Optimization of Amount and Blending of Cementitious Materials in High-Performance Concrete

Abstract

In recent years, there has been a demand by the traveling public for longer-lasting, more durable transportation structures. One of the biggest problems encountered is the corrosion of reinforcing steel used in concrete applications. To reduce the damage caused by the ingress of chlorides, and the subsequent corrosion, the New York State Department of Transportation (NYSDOT) has developed and used a high-performance concrete, designated Class HP. As part of a continuous improvement effort to produce longer-lasting structures, research has been ongoing to further improve the characteristics of Class HP concrete. The study is a continuation of the previous experimental work performed by the NYSDOT and reported in Transportation Research Record 1574. During that study, the effects of microsilica, fly ash, and the total cementitious mass in a mixture on cracking and permeability of the resulting concrete were studied. The experimental design used in the investigation resulted in testing a minimal number of concrete mixtures yet allowed the analysis of a broad range of possible combinations. Statistical analysis of experimental data is presented, and examples of a scientific approach to experimentation are shown. The Response Surface Methodology was used with the appropriate statistical experimental designs, including the Box–Behnken design. In addition to the traditional linear regression models, a modern technique of the local regression was used.