Effect of prewetting methods on some fresh and hardened properties of concrete with pumice aggregate

One of the major problems in lightweight aggregate concrete production is the high water absorption characteristic of the aggregates due to their porous structure. This problem is usually overcome by prewetting the lightweight aggregates or increasing the amount of mixing water. Since aggregate prewetting methods significantly affect fresh and hardened lightweight concrete properties, it is important to take this into account before the concrete production process.This study is focused on the effects of three prewetting methods on some fresh and hardened properties of pumice lightweight concrete. Pre-soaking, water-soaking and vacuum-soaking methods were applied to pumice lightweight aggregate prior to mixing. Test results showed that fresh and hardened properties of concretes with vacuum-soaked and water-soaked lightweight aggregate were significantly better than that of concretes with pre-soaked lightweight aggregate. Vacuum-soaking and water-soaking of pumice aggregate improved workability, compressive strength and drying shrinkage of pumice lightweight concrete.