Bridge & Highway Curing

What are the Big Boys using?

Weather conditions will most always determine what type of curing methods will be utilized in bridge & highway applications.  The most important conditions that are monitored by large commercial contractors is “Consistent Temperature & Moisture Levels.”  When 100′s of millions of dollars are on the table, nothing is left to chance… NOTHING.  The art of concrete curing has become a science, and the “BIG BOYS” know exactly what is required to achieve optimal PSI levels.  In a nut shell, what exactly is concrete curing?

The PCA explains it this way: “Curing is one of the most important steps in concrete construction, because proper curing greatly increases concrete strength and durability. Concrete hardens as a result of hydration: the chemical reaction between cement and water. However, hydration occurs only if water is available and if the concrete’s temperature stays within a suitable range. During the curing period-from five to seven days after placement for conventional concrete-the concrete surface needs to be kept moist to permit the hydration process. New concrete can be wet with soaking hoses, sprinklers or covered with curing blankets, or can be coated with commercially available curing compounds, which seal in moisture.

Leaving new concrete exposed to unpredictable weather conditions is never a good idea.  Fluctuating humidity, precipitation, temperature, and wind can be devistating to any bridge or highway construction project.  The difference between a bridge lasting 20 years vs 100 years will often be the result of proper curing proceedures.   I swallow hard everytime I drive over an old bridge, hoping our grandparents understood the science of curing.  Too many bridges are falling apart here in America when it might have been otherwise. 

The Science of Large Bridge Curing

With the advent of pre-cast concrete, many sections of a bridge can now be cured in controlled warehouses and pre-cast yards and then delivered to the construction site. This method of curing allows for tighter controls to be utilized and costly mistakes to be minimized.  Nothing is left to chance in large construction and similar methods can be used by smaller contractors and builders to assure desired results.

In 2006, a concrete bridge conference was held in Reno, NV which provided excellent guidelines on many basics that often get overlooked in the profession. Rapid bridge construction was highlighted and workshops were held to teach proper technique.  Please visit link for training resources. 

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