The Need for More Reliable Concrete Masonry
In the wake of the severely damaging tornadoes in the South and Midwest, concerns are being raised on the dependability of concrete structures. Undeniably, there is a need for better protection from the rage of storms and serious weather disturbances. Modular and typical buildings are just not going to cut it. If concrete masonry is used, it should one that is reliable and resilient enough to weather gales and violent winds that can uproot decades-old trees.
These days, safe rooms or shelters should be considered essential parts of houses or buildings. However, these rooms should not be built following ordinary standards of structural integrity. They have to be designed according to more rigorous guidelines like the ones set by the Federal Emergency Management Agency and ICC. Strong winds generated by tornadoes are unlike the regular strong gusts of wind that can be expected in certain parts of the year. It is necessary to apply standards that can ensure safety.
Advocating for More Resilient Construction
NCMA or the National Concrete Masonry Association is one organization that advocates for the implementation of codes and policies that ensure more reliable construction. In view of the devastation left by the recent tornadoes, the NCMA recommends the use of reinforced concrete masonry. This material is said to be capable of prevailing against strong winds and, more importantly, wind-born debris. The debris hurled by devastating winds pose the most serious threats to life and property. It is but logical to ensure that the materials used are capable of withstanding the heavy blows from randomly striking debris.
An investigation performed by the Wind Science and Engineering Research Center of Texas Tech University for NCMA found that the concrete masonry units promoted by NCMA are capable of withstanding the winds and projectiles being thrown by tornadoes. The concrete masonry units tested were 6” and 8” panels reinforced with 3000 PSI concrete and No. 4 and No. 5 rebar in every block cell. The tests and simulations used were based on the possible damages that can be caused by a 250 mph F-5 tornado.
Standard for the Design and Construction of Storm Shelters
Storm shelters are expected to be designed and built following the standards established in the ICC/NSSA Standard for the Design and Construction of Storm Shelters. The standard specifies requirements for creating a main wind resisting structural system, components, and the methods for cladding shelters to ensure the safety and health of shelter occupants. These requirements also cover the need for appropriate lighting, ventilation, egress, fire exit, and recommended space allotment for every occupant.
After the NCMA-commissioned test, it can be said that the guidelines set by Federal Emergency Management Agency (FEMA) are more than adequate in providing protection against powerful storms and tornadoes. The guidelines may even be revised to lower certain reinforcement requirements. The calamity that happened recently apparently demonstrates not the lack of guidelines but the lack of preparedness and implementation. Precautions that should handle the threats of unexpected devastating weather disturbances should not be disregarded.