Early age shrinkage and moisture loss of concrete
Title: Early age shrinkage and moisture loss of concrete
Author(s): N. Berke
Paper category : conference
Book title: International RILEM Symposium on Concrete Science and Engineering: A Tribute to Arnon Bentur
Editor(s): K. Kovler, J. Marchand, S. Mindess and J. Weiss
Publisher: RILEM Publications SARL
Publication year: 2004
Pages: 231 - 245
Total Pages: 15
Nb references: 16
Abstract: Major concerns with concrete slabs on grade are cracking, curling, and moisture loss if a topping is to be applied. This paper addresses work performed in Grace's Research and Development laboratory (Cambridge, MA) to address these issues.
Concrete slabs on grade often crack due to plastic and drying shrinkage. In addition, high performance concretes are susceptible to autogenous shrinkage that can result in early-age cracking even under water curing. In this paper the effects of shrinkage reducing admixtures (SRA's) and concrete mixture design on shrinkage are addressed. Testing included drying shrinkage of beams and larger members as assessed using embedded strain gauges. Curling was examined primarily using thin cement paste specimens sealed on all but one surface. Drying times of concrete slabs on grade affect the placement of floor coverings. The effects of reduced shrinkage and curling on drying time were examined. It is shown that the addition of a glycol-ether based SRA was very effective in lowering drying and autogenous shrinkage. It was found that the addition of a glycol-ether based SRA was the most effective means of obtaining a low moisture vapor emission rate (MVER) at a given RH. Thus, it is possible to dry a slab out faster with less shrinkage.
Online publication: 2004-02-04
Publication type : full_text
Public price (Euros): 0.00