Microstructure and Properties of Interfacial Transition Zone in SCC

Title: Microstructure and Properties of Interfacial Transition Zone in SCC
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: 319 - 327
Total Pages: 9
Nb references: 16
Language: English

Abstract: The interfacial transition zone (ITZ) between cement paste and aggregates or reinforcement is an area of particular interest, its association with and significant influence on engineering properties and durability of concrete or cementitious composites being widely recognised. The formation of the ITZ in concrete is due, to a large extent, to a wall effect that prevents effective filling of the space adjacent to the aggregate/reinforcement by cement or other particles, as well as to internal bleeding or settlement in the fresh mix. Considering the different characteristics in particle packing (due to the increase of fine fillers) and the highly flowable and vibration-free placing nature of the SCC, there are general concerns that the ITZs around steel bars and coarse aggregate in structural SCC could be radically different from those in conventional vibrated concrete.
In this paper, the microstructure and properties of the ITZ around coarse aggregate in both SCC and conventional concretes is assessed. Results of micro-mechanical properties of the ITZ obtained by a depth-sensing nanoindentation method appeared to indicate that the ITZ was denser and significantly more uniform in SCC than in conventional vibrated concrete.

Online publication: 2005-04-11
Publication type : full_text
Public price (Euros): 0.00
doi: 10.1617/2912143624.033