Thursday, May 8, 2014

Frangible Bollards for Structural Concrete

Protecting assets and pedestrians in a concrete structure often poses particular challenge to designers and architects.  Any bollard used must be strong enough and imposing enough to prevent errant vehicle traffic from causing damage, but yet cannot be a liability to the entire structure.  For this reason, embedded bollards are rarely used in pre- and post-tension concrete structures.  Should a vehicle impact and embedded bollard that does not give, potential for catastrophic structural failure exists.  Further, options to repair bent bollards are severely limited, leaving the property owner stuck with unsightly bollards.









This has left architects and property managers with only welded steel plate bollards as a safe option.  Even when used, often the anchor have to be design for shearing to avoid the possibility of damaging tendons. Unfortunately, as most parking garage owners know, welded-plate bollards are extremely weak and easily damaged, as this outdoor photo demonstrates.


Today there is a new type of bollard that offers the protection rivaling embedded bollard, while maintaining the integrity of the structural concrete.  The patented SlowStop Rebounding Bollard system is a surface mounted bollard that absorbs impacts using a unique energy absorbing disc hidden in the bottom of the bollard system.  This disc allows the bollard to tilt approximately 20 degrees upon impact, then rebound to upright (see DEMO VIDEO).  It is attached to concrete by way of concrete screw anchors, however the base of the bollard system, and the bollard pipe itself, are both designed to bend or break before the anchors pull out the foundation concrete.


Not only does this system provide for a superior safety in a structural concrete building, but it reduces damage to vehicles that may impact the bollard.  It also takes reduced damage itself, due to the shock absorbing properties of the rebounding bollard.  Should any part of the system become damaged, each part can be changed out in modular fashion.  The system is easy to install and usefully in retro-fit situations once tendon locations have been identified.

The system is available in 3", 4", and 6" sizes, each of which is specified based on quantifiable energy absorption testing data.  The 4" bollard is even particularly useful for creating bollard enhanced handicap parking sign posts.


Visit www.slowstop.com to learn more about this innovative new product and how it solves one of today's trickiest design problems for parking garages and structural concrete buildings.