Investigation of relationships between high strength self consolidating concrete compressive strength and macroscopic internal structure

Nine high strength self-consolidating concrete (HSSCC) mixes were prepared using high volume of cementitious materials utilizing up to 70% of slag, fly ash, and silica fume to replace cement content. The specimens were prepared using typical cylinders (100 × 200 mm) and were tested under pure compression. All specimens were cured under a constant temperature of 43.3 °C to simulate concrete structures produced in hot weather regions. 2-D digital images of HSSCC cylinders internal structure were obtained using a flatbed digital scanner and analyzed using iPas software. The digital image along with sample dimensions, aggregate gradation, air void content are the inputs for the software, the image analysis main output, among others, are number of contact points between aggregate, radial segregation of aggregate, and horizontal aggregate orientation. The results showed good correlations between HSSCC macroscopic structure and compressive strength, correspondence equations were introduced to predict the number of contact points and the horizontal orientation of aggregate in terms of the compressive strength.