Dr. Melito A. Baccay presenting the results of his research.
The National Research Council of the Philippines (NRCP) proposes formulating policy recommendations based on its awardee’s outstanding research in construction engineering that may help improve the present standards set by the government for housing and building construction. NRCP is the country’s principal advisory agency in science and technology.
Dr. Melito A. Baccay presented his study results during the Scientific Session of the NRCP Division of Engineering and Industrial Research last July 7 in España, Manila, and pointed to the country’s high level of humidity and temperature and poor construction practices that resulted in debilitated houses and buildings in the country. He was conferred the 2015 NRCP Achievement Award for his pioneering works and innovations on durability studies in concretes.
According to Dr. Baccay, corrosion of concrete is a very serious problem in the construction industry and in the Philippines. He explained that corroded concrete causes the steel bars to deteriorate thus shortening the service life of a structure. The country’s high humidity and temperature are also critical factors because these speed up corrosion rate, his study also found.
Dr. Baccay observed that the rate of corrosion is faster and higher in structures exposed to marine environment because of high amount of chloride seeping through the concrete. When chloride is high (which means that the pH drops considerably), the concrete will hold more moisture which will eventually attack the integrity of steels when rusting takes place. He said that at a pH of 11.5, the concrete is considered stable.
Poor construction practices are also a long standing and a very rampant problem in the construction industry. Dr. Baccay randomly inspected some buildings in one locale and observed structural defects attributed to poor construction practices. He said that workers tend to add too much water to the cement which causes the water to separate from fresh cement and to rise eventually on the surface (called bleeding in construction engineering). Too much water on the surface renders the concrete to be porous which can invite easy penetration of carbon dioxide. This process is called carbonation which weakens the integrity of the structure.
Aside from corrosion mechanism, Dr. Baccay presented ways to control corrosion such as use waterproof membranes; an overlay of watertight concrete of 37.5 to 63 mm thick, and protective coatings to reinforce steel bars.
Dr. Baccay said that the findings of the study would be very useful if they will be integrated in the standards used by government licensing office for contractors and builders both from the private and the public sectors.
NRCP Executive Director Marieta Bañez Sumagaysay said that NRCP should be proactive to this cause and come up with policy recommendations that could be used by concerned agencies such as the Department of Public Works and Highways and policy making bodies involved in construction engineering.