Dry shrinkage performance of cement-stabilized reclaimed lime-fly ash macadam: Fid-Bau Portal

Dry shrinkage performance of cement-stabilized reclaimed lime-fly ash macadam

Sun, Yu / Li, Lihan / Liao, Jian / Huang, Chongwei

Highlights • Optimum moisture content of CSR mixture is higher and maximum dry density is lower. • Dry shrinkage and its coefficient rise when substitution rate and cement content increase. • The dry shrinkage strain increases with the increasing of driage. • As the exposing time prolongs, dry shrinkage strain increases sharply.

Abstract An experimental study was conducted to investigate the compaction and dry shrinkage properties and the influencing factors of cement-stabilized reclaimed lime-fly ash macadam (CSR) compared with cement-stabilized macadam (CSM). The results indicate that the optimum moisture content of the CSR mixture is higher, whereas its maximum dry density is lower. The smaller the reclaimed particle size, the higher is the optimum moisture content and the lower is the maximum dry density. As cement content increases, the optimum moisture content and maximum dry density of the CSR mixture increase. For dry shrinkage properties, the driage, dry shrinkage strain, and dry shrinkage coefficient of the CSR mixture increase with increasing substitution rate and cement content, which are larger than those of the CSM mixture. After being exposed for 28 days, when the substitution rate of the reclaimed aggregates increases from 40% to 100%, the driage of the CSR mixture is 2.0–3.1 times, the dry shrinkage strain is 2.9–0.6 times, and the dry shrinkage coefficient is 1.6–1.8 times that of the CSM mixture. The dry shrinkage strain also increases with increasing driage. The strain is less in the early 7 days. As the exposure time increases, the dry shrinkage strain rapidly increases when driage reaches approximately 30% of the optimum moisture content.