Evaluation of ultralightweight foamed glass aggregates in precast concrete

Abstract

AbstractThis project investigates the use of foamed glass aggregates in lightweight precast concrete. Precast mixes are evaluated for compression and split‐tension strength, and durability is assessed through rapid chloride permeability, thermal conductivity, alkali silica reactivity, and freeze–thaw performance. Mixes containing a 100% or 50% replacement of gravel with foamed glass aggregates are evaluated. The 100% mixes have a 28‐day compression strength = 23.3–27.89 MPa which is acceptable per structural lightweight concrete standards (ASTM C330), but the split‐tension strength falls short of ASTM C330 requirements. The 50% mixes have acceptable strength but exceed the maximum density allowed for lightweight concrete in ASTM C330. The mixes exhibited low–moderate permeability but poor freeze–thaw resistance. All of the proposed mixes with one exception have acceptable expansion due to alkali silica reactivity. The thermal conductivity of the mixes varies from typical lightweight to normal weight concrete ranges with respect to the aggregate replacement ratio.