SHRINKAGE BEHAVIOR OF AN ECO-FRIENDLY ENGINEERED CEMENTITIOUS COMPOSITE

Abstract

The purpose of the present research is to assess the impact of foundry sand (FS) and cement kiln dust (CKD) on the autogenous shrinkage, drying and total shrinkage of engineered cementitious composites (ECCs) over 100 d. Additionally, the pore sizes and their distribution in the developed ECC system were assessed through the BJH adsorption technique. The findings showed that the pore structure was refined continuously over time. This indicates that the CKD-modified ECC mixes demonstrated decreased autogenous shrinkage at the early and later ages of the 100-d period, although the total shrinkage, developed during the later stages, was comparable to the CKD/FS mixes and conventional ECCs. Specimens with 30 % FS and 15 % CKD inclusions showed significantly fewer medium capillary holes and more gel pores. As the pores in a CKD-modified ECC system are smaller than in the traditional ECC, the modified ECC specimens are denser and show a lower loss of water.