Effects of Expansive Agents on Deformation Property of CA Mortar

In order to maintain the volume stability of CA(cement asphalt) mortar,the effects of the type and dosage of expansive agents and curing humidity on the volume stability of CA mortar were investigated experimentally.The investigation results indicat that the expansion effect of aluminum powder occurs within 12 h after casting,and volume shrinkage occurs after 16 h.U-type expansive agent has a little shrinkage compensating effect within 12 h,but the volume of CA mortar expands obviously after 20 h and reaches the maximum at 7 d after casting,and volume shrinkage is followed immediately.Furthermore,the shrinkage ratio reduces with increasing the dosage of U-type expansive agent.The volume of CA mortar including aluminum powder and U-type expansive agent expands persistently within 7 d,and volume shrinkage follows and decreases with the increase of curing humidity,from 0.035‰ to 0.100‰.M-type expansive agent can reduce remarkably volume shrinkage at the later stage,and the shrinkage ratio decreases by more than 0.160‰ at 180 d after casting.