More than 4300 students have chosen to advance their concrete knowledge through ACI.

When building a new headquarters for his concrete contracting company, the author decided to make the slab for the warehouse a working showplace. Using a concrete mixture that contained a high volume of large maximum size coarse aggregate to reduce shrinkage and macro polymeric synthetic fibers to help minimize plastic and drying shrinkage cracking, the joint spacing for the 6 in. (150 mm) thick slab was pushed to a 25 ft x 20 ft 10 in. (7.6 x 6.4 m) grid. Even after a year in service, the slab has an overall average FF 48/FL 38.

A new rheology-controlling admixture that offers the ability to overcome placement challenges associated with low-slump mixtures is described. The advantages include increased production rates, reduced vibration requirements for consolidation, and reduced equipment wear. It also improves placing and finishing and the performance of mixtures that include manufactured sand, while minimizing slump of unformed edges and enhancing surface appearance.