Environmental Effects on Durability of Aggregates Stabilized with Cementitious Materials

Abstract

The present study focuses on investigating the effect of freeze–thaw (FT) cycles, referred to as environmental effect in this paper, on aggregates stabilized with various stabilizing agents, namely, cement kiln dust (CKD), Class C fly ash (CFA), and fluidized bed ash (FBA). Cylindrical specimens were compacted and cured for 28days in a moist room with a constant temperature and controlled humidity. After curing, specimens were subjected to 0, 8, 16, and 30 FT cycles, and then tested for resilient modulus (Mr). Results showed that Mr values of stabilized specimens decreased with increasing FT cycles up to 30. The reasons for such changes are explained by the increase in moisture content during thawing and the formation of ice lenses within the pores during freezing, causing distortion of the matrix of particles. It was also found that the decrease in Mr values varied with the type of stabilizing agents. The CKD-stabilized Meridian and Richard Spur aggregates exhibited a higher reduction in Mr values than the corresponding values of CFA- and FBA-stabilized specimens. The CFA-stabilized Sawyer specimens performed better than their CKD- and FBA-stabilized counterparts.