A reply to discussion by Z. P. Bazant of the paper “Drying shrinkage of portland cement pastes I. Microcracking during drying”

✍ Scribed by C.-L. Hwang; J.F. Young

• Publisher: Elsevier Science
• Year: 1985
• Tongue: English
• Weight: 116 KB
• Volume: 15
• Category: Article
• ISSN: 0008-8846
• DOI: 10.1016/0008-8846(85)90164-4

✦ Synopsis

Professor Bazant's concerns regarding the estimation of unrestrained drying shrinkage values for cement paste must be resolved if such values are to be used in the prediction of concrete shrinkage. We are in full agreement with regard to his statements about concrete. The presence of rigid, nonshrinking aggregate particles will restrain cement paste shrinkage in mortar and concrete, even if thin sections could be satisfactorily prepared.

However, the thick sections that must be used in practice lead to additional restraints due to hygral gradients, as pointed out by Professor Bazant, and we agree that the same will be true for paste specimens of thick cross-section.

The question is how thick is thick? Will I mm or 3 mm cross-sections produce a hygral gradient of sufficient magnitude and duration to affect shrinkage behavior?