Investigation on shrinkage cracking of economical Self-Compacting Concrete

Title: Investigation on shrinkage cracking of economical Self-Compacting Concrete
Author(s): W. Zhu
Paper category : conference
Book title: SCC'2005-China: 1st International Symposium on Design, Performance and Use of Self-Consolidating Concrete
Editor(s): Zhiwu Yu, Caijun Shi, Kamal Henri Khayat and Youjun Xie
Print-ISBN: 2-912143-61-6
e-ISBN: 2912143624
Publisher: RILEM Publications SARL
Publication year: 2005
Pages: 507 - 516
Total Pages: 10
Nb references: 8
Language: English

Abstract: In this paper, novel ellipsis-ring cracking apparatus with an automatic monitoring system was used to test initial cracking time of mortar sieving from Self-Compacting Concrete (SCC) to estimate its cracking sensitivity. Free shrinkage, compressive strength, and workability were integrated to evaluate the influence of content of fly ash (FA) and multiple adding of FA and silica fume (SF) as well as total binders on shrinkage cracking property of SCC. The results showed that fluidity of FA SCC was improved due to its shape effect. Cohesiveness and homogeneity of SCC was increased significantly when combined SF and FA due to its large surface of SF, that is to say, multiple adding of FA and SF achieved excellent SCC with synergistic effects of them. High efficiency superplasticizer and higher dosage were needed when SF was used in SCC. Initial cracking time of mortar incorporating FA was delayed and cracking sensitivity of SCC was decreased apparently comparing to the control sample, shrinkage value and rate was reduced with the increase of FA content. The rapid hydration of SF contributed to increase cracking sensitivity of binary binders incorporating cement and FA in drying-stored condition, but compressive strength of SCC at early-age was increased which is beneficial to cracking resistance ability under the restrained condition. For SCC with the same strength grade, the initial cracking time of SCC was delayed and cracking sensitivity was decreased markedly with the decrease of total binders, especially when it achieved 450kg/m3. It was founded in this research SF acted as a fine stabilizer for SCC, in particular at a low content of total binders.

Online publication: 2005-04-11
Publication type : full_text
Public price (Euros): 0.00
doi: 10.1617/2912143624.054