A critical assessment of concrete and masonry structures for reconstruction after seismic events in developing countries

Haiti is not alone amongst developing nations that have suffered losses due to the poor construction of concrete and masonry structures in an earthquake. In the wake of the disaster, a considerable amount of public sympathy and substantial funding was raised that supported short term, front line activities. However, there is little recognition of the need for adequately funded systems of organization and long-term support, particularly with respect to the design, structure and reconstruction of buildings. Much of the research and proposals made for the better rebuilding of Haiti, primarily focuses on the creation, education, and enforcement of “better” construction methods, life safety standards and codes imported from developed countries. These fail to address the other, perhaps more important, social and economic issues that led to substandard structures in the first place. Masonry and concrete buildings are typical throughout Haiti, and are continuing to be proposed for reconstruction. Research has shown that the structures of these concrete buildings are both unreliable and ineffective when natural disasters occur, due to compromised construction in the quality or quantity of materials. It is noted that the Haitian construction of recent buildings and particularly those that have collapsed in the 2010 earthquake were all built with poor concrete mixes. When mixing the concrete, builders would use the poorest quality of sand for concrete and save the more valuable sand for the exterior stucco of buildings. This also holds true for the amount of rebar used in the concrete as well. This paper concludes that continuing to rebuild with structural systems that can be easily compromised during construction due to economic hardship or societal inaction is not sustainable. The authors propose the use of structural systems that cannot be easily compromised, can be visually inspected after construction for code compliance, and analyze the barriers to their use in developing countries. Engineers, architects, scientists and others have already recognized that the process of construction is dysfunctional with no building codes in place and economic incentives to cut corners. Although the awareness of poor techniques have been made, engineers and architects are still proposing systems that are destined to be hazards once the next disaster occurs due to their continued use of masonry and concrete. Not only is the use of concrete economically and environmentally unsustainable but it is also the most vulnerable material when seismic activity hits the surface (Bilham 2010). Virtually all the buildings destroyed in the 2010 earthquake were poorly constructed, non-engineered, masonry and concrete buildings. Along side the poorly considered mixtures and the lack for reinforcement, the overall weight of the large mass of these buildings caused the majority of injury and death (Farmer 2011).