Contribution of the Blast Furnace Slag on the Behavior of HPC in a Hydrochloric Environment

Abstract

Most mechanical properties and durability of cementitious materials are related to the performance of the hydrated cement that coats the granular skeleton. However, different mineral additions are currently used in concrete. They are used as addition or substitution to cement. The use of these supplementary cementitious materials provides to concrete a denser matrix that will be more resistant to aggressive environments such as sulphates, chlorides and other aggressive agents. In mixtures containing finely ground of slag, 15% of cement by weight was replaced with finely ground of slag of El-Hadjar (Algeria). The main objective of this study is to investigate the effect of curing in the hydrochloric environment by subjugating its granular effect on the performance of concrete. Density, compressive strength, concrete surface, internal microstructure and ultrasonic pulse velocity were investigated in this research. The damage mechanisms of concrete have been related to the development of the microstructure of the material. The degradations were observed using a scanning electron microscope (SEM) and quantified by x-ray diffraction (XRD). The microstructural study concerns both the surface layer and the internal structure of the samples. The results have shown that slag of El-Hadjar present a pozzolanic activity and hence it affects favorably the microstructure of the paste which becomes denser and less permeable.

Keywords

• microstructure
• slag
• durability
• hydrochloric