Recycled aggregates derived from excavation materials—mechanical performance and identification of weak minerals

Abstract

The present study investigates the mechanical performance of recycled aggregates derived from excavation materials (REM). REM is blended with different quantities of recycled phyllite materials (RPM) and is investigated by Los Angeles (LA) and micro-Deval (MD) tests. X-ray diffraction (XRD) and acid solubility test are performed on the pulverized fractions < 1.6 mm obtained from the LA and MD tests to assess the respective degree of fragmentation and wear of mineral components. The results of the materials in unblended conditions showed considerable difference between MD performance while similar performance was found for LA. Furthermore, about 40% of RPM was sufficient to blend with REM without disturbing the required performance for blended mixtures. Mechanically weak minerals, i.e., phyllosilicates in RPM, significantly influenced the MD performance in blended and unblended varieties, and limestone minerals seem to disintegrate when mixed with amphibolite -which has the potential to dissolve in acidic environments.

Technical and Environmental Properties of Recycled Aggregates Produced from Concrete Sludge and Excavation Materials

“…For RCZ0, the WA obtained is higher than 0.3% reported for similar material in the study [30]. Studies that have investigated the performance of RCSA reported WA values within the margin 4-13% [20,22].…”

“…Regarding the LA for RCZ0, other studies have reported stabilized results for excavation materials within the range of 24-28% [30,31]. The LA for RCZ50 also show the optimal intermix of recycled aggregates RCZ and excavation materials.…”

Repeated Load Triaxial Testing of Recycled Excavation Materials Blended with Recycled Phyllite Materials

“…The LA determines the resistance to fragmentation, whereas MD evaluates wear resistance. The LA values for REM and RPM were 28% and 26%, respectively, whereas the MD was reported to be 6% and 26% [14]. The MD results varied significantly between REM and RPM.…”

“…The complete test setup with the chamber filled with water is shown in Figure 3h, and Figure 3i shows the computer for data collection. tively, whereas the MD was reported to be 6% and 26% [14]. The MD results varied significantly between REM and RPM.…”

“…In particular, good Los Angeles (LA) and micro-Deval (MD) performance are reported [9]. A comprehensive study of mixing different levels of recycled phyllite materials (RPM) with REM to assess the mechanical properties (LA and MD) and identify mechanically weak minerals was performed [14]. The results showed that intermixing RPM significantly affected the MD at high mixing levels (>40%).…”