If the thickness of the slab is changing dramatically, it is going to be hard to get the control joints to agree with where it actually cracks. I assume that this is in a building and it will not experience a lot of freezing conditions during the service life. I also assume that this is not a...
How did they solve the problem of the fibers balling up or being poorly distributed during the mixng process. Fibers in concrete is an old idea. Did the elimination of the large aggregate also eliminate the problems with low aggregate compressive srength? Gee, I guess this means they don't have...
45 feet is a long way for concrete to go without a joint. It sounds like it made itself a joint. Cracking can get exaggerated when water is added to the concrete just before it is poured. Even a cocrete block wall could not take such long distances without a joint. I wonder if the crack in the...
Try to pour it when it is cool or hose it down first. If the asphalt is hot from being open to the sun, the concrete could take the first set quicker than on soil. I doubt anyone will notice. If the surface of the asphalt is very rough, higher than usual shrinkage stress might be experienced...
There is usually enough safety factor to take care of some contractor related problems. It would bother me if the contractor, fearing that the concrete was about to take an initial set, added water to the mix to make the last of the pour go better. It might have been that adding water before the...
The standard rebar cage is usually 6 inches less in every direction than the nominal dimensions of the foundation. This looks a lot like a Faraday Cage. Could this steel tend to exclude lightning from the core of the foundation? Can lightning even penetrate to the steel since this would violate...
The Electrical Engineers want to spend less on lightning protection by using the legs of self supporting towers, 40 to 80 feet high as the down conductors. This has been allowed by NFPA-780 for years. The National Electric Code has permitted the use of rebar as a grounding electrode for...
Camber in a roof can cost in other ways. It can divide the water in two and generate a need for more roof drains and plumbing labor. Raising one end of the beam to eliminate the ponding, at least twice the camber, creates a lot of extra detailing costs. Another way to neutralize the water...
