At head of title: National Cooperative Highway Research Program.

This study is an investigation of the cause(s) of premature failure of latex modified concrete (LMC) bridge deck overlays in Ohio. Data and materials for 93 bridge decks overlaid with LMC were collected from five Ohio Department of Transportation Districts. Additional materials were collected and evaluations were conducted through monitoring the construction of seven LMC bridge deck overlays. Overall documentation and evaluation of the overlays and materials obtained are discussed; this includes field survey activities, construction monitoring and laboratory testing and analysis. Characteristics of the LMC mixtures and materials are evaluated and compared to acceptable standards. General findings were that most of the problems were due to the underlying old deck which was contaminated with chloride ions, previously undetected due to insufficient testing. Other conclusions are presented separately under construction monitoring, field surveys, and laboratory testing and analysis.

This synthesis wil be of interest to materials engineers, construction engineers, maintenance engineers, pavement contractors and others interested in the use of latex-modified mortars (LMM) and concretes ( LMC). Information is provided on material properties of various LMM and LMC, as well as current construction practices used for LMM and LMC. Potential applications for LMM and LMC are also included. The use of innovative modified portland cement mortars and concretes for construction and maintenance applications is growing. This report of the Transportation Research Board describes the current state of the practice with respect to the use of latex-modified portland cement concretes and mortars. The extent of use of each material (including case histories), based on results of surveys of state highway agencies and a review of the literature, is summarized.