Source: CP Staff
The devastating earthquake in Haiti has been viewed from every possible vantage point from humanitarian to political. But Cornell University Professor of Structural Engineering Ken Hover, added at the last minute to the World of Concrete speaker program, told the story of Haiti in a context that emphasized that much of the world's population depends on concrete and masonry construction. Showing dozens of photos of his recent trip to the heart of the city of Port-au-Prince, Hover described his mission to inspect the damage done to the Cornell-sponsored Gheskio medical clinic campus buildings. Coincidentally, the grounds were also where the U.S. military set up a field hospital.
Hover explained that concrete and masonry are usually the building materials of choice in nations like Haiti because there simply is no wood, clay, fiberglass, or other raw material available without being imported at great expense. After examining the medical center and labeling certain structures as uninhabitable, he went on to inspect other buildings around the area for possible habitation. He made the observation that since the shockwave traveled north-south, most walls running parallel to it remained intact, while walls aligned east-west failed.
The professor went into detail about typical home and light-duty/light-commercial construction in Haiti, which involves support beam at the corners and masonry block used as walls. Typical home erection involves incremental building as money becomes available and small amounts of cement and block can be purchased. Often blocks are homemade from a single mold, and the maker typically will attempt to get 20 blocks from one bag of cement, resulting in variable strength grades. Homeowners, acting as their own builders, tend to use very little mortar between the blocks in an effort to preserve a single bag.
While emphasizing and documenting the critical need for quality design, materials and construction technique, Hover also saw several excellent examples of well-made commercial buildings that performed as they should. And while many of the more modern buildings stayed standing so people could be evacuated, structural damage would eventually require them to be torn down.