The early evolution of the surface of hydrating portland cement The early evolution of the surface of hydrating portland cement Douglas Winslow School of Civil Engineering, Purdue University, West LaFayette, Indiana John Bukowski Center for Cement Composites, University of Illinois, Urbana, Illinois Portland cement concrete is the most consumed product on earth, with almost one ton of it being used for each human each year. Within the concrete, the component of greatest interest is the portland cement.
Cement is to the concrete as flour is to fruit cake.
The sand and aggregate that are present usually serve merely as cheap dilutents that limit shrinkage. Portland cement is a hydraulic cement that gains strength as it reacts with water. Once this reaction has begun, it is initially fairly rapid and slows with the passage of time. The hydration reaction products form as a finely divided, fairly porous solid between the aggregate particles. The specific surface area of any porous material is a critical descriptive parameter of its microstructure.