Title: Mitigating Autogenous Shrinkage by Internal Curing

Author(s): M. R. Geiker, D. P. Bentz, and O. M. Jensen

Publication: Symposium Paper

Volume: 218

Issue:

Appears on pages(s): 143-154

Keywords: autogenous deformation; autogenous RH-change; early age cracking; internal curing; lightweight fine aggregates; mortar

DOI: 10.14359/13060

Date: 2/1/2004

Abstract:
The use of internal curing is a highly effective means of mitigating autogenous shrinkage in cement mortars (w/cm=0.35, 8 % silica fume). Two different sources of internal water supply are compared: 1) replacement of a portion of the sand by partially saturated lightweight fine aggregate and 2) the addition of superabsorbent polymer particles (SAP). At equal water addition rates, the SAP system is seen to be more efficient in reducing autogenous shrinkage at later ages, most likely due to a more homogeneous distribution of the extra curing water within the three-dimensional mortar microstructure. A comparison of the water distribution in the different systems, based on computer modeling and direct observation of two-dimensional cross sections, is given.