TY - JOUR

T1 - The role of residual cracks on alkali silica reactivity of recycled glass aggregates

AU - Maraghechi,Hamed

AU - Shafaatian,Seyed-Mohammad-Hadi

AU - Fischer,Gregor

AU - Rajabipour,Farshad

PY - 2012

Y1 - 2012

N2 - Despite its environmental and economical advantages, crushed recycled glass has limited application as concrete aggregates due to its deleterious alkali-silica reaction. To offer feasible mitigation strategies, the mechanism of ASR should be well understood. Recent research showed that unlike some natural aggregates, soda-lime glass undergoes ASR within cracks in the interior of glass particles and not at glass–paste interface. These cracks originate during bottle crushing and propagate further by ASR. This paper examines whether glass aggregates could become innocuous if these cracks are healed by annealing or when the crack widths are smaller than a critical size. The results confirm that glass annealed at 650°C for 40min or particles containing cracks smaller than approximately 2.5μm can be considered innocuous based on ASTM C1260. Also larger glass particles contain significantly higher percentages of reactive microcracks which may explain why ASR expansions are lowered by reducing the size of glass aggregates.

AB - Despite its environmental and economical advantages, crushed recycled glass has limited application as concrete aggregates due to its deleterious alkali-silica reaction. To offer feasible mitigation strategies, the mechanism of ASR should be well understood. Recent research showed that unlike some natural aggregates, soda-lime glass undergoes ASR within cracks in the interior of glass particles and not at glass–paste interface. These cracks originate during bottle crushing and propagate further by ASR. This paper examines whether glass aggregates could become innocuous if these cracks are healed by annealing or when the crack widths are smaller than a critical size. The results confirm that glass annealed at 650°C for 40min or particles containing cracks smaller than approximately 2.5μm can be considered innocuous based on ASTM C1260. Also larger glass particles contain significantly higher percentages of reactive microcracks which may explain why ASR expansions are lowered by reducing the size of glass aggregates.

KW - Annealing

KW - Recycled glass

KW - Crack

KW - Alkali-silica reaction

KW - Scanning electron microscope

U2 - 10.1016/j.cemconcomp.2011.07.004

DO - 10.1016/j.cemconcomp.2011.07.004

M3 - Journal article

VL - 34

SP - 41

EP - 47

JO - Cement and Concrete Composites

T2 - Cement and Concrete Composites

JF - Cement and Concrete Composites

SN - 0958-9465

IS - 1

ER -