A major consideration in designing and construction of bridge decks is the permeability of the concrete. Over the years, one of the ways permeability has been addressed is the development of latex-modified concrete. LMC contains a polymer that virtually seals the concrete. This not only keeps water from being absorbed into the concrete and expanding during freeze cycles but keeps any deicing agents used on the deck from penetrating into the steel below.
Almost all LMC is produced and placed using volumetric mixers. Volumetric mixers carry the cement, aggregates, water, latex modifier and admixtures called for in the specification and mix them on site.
GA & FC Wagman Inc. of York, Pa., has been a pioneer in the production of this material since the mid-1970s. They utilize Zimmerman Industries volumetric mixers on their projects. Harold Zimmerman, the founder of Zimmerman Industries Inc., Ephrata, Pa., is the original inventor of the equipment, and his patented delivery system enables the producer to meet all ASTM, AASHTO and ACI standards. Additionally, and equally as important, this patented design allows for quick and easy calibration and testing of the LMC as is typically required.