Title:
ACI CRC 18.517: Guideline Development for Use of Recycled Concrete Aggregates in New Concrete
Author(s):
Matthew P. Adams
Publication:
CRC
Volume:
Issue:
Appears on pages(s):
89
Keywords:
DOI:
Date:
11/4/2019
Abstract:
modulus have shown excellent agreements in comparison with the existing database analysis prepared for compressive strength and elastic modulus. Future iterations of these statistical analyses can be made with an expanded database as more information is available through continued research. The database has been made available online, and the authors hope to continue to update it over the coming years. Overall, the RCA replacement ratio and the water-to-cement ratio had higher variabilities, while other factors such as mix proportioning parameters and aggregate properties had minor effects on the mechanical properties of RAC systems over the large dataset. Minimal strength loss was observed when RCA replacement levels increase above 20%. Results specifically focused on compressive strength, elastic modulus, flexural strength, and splitting tensile strength are presented. Aggregate-to-cement ratio and RCA replacement level were found to be the most significant factors that can cause major impact on RCA compressive strength at 95% confidence interval. Further, effective water-to-cement ratio was not significant at the 95% confidence level, yet, it showed a substantial main effect on the compressive strength response of RAC systems. Durability properties of RCA have also been studied in this report. However, a major statistical analysis was not able to be completed due to the large variation of those testing methodologies used to quantify the durability properties. A substantial section of the report has been dedicated in the literature review on specific durability properties addressed in published journal articles. Durability properties on RCA such as shrinkage, creep, abrasion resistance, permeability, and freeze-thaw resistance were studied in this report and detailed in the literature review section.