Durability of Latex Modified Concrete Mixed with a Shrinkage Reducing Agent for Bridge Deck Pavement

Latex modified concrete (LMC) is used for a bridge deck pavement method that was introduced in Korea in the 2000s, and it is currently the concrete pavement method being used for most highway bridges. It has been recommended that mixing with latex approximately 15% in terms of polymer-cement ratio (P/C ratio) by weight showed no occurrence of cracks with sufficient tensile strength and bond strength of LMC. However, many cracks occur in the actual field mostly due to drying shrinkage of concrete, requiring frequent repair. Therefore, this study examined the feasibility of applying a shrinkage reducing agent(SRA) that could reduce plastic shrinkage cracks at early age as well as drying shrinkage cracks of LMC. Based on the test results, it was confirmed that adding a shrinkage reducing agent could secure the durability without affecting the fresh and hardened properties of LMC. The compression strength test results presented a 1.7-5.7% improvement in strength to the SRA mixture compared to the plain mixture. Length change test results indicated that SRA mix conditions presented more outstanding performance compared to mix conditions with the expansive admixture. The amount of shrinkage reducing agent suitable for achieving performance requirements in length change, crack resistance, chloride ions penetration resistance and scaling resistance, was evaluated as 3% by weight ratio of binding material under the limited condition of the present study.