The effect of water-cement ratio, sulphonated plasticizer and silica fume on delayed ettringite expansion

Title: The effect of water-cement ratio, sulphonated plasticizer and silica fume on delayed ettringite expansion
Author(s): B. Lagerblad, P. Utkin
Paper category : conference
Book title: International RILEM Workshop on Durability of High Performance Concrete
Editor(s): H. Sommer
Print-ISBN: 2-912143-03-9
e-ISBN: 2351580125
Publisher: RILEM Publications SARL
Publication year: 1994
Pages: 154 - 173
Total Pages: 20
Nb references: 14
Language: English

Abstract: This investigation concerns the effect of low waterlcement ratios, sulphonated superplasticizers and silica fume on expansion caused by delayed ettringite formation. Delayed ettringite reaction is induced by high curing temperatures and results in ettringite reformation in hardened concrete when subjected to moisture. The resulting expansion can be deleterious to concrete.
In this investigation Mortar prisms have been subjected to curing temperatures of 60, 75 and 95" C. The results show, that with a cement moderately high in alumina and alkalies, expansion occurs at a temperature above 60 but below 75" C The critical temperature is not effected by the sulphonated plasticizers (melamine- and naphtalene-based) Lower wlc ratios delay the expansion but do not stop the reaction Silica fbme both delays and ecreases the expansion The only method of hindering the reaction, if the curing temperature is more than 60" C, is to use a cement with low aluminate and alkali contents

Online publication: 1996-02-02
Publication type : full_text
Public price (Euros): 0.00
doi: 10.1617/2351580125.017