Development of High-Performance Concrete Mixtures for Durable Bridge Decks in Montana Using Locally Available Materials

Abstract

The Montana Department of Transportation (MDT) is performing research to develop a cost-effective, indigenous high-performance concrete (HGC) for use in bridge applications. The investigation was divided into two tasks: (1) identification of the optimum cementitious matrix for the HPC and (2) evaluation of the performance of this matrix in combination with aggregates readily available in Montana. The work focused on the use of binary, ternary, and quaternary blends of portland cement with fly ash (Class C and F), slag, calcined clay, metakaolin, and silica fume, in combination with Yellowstone River and Western Montana aggregate sources. Testing included plastic properties, setting characteristics, air-void system parameters, electrical conductivity, strength, chloride diffusion, freezing and thawing resistance, scaling resistance, and drying shrinkage. The paper discusses the process required to test and implement HPC specifically for bridge deck applications and presents the test results for this MDT study. The supplementary cementitious material combinations that produced the best performance were silica fume alone, silica fume and slag, Class F fly ash, silica fume and slag-blended cement, and silica fume and calcined clay-blended cement. The importance of raw material testing and the practical reproducibility of the concrete mixtures are also considered.