A lawsuit brought by a number of homeowners who purchased new homes in Pooler, Georgia and Savannah, Georgia, alleges that bad concrete used in the construction of their homes has caused problems. The concrete was poured and utilized in the foundations, slabs, footings, garages, driveways and patios, which are cracking and pitting, and giving off a very fine silicate dust.
One of the problems identified in the concrete mixture was an excessive percentage of fly ash, which is a material that is mixed with cement to form concrete. Fly ash is a bi-product of burning coal. Fly ash contains calcium, and its calcium content is an indicator of how well fly ash will perform when mixed into concrete. Fly ash with higher calcium content, produced from burning lignite or sub-bituminous coal, is generally known as Class C fly ash. However, excessive amounts of fly ash can cause the concrete to crumble and disintegrate. This, in turn, can lead to a very fine silicate-like dust that can spread and pose a potential threat to the homeowners’ respiratory health.
A properly proportioned fly ash concrete mix can improve workability and increase the cohesiveness of concrete. On the other hand, a badly proportioned concrete mix, such as one with too much fly ash or the wrong class fly ash, will not set and harden properly. This can result in premature breakdown of a home’s foundations, footings, garages, driveways and patios. The most troubling of these problems is when the home’s concrete foundation begins cracking and crumbling, because a foundation with a house built on top of it cannot be easily repaired or replaced.