Laboratory evaluation of grid-reinforced HMA beams using the flexural bending-beam fatigue (FBBF) test in load-controlled mode. Issue 4 (21st March 2022)

• Record Type: Journal Article
• Authors: Walubita, Lubinda F.; Nyamuhokya, Tito P.; Torres P., Omar L.; Fuentes, Luis; Tanvir, Hossain A.; Souliman, Mena
• Is Part Of: International journal of pavement engineering. Volume 23:Issue 4(2022)
• Page Start: 1198
• Page End: 1212
• Publication Date: 2022-03-21
• Subjects: HMA -- reflective cracking -- grid interlayer reinforcement -- bending beam -- overlay thickness; Pavements -- Design and construction -- Periodicals; Highway engineering -- Periodicals; 625.805
• DOI: 10.1080/10298436.2020.1795659
• Languages: English
• ISSNs: 1029-8436

Abstract

ABSTRACT: Interlayer grid-reinforcement is one of the maintenance and rehabilitation (M&R) strategies often used to mitigate reflective cracking in hot-mix asphalt (HMA) overlays. However, there is no standardised laboratory test methodology for screening and selecting grid materials during the HMA overlay design stage. This laboratory study was conducted to comparatively evaluate, characterize, and quantify the crack resistance potential of grid-reinforced HMA using the flexural bending beam fatigue (FBBF) test based on the AASHTO T 321 concept. Two grid materials, denoted as FA-30 and FA-75, were comparatively evaluated against Control (unreinforced) HMA beam samples as the reference datum. The study findings indicated that the FBBF test setup, in a load-controlled mode based on the AASHTO T 321 concept, has promising potential as a test method for evaluating and screening grid materials in the laboratory. Overall, the grid-reinforcements used in the study exhibited over 4.0 times superiority in terms of laboratory flexural cracking-resistance performance improvement with the potential of over 25% reduction in the HMA layer thickness. The average laboratory interlayer crack performance benefit factor (ICPF), computed based on the indicative mirroring of the AASHTO R 50-09 concept, was 10.60 for FA-75 versus 5.14 for FA-30 with respective to laboratory performance.