Integration of reclaimed asphalt aggregates into glass fiber-reinforced alkali-activated composites: Mechanical performance and durability

This study investigated the mechanical, durability, and microstructural properties of alkali-activated composites (AAC) reinforced with glass fibers (GF) and incorporating reclaimed asphalt pavement aggregate (RAP) as a substitute for river sand (RS). Ground blast furnace slag (GBFS) served as the primary binder, with RAP replacing RS at 25 %, 50 %, and 100 % by volume. GF were added at varying levels of 0 %, 0.5 %, and 1 %. The composites were tested under both ambient conditions and elevated curing temperatures (80 degrees C) for 24 h., evaluating their compressive and flexural strengths, high-temperature resistance, freeze-thaw durability, sorptivity, transport properties, and microstructural characteristics. The results indicated that replacing RS with 25 % RAP resulted in the highest compressive strength. A substitution of RS with 50 % RAP also led to an increase in compressive strength compared to the reference mixture. However, when RS was replaced with 100 % RAP, a slight reduction in compressive strength was observed, independent of curing conditions or the addition of GF. The mixture containing 25 % RAP and 0 % GF demonstrated the highest compressive strength, whereas the mixture with 100 % RAP and 1 % GF showed the lowest compressive strength under both ambient and 80 degrees C heat curing conditions. GF significantly enhanced the flexural strength of the AAC mixtures, with the mixture containing 1 % GF and 25 % RAP achieving the maximum strength by a 24.27 % increase in flexural strength compared to the reference mix. At 600 degrees C, ambient-cured mixtures experienced significant strength loss (84 %-89 %), while 80 degrees Ccured mixtures showed a strength loss of 81 %-85 %, regardless of RAP or GF content. All ambient-cured mixtures showed strength loss between 8.98 % and 56.46 % after 60 F-T cycles, with the least loss in the mixture with 25 % RAP and 0.5 % GF, and the most in the one with 100 % RAP and 1 % GF. For 80 degrees C-cured mixtures, strength loss ranged from 24.49 % to 45.89 %, with the least loss in the mixture with 50 % RAP and 0 % GF, and the most in the one with 100 % RAP and 0.5 % GF after 60 F-T cycles. This study highlights the potential of using RAP in alkali-activated composites to develop environmentally friendly construction materials.

Dergi

CONSTRUCTION AND BUILDING MATERIALS

Yıl

2025

Cilt

458

ISSN

0950-0618

eISSN

1879-0526

DOI

10.1016/j.conbuildmat.2024.139645

WoS UID

WOS:001394269300001