Concrete Deterioration, East Los Angeles County Area: Case Study

Abstract

Chemical deterioration of concrete foundations and floor slabs has affected residential structures in east Los Angeles County, California. Deterioration is recognized as mineral growths in and on cracked and uncracked concrete floor slabs. Field and laboratory studies indicate that the deterioration is due to water vapor transporting dissolved ions through foundation soils and overlying concrete floor slabs. Alkali mineral assemblages precipitate at the exposed concrete surface. Spalling and pitting of the concrete occurs due to high crystallization pressures. Vinyl floor tiles have peeled due to water vapor pressures and mineral crystallization. Remedial work has consisted of removing the affected slabs, and replacing them with new concrete slabs over a moisture barrier. An untried alternative to the removal and replacement repair is injection of a urethane foam beneath the affected slab. The slab would then be cleaned and cracks patched. A topical sealant would be placed over the slab.