Title:
Aggregate and Petrographic Laboratory (APL) Research Program
Author(s):
Mengesha Beyene
Publication:
Web Session
Volume:
Issue:
Appears on pages(s):
Keywords:
DOI:
Date:
10/25/2020
Abstract:
Petrographic methods using quantitative image analyses for evaluating the quality of RCA from four different sources. A combination of semi-quantitative tabulated data transmitted light thin section petrography, fluorescent light thin section microscopy, and quantitative image analyses are utilized to rank RCAs in accordance with their overall qualities. The properties considered for prioritization are thickness of residual mortar (mortar cover); relative hardness and water absorption rate of the residual mortar; area fraction ratios of denser to less dense and porous paste; quality of the interfacial transition zone (ITZ); the relative collective condition of RCA. Petrographic evaluation can provide information on cracks/damage related to alkali aggregate reactivity (AAR), sulfate attack, freeze-thaw, delayed ettringite formation (DEF) and other concrete transportation-related durability issues. Petrographic evaluation of RCAs may be a helpful to prioritize different sources and help to select the appropriate applications of RCA in highway and other transportation of aggregates.