Abstract: An apparatus for producing lightweight aggregate concrete utilizing fully saturated aggregate particles includes a vacuum vessel that discharges substantially directly into a concrete mixer that combines the aggregates with quantities of cement and water to create a batch of lightweight aggregate concrete. The vacuum vessel receives a supply of non-saturated lightweight aggregates from a bulk supply bin. A pump evacuates the air from the vessel until a desired vacuum level is attained, which evacuates air from the pores and interstitial spaces within the aggregate particles. The volume of water needed to fully saturate the aggregates within the vessel is fed into the vessel to create fully saturated aggregates that are subsequently discharged into the concrete mixer. The second volume of water needed to hydrate the cement is added to the vessel to flush out the vessel and be discharged into the concrete mixer to produce the batch of concrete.