Influencing factors of air-void characteristics

Title: Influencing factors of air-void characteristics
Author(s): Yan Shang, Changwen Miao, Jiaping Liu, Qianping Ran
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: 817 - 824
Total Pages: 8
Nb references: 3
Language: English

Abstract: Frost resistance is one of the most important issues to the durability of concrete. And air entraining is the most effective measures to improve the frost resistance. Air-void characteristics are applied to describe the air-entraining properties. Air-entraining, highfrequency vibration and water to cement ratio (w/c) are important influencing factors of air-void characteristics. In this paper, the advanced air void analyzer (MIC-840-01) was used to study the effects of air-entraining, high-frequency vibration and water to cement ratio (w/c) on the characteristics of air void in hardened concrete, including spacing factor, mean air void diameter, specific air void area and air void size distribution, and so on. The results show that air-entraining and w/c make significant effects on spacing factor, mean air void diameter, specific air void area and air void size distribution in hardened concrete. As w/c increases, the spacing factor in hardened concrete increases and the characteristics of air void become worse even though there have the same air contents in fresh concrete, which will influence the frost resistance of concrete. On the other hand, when w/c and the air in fresh concrete are uniform, the air and spacing factor in harden concrete are variant by different air-entraining. Moreover the time of high-frequency vibration have to be controlled in reasonable limits, otherwise it will lead to bad frost resistance.

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