Bulk engineering and durability properties of washed glass sand concrete

The paper reports the results of an experimental programme aimed at examining the performance of Portland-cement concrete produced with washed glass sand (WGS), as natural sand substitute- by mass. The effects of up to 50% WGS on fresh, engineering and durability related properties have been established and its suitability for use in a range of normal-grade concrete production assessed. WGS characteristics results showed that the post-container glass waste can be crushed to provide WGS of physical properties that satisfy the current requirements set in appropriate standards for natural sand for concrete. The density and water absorption of WGS was found to be lower than natural sand. The results for fresh concrete showed a reduction in workability of concrete with increase WGS proportion beyond 20% in the mix, although slump measurements remained within the allowable margin of ±25 mm. The mixes with high proportions of WGS were found to be less cohesive. Studies of hardened concrete properties, comprising bulk engineering properties (compressive cube and cylinder strength, flexural strength, modulus of elasticity, drying shrinkage) and durability (near surface absorption, alkali silica reaction) showed similar performance for concrete produced with natural aggregates and up to 15% WGS.