Question: A shopping center has accepted our bid to precast a 5 ½-foot cube with truncated corners. The specifications are so vague that we are not sure how to go about it. The specifications permit the cube to be hollow but they say "reinforce as necessary." How do we know what is necessary?

We want to construct this in a way that will not result in cracking.

Answer: Although it might be possible to produce this job with steel-fiber or glass-fiber concrete it might be better to construct it of ferrocement.

The job does not seem too different from construction of boat hulls and houses with ferrocement. Ferrocement construction methods have been described in detail in a number of articles in Concrete Construction magazine as listed in the cumulative index found in the annual Reference Guide, which is the December issue of each year. It may be difficult but certainly not impossible to produce sharp edges and corners.