Effects of blast furnace slag and chemical admixtures on the accuracy of different methods used for the determination of chloride content of Portland cement pastes

Title: Effects of blast furnace slag and chemical admixtures on the accuracy of different methods used for the determination of chloride content of Portland cement pastes
Author(s): D. M. Aleixo, V. A. Quarcioni, S. C. Angulo, W. L. Repette
Paper category : conference
Book title: 2nd International Symposium on Service Life Design for Infrastructures
Editor(s): K. van Breugel, Guang Ye, Yong Yuan
Print-ISBN: 978-2-35158-096-7
e-ISBN: 978-2-35158-097-4
Publisher: RILEM Publications SARL
Publication year: 2010
Pages: 681 - 688
Total Pages: 8
Nb references: 8
Language: English

Abstract: Knowing the free and total chloride amounts in hydrated cement materials is essential for service life of prediction, particularly in the case of reinforced concrete structures. Many factors can influence the free and bound chloride in Portland cement based material: a) CaO/Al2O3 ratio, b) pH solution changed by cement type, and c) sulfonated plasticizers and superplasticizers. This paper aims to analyze the influence of blast furnace slag and water reducing admixtures in the determination of chloride contents of cement pastes. Cement pastes containing different contents of blast furnace slag and fixed concentrations of admixtures (polycarboxylate and lignosulfonate basis) were produced with known chloride amounts. Free and total chlorides were determined by potentiometry using ion-selective electrode. The chloride binding capacity was only noticeable for cement type I (without blast furnace slag) and for lower amount of chloride added (0.1% by mass of binder). The free chloride content drastically increased for additions of chlorides higher than 0.1% by mass of binder, which indicated that the binding chloride capacity reached its saturation amount. The presence of blast furnace slag significantly affected the relative errors for total chloride determinations as well as the presence of polycarboxylate.

Online publication: 2011-04-20
Publication type : full_text
Public price (Euros): 0.00