of this program could be the rapid insertion of the tree-fiber technology into the rebuilding and future construction of homes in the Gulf Coast states, especially in flood and storm prone areas like Mobile and New Orleans,’ Uddin said.”
Recently there was a simulated test in which the equivalent of a 15-foot piece of wood traveling at 130 miles per hour hit the less than 6-inch-thick SIP. The object barely made a dent on impact.”
A blast-wave overpressure of 5 pounds per square inch, which is associated with winds around 150 miles per hour, is enough to destroy wood-frame buildings and cause severe damage to brick apartment buildings. However, with simple and cheap construction improvements and retrofits it is possible to enable all wood-frame buildings to survive 5 PSI. Further construction improvements can increase the survivability of buildings and the people inside them.
The Hurriquake nails have been widely available since 2006. They were only available in the Gulf region. Bostich, the manufacturer, added new production lines to meet nationwide demand. The nails are used in tens of thousands of homes since 2006.
The bottom section of the HurriQuake nail is circled with angled barbs that resist pulling out in wind gusts up to 170 mph. This “ring shank” stops halway up to leave the middle of the nail, which endures the most punishment during an earthquake, at its maximum thickness and strength. The blade-like facets of the nail’s twisted-top — the spiral shank — keeps planks from wobbling, which weakens a joint. The
HurriQuake’s head is also 25 percent larger than average to better resist counter-sinking and pulling through.
For purposes of very rough estimation, it is sometimes assumed that the radius of 5 pounds per square inch overpressure defines the circle for which the number of survivors inside would equal the number of fatalities outside, taking into account all the listed effects other than fallout. This would mean that the total number of early fatalities, other than from fallout, would be estimated as the population density multiplied by the area of this circle.
If every building could survive 5PSI then there would be no building failures for category 5 hurricanes or less and potentially no deaths outside the 5PSI radius of a nuclear blast for anyone inside a building. This would reduce the casualties from a nuclear bomb by half or more.
There is a new method of handling wood fibers so that cellulose fibres are undamaged. The mechanical tests shows undamaged cellulose paper has a tensile strength of 214 megapascals, making it stronger than cast iron (130 MPa) and almost as strong as structural steel (250 MPa). This would be a cheap way to increase the strength of construction material and further reduce the fatal blast radius. If cellustic fiber provided inexpensive reinforcement up to 20PSI, then the fatal blast radius for those inside buildings could be reduced to 35%. This would be five times lower fatal area or only 20% of the casualties.
As the technology becomes available and affordable continue to increase higher levels of robustness.
Level 1: Hurriquake nails and other cheap adjustments that are widely available now and in use for some new construction. Expect to get to 2-5 PSI and up to 10-15 resistant houses. Also need treatments for improved fire resistance. 50-70% casualty reduction.
Level 2: Use cellustic fiber that is almost up to the strength of steel (nanopaper made from wood), more steel framed construction, better concrete or carbon fiber, or graphene reinforcement. Stronger windows, doors OR monolithic domes for some new construction. Resistant PSI 10-25+. 60-85% casualty reduction. Add anti-radiation damage drugs (see the bottom of this article on new carbon nanotube based drugs that are 5000 times more effective.) Total 85-92% casualty reduction.
Level 3: Better materials (more advanced carbon nanotube, graphene reinforcement with hydrogen impregnated for radiation shielding) and designs. PSI 25-100+. 85-98% casualty reduction. Need anti-radiation gene therapy and anti-radiation drugs as the radiation casualties would be dominant.
Level 4: Molecular nanotechnology. PSI 1000+.
Integration of radiation to electricity systems Integrate room temperature superconductors for strong magnetic shielding. Rapid evacuation from utlity fog systems. Metamaterials that guide earthquakes shocks and other waves around buildings. 99.9%+ casualty reduction.
Shelter in Place: Shielding by Buildings
– A brick building provides better protection than does a brick veneer building, which is better than that of a frame building.
– Multiple stories increase protection as well.
– The interior of a one-story building reduces exposure by 50 percent.
– A level below ground reduces exposure by 90 percent.
– Additional levels provide more shielding and increase the overall effectiveness above and below ground.
– The five-story building illustration, below, shows that the middle floors provide better shielding than the ground floor because fallout that covers the ground emits gamma radiation along with that on the exterior surfaces of the building.
– Moving to a higher floor in the building increases the distance from the ground source but, at some point, increases exposure from the source on the rooftop.
– The best option is to move to the center of the building away from the exterior walls (and below ground, if possible) or to a middle floor above ground.
– Note how the position in the building and surroundings affect the percentage by which exposure is reduced in various locations.
Dosage is translated to casualties on a linear scale which measures the probability of the victim dying of radiation sickness. At 250 REM, the number of deaths is assumed to be effectively zero; note that small children, the elderly, and those with existing medical problems could conceivably die at this dosage. 250 REM is sufficient to give most people mild to moderate radiation sickness. At 600 REM, death is assumed to be virtually certain, especially with the probable scarcity of medical care in the wake of an attack. Massive attacks on a small area such as a missile base can produce 600+ REM fallout up to several hundred miles away.
Medical management (treating the injured) is important to reduce fatalities. So it makes sense to harden medical facilities to 100 PSI or higher. Other facilities to harden are power generation.
Advancing technology means that weapons are getting more and more powerful and eventually more nations and groups will have access to nuclear weapons or more powerful weapons. It would foolish to assume that we must safely walk a tight rope without a safety net. A moderate increase in building costs will mean more survivable buildings that will save lives from severe weapons and warfare.
When carbon nanotubes are cheap after 2015 or so, then it will easy to increase buildings to 100-4000PSI strength while maintain most of the aesthetic look.
Nuclear weapons effects
functionalized with additional hydrogen species, the composite materials could serve as radiation protection from secondary radiation events. Imparting nanotubes into the midplane or on the surface could serve as radiation protection or as protection against lightning strikes.
Discussion of materials for shielding against ionizing radiation. The more hydrogen in the materials the better the shielding.
Lithium hydride is a popular shield material for nuclear power reactors, but is generally not useful for other functions. The graphite nanofiber materials heavily impregnated with hydrogen or any composite thereof may well represent a viable multifunctional component in future space structures. In this case study of
the graphite nanofiber, hydrogen content is ~ 68% wt while in laboratory in single-walled carbon nanotubes (SWNT) hydrogen storage has been achieved ~ 10% wt.
(1) Active (electromagnetic) shield concepts:
• Electric fields.
• Magnetic fields (attached coils).
• Magnetic fields (deployed large-diameter coils or shields bearing magnets).
• Plasma methods (expand magnetic field, produce electric field).
• Many previous studies of physics for most; some studies of engineering.
• Requires space power to develop fields; requires superconducting magnets.
• To shield against GCRs one must have either very high fields or very extended fields.
• ∫ L BXdl
> 1,000 G km or V > 10**10 V.
Proposed figures of merit/discriminators:
• ∫ L BXdl
> 1,000 G km or V > 10**10 V.
• Smallest stored energies in field.
• Minimized effects of fields on crew and equipment (