Durability of Lightweight Aggregate Pavement

Lightweight aggregate concrete (LWAC) is made using aggregates produced artificially, either from processed natural materials or processed industrial wastes. Considering that the choice of construction material is essentially determined by its technical suitability, durability, and ease of handling, the in-service performance of LWAC has been found to be highly satisfactory. An experimental section of a frontage road of an interstate highway was built in Houston, Texas, in 1963-1964 using lightweight aggregate, which was a locally manufactured expanded clay. After 34 years, the long-term performance of this concrete pavement section was evaluated in comparison to a normal concrete of the same age, from an adjoining location of the same pavement Different microanalytical techniques were used to study the microstructural characteristics of these concretes for a better understanding of the deterioration aspect. From visual inspection the normal concrete appeared to have developed additional cracks besides the preformed ones. Spalls were also observed in this concrete section. The LWAC is in relatively better condition.