Coating Protects Structures Up To 20x Explosion Forces

Coating Protects Structures Up To 20x Explosion Forces

Blast and explosion mitigation has come a long way from thick concrete and metal housings. New research into granular-filled panels and metal foams have taken the spotlight in some material research circles, but these energy dissipative techniques can be disruptive to the structure or system that is being protected.

The Office of Naval Research, beginning in 2000, has funded ongoing research to develop stronger, blast mitigating options for ship hulls after the attack on the USS Cole. The research objective focused on solutions to “[…] avert rupture from a close-in underwater explosion […]”. The result was the discovery of a high tensile strength to weight ratio polymer given the name Energy/Explosion Resistant Coating or ERC.

A demonstration from GLS Coatings Ltd of a polyurea coating used on an improvised concrete block wall. The front face of the wall was coated in ERC, and the back was left dry. Although the uncoated blocks did shatter and throw projectiles, the front stayed solid. If applied to the entire wall, the internals may fracture, but the structure will remain standing and the impact force would be dissipated.

Caption from YouTube Video - “This video shows breeze-blocks being coated with GLS Coatings' Polyurea. The coating is spray-applied and is touch-dry in UNDER 10 SECONDS. The coating is then immediately subjected to blows from a sledgehammer. The coating is fully intact - but the breeze-blocks not coated are completely destroyed by the impact.”

Options for ERCs are widespread now, all generally made from the same polyurea, polyurethane, or combined with other blast mitigation techniques. It’s advertised that a wall coated in an ERC (such as PAXCON, ArmorBlast, Defend-X, and many other blast mitigation coatings) can withstand explosion forces up to 20 times an equivalent, non-coated wall. It can be used with wood, concrete, brick, steel, and other structural engineering materials in both commercial and military applications.

A much more incredible demonstration of and ERC coated cinder block wall and a control wall hit by a simulated average car bomb explosion. The inside view at 1:10 shows the wall bulge inward, but contained by the ERC coating.

Caption from YouTube Video - “Watch how a composite application of polyurea and Kevlar sheet prevent this cinder block wall from explosion. The blast was big enough to simulate an average car bomb. The left side of the wall was left as built for the control wall. The right side coated with polyurea”

The ONR, after 9/11, expanded its research to include protection against “ballistic penetration, land mines, and improvised explosive device” (IED) blasts. The polymer was applied to multipurpose and troop transport vehicles. From here, spray-on iterations of the ERC polymer were developed and more widely deployed.

Here’s a bonus more fun video and very informative chemical explanation of the ERC made by Line-X. The chemical reaction is demonstrated and a watermelon coated in PAXCON and thrown from a tower, accelerating to over 66 MPH!

Caption from YouTube Video - “Used in everything from bullet-proof vests to the walls of the Pentagon, polyurea's strength comes from its long-chain molecules.”

Jarrett Linowes
Mechanical Engineer

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