Title:
Role of Chemical and Mineral Admixtures on the Physical Properties and Frost-Resistance of Recycled Aggre-gate Concrete
Author(s):
Rohi M. Salem and Edwin G. Burdette
Publication:
Materials Journal
Volume:
95
Issue:
5
Appears on pages(s):
558-563
Keywords:
air entrainment; compressive strength; fly ash; freeze thaw durability;
natural aggregate; recycled aggregate; recycled aggregate concrete;
DOI:
10.14359/398
Date:
9/1/1998
Abstract:
Recycling demolished concrete as an alternative source of coarse aggregates for the production of new concrete can help solve the growing waste disposal crisis and the problem of depleted natural aggregates. However, to make such recycling feasible, the strength and durability of the recycled aggregate concrete (RAC) must be assured. Even though much is known about the mechanical properties of recycled aggregate concrete, an important question remains about its freeze-thaw durability, and it appears that widespread utilization of such concrete will be limited until this question is addressed. This study was an attempt to investigate and compare how the frost resistance of the RAC and natural aggregate concrete (NAC) is affected by using mineral and chemical admixtures in their production. From the strength point of view, the recycled aggregate compared well with the natural aggregate in all cases and, therefore, could be considered for various potential applications. From the frost resistance point of view, the recycled aggregate had negative effects on durability performance. However, with the use of chemical admixtures, particularly air entrainment, the RAC was found to be as durable as the NAC.