Title:
Recycled Concrete Aggregate Composition Determined Using a Portable Handheld XRF Device
Author(s):
Tara Cavalline
Publication:
Web Session
Volume:
Issue:
Appears on pages(s):
Keywords:
DOI:
Date:
10/23/2022
Abstract:
Use of recycled concrete aggregates (RCA) in lieu of natural aggregates improves the sustainability of the built environment. Primary barriers to increased use of RCA include its variable composition, including the residual mortar content (RMC), chemical composition, and its potential to contain contaminants which can negatively affect the properties of concrete or present environmental concerns. A rapid, economical method for estimating the RMC and providing chemical characterization of RCA would provide confidence to users in its suitability for use in new concrete or in unbound base or fill materials. In this study, a method was developed using a portable handheld x-ray fluorescence (PHXRF) device, which can be used to estimate the RMC and chemical composition of RCA. Models were developed based on reference tests (RMC test based on thermal shock method and chemical composition from Whole-rock analysis) to correlate PHXRF results to measured values. The PHXRF shows strong potential for estimating the RMC and chemical composition of RCA. Paired with locally calibrated reference samples, the proposed test method could be used in laboratory or field applications to better characterize RCA and increase its use in bound and unbound applications. Fostering the use of this technology could promote the use of RCA in concrete construction.