Cement mortars and concretes

Title: Cement mortars and concretes
Author(s): C. Porteneuve, K.L. Scrivener, A. Jeknavorian, G. Gal, E. Gallucci, F. Serafin
Paper category : conference
Book title: International RILEM Symposium on Concrete Science and Engineering: A Tribute to Arnon Bentur
Editor(s): J. Weiss, K. Kovler, J. Marchand, and S. Mindess
Print-ISBN: None
e-ISBN: 2912143926
Publisher: RILEM Publications SARL
Publication year: 2004
Nb references: 16
Language: English

Abstract: This paper describes the use of different characterisation techniques to understand the effect of several chemical admixtures on the microstructural development of cementitious mixtures, and their subsequent effect on strength development. Two sets of admixture systems exhibiting different patterns of strength development in paste, mortar, and concrete - prepared with the same mixture designs were studied. In one case, a polycarboxylate-type superplasticizer (PCP) was added in combination with a calcium nitrite-based corrosion inhibitor, while the other corresponding mixtures included the same corrosion inhibitor, but with naphthalene sulfonate formaldehyde condensate (NSFC) in place of PCP. In order to understand the factors responsible for the difference in strength performance, representative samples were studied by isothermal calorimetry, backscattered electron (BSE) imaging of polished sections in the scanning electron microscope (SEM) and quantitative Xray diffraction (XRD) analysis. All techniques indicated a difference in the degree of reaction of the cement, which appears to be related to strength development. In addition, BSE imaging enabled many aspects of the distribution of the hydration products to be studied – the thickness of the C-S-H rims around the cement grains, the separation of these rims from the underlying grains, and the distribution of calcium hydroxide and calcium sulfo aluminates.

Online publication: 2004-03-25
Classification: Microstructure
Publication type : full_text
Public price (Euros): 0.00
doi: 10.1617/2912143926.007