The Research on Early Age Deformation of Shrinkage-Compensating Concrete

Measuring techniques for vertical deformation and horizontal deformation of concrete were introduced in the paper. Based on these techniques, concrete deformation about reference concrete and shrinkage-compensating concrete were studied. The results show that workability of concrete was almost not affected by expansive agent. Usually deformation testing began when the mold has been removed 24 hours after casting according to present standard, but the reaserch shows that the time of starting measurement has a little influence on deformation of reference concrete, while it's vastly affected on those of shrinkage-compensating concrete with expansive agent. Thus, it's essential to judge time-zero accurately for shrinkage-compensating concrete. Before final set, concrete is on the plastic stage when the concrete has no enough stiffness to store expansive energy, so the measurement results should be zeroed to the time of final set especially for concrete with expansive to evaluate expansive validity better.