Title: Influence of Moisture Curing on Durability of Fly Ash Concrete for Road Pavements

Author(s): M. Vieira, I. R. de Almeida, and A. F. Goncalves

Publication: Symposium Paper

Volume: 192

Issue:

Appears on pages(s): 91-102

Keywords: abrasion wear; capillary; compressive strength; concrete pavements; curing; durability; fly ash; permeability; porosity

DOI: 10.14359/5743

Date: 4/1/2000

Abstract:
In Portugal, fly ash is sometimes used as a cement replacement material in concrete for road pavements. The percentages of replacement generally range from about 30% in the top pavement layer up to 50% in the bottom layer. A study was carried out to evaluate to what extent the water curing practice could affect some of the properties of concrete with different amounts of cement replaced by fly ash. For this purpose, several properties generally related to the durability of concrete pavements were determined. Abrasion test, as well as determinations of compressive strength, capillary absorption, oxygen permeability and open porosity, were performed on concrete mixtures with different cement and fly ash contents, using limestone coarse aggregate and natural siliceous sand. This paper presents results on the influence of different water curing times on these properties. The results show that fly ash concretes can develop satisfactory resistance to abrasion, even with large amounts of cement replacement. Concretes with lower permeability and higher strength generally tended to exhibit better abrasion resistance. In general, concrete performance was improved with longer water curing times.