Title: Durability of Concrete with Recycled Fine Aggregate

Author(s): T. Fumoto and M. Yamada

Publication: Symposium Paper

Volume: 234

Issue:

Appears on pages(s): 457-472

Keywords: carbonation; drying shrinkage; durability factor; pore volume; recycled fine aggregate; strength; water absorption

DOI: 10.14359/15952

Date: 3/22/2006

Abstract:
Recycling of demolished concrete is an effective method for reducing construction waste. Recycled fine aggregate includes a large quantity of hydrated cement paste. The cement paste influences qualities of recycled fine aggregate, and, in turn, the properties of concrete containing recycled fine aggregate. As a result, concrete containing recycled fine aggregate has lower strength and durability than concrete with natural aggregate. However, the manner in which the quality of recycled fine aggregate influences the properties of concrete remains unclear. When considering the use of recycled concrete for construction, the durability of concrete with recycled fine aggregate must be investigated. The purpose of this study is to determine the influence of the quality of recycled aggregate on the properties of concrete at W/C ranging from 0.25 to 0.7. The parameters investigated to evaluate durability are strength, pore volume, shrinkage, carbonation, and resistance to frost damage. The results show that water absorbed by the aggregate migrates to paste around particles of aggregate, and influences the volume of water and pores in paste. Therefore, when recycled fine aggregate with high water absorption is used in concrete, shrinkage and volume of gas permeating into concrete increase, and durability lowers.