ISSN: 0149-6123
CODEN: CCAGPD
Page Count: 5

Effect of Curing on Shrinkage and Expansion of Surface Repair Mortars
Durand, B
Researchers, Service Technologie des Matériaux, Direction Technologies de production et Matériaux, Vice-présidence, Technologie et IREQ, Hydro-Québec, Québec

Mirza, J
Researchers, Service Technologie des Matériaux, Direction Technologies de production et Matériaux, Vice-présidence, Technologie et IREQ, Hydro-Québec, Québec

Abstract

Hydro-Québec has undertaken a major study on the evaluation of repair materials for concrete surfaces damaged by erosion. Shrinkage-expansion and compressive tests, among others, were carried out on 36 different products: 12 cementitious mortars and grouts, eight cement-based mortars containing styrene-butadiene rubber (SBR), four cement-based mortars containing acrylics, and 12 epoxy mortars. For each mix, four 25 by 25 by 275-mm bars and six 51 by 51 by 51-mm cubes were prepared for shrinkage-expansion and compressive-strength tests, respectively. Specimens were demolded after 24 h and placed at 21°C and 100% relative humidity for another 24 h. After that, half the bars were put in lime-saturated water, the other half in air at 50% relative humidity (both cured at 21°C). With respect to the cubes, half were placed in air at 21°C and 50% relative humidity, the others in a moisture chamber. Among the 35 products tested, two cementitious grouts made with special cement and artificial aggregates showed the lowest shrinkage-expansion behavior and the highest compressive strength (over 80 MPa). Two polymer-modified cement-based mortars containing SBR had shown large water expansion and air shrinkage, whereas another cement-based mortar containing SBR showed little shrinkage expansion and high compressive strength. Four of the 12 high sand: epoxy ratio mixes exhibited very large water expansion, whereas most products showed little air shrinkage.

Keywords:
acrylics, concrete, epoxy, expansion, grout, mortar, shrinkage, styrene-butadiene rubber

Paper ID: CCA10561J
DOI: 10.1520/CCA10561J
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