Influence of superplasticizers and mineral admixtures on the workability of mortar at low water-binder ratio

Author(s): Jiangzhong Liu, Wei Sun, Changwen Miao, Qianqian Zhang, Jiaping Liu,
Paper category: Conference
Book title: 2nd International conference on Microstructural-related Durability of Cementitious Composites
Editor(s): Guang Ye, K. Van Breugel, Wei Sun, Changwen Miao
Print ISBN: 978-2-35158-129-2
e-ISBN: 978-2-35158-123-0
Publisher: RILEM Publications SARL
Pages: 1377- 1385
Total Pages: 8
Language: English

The workability of concrete with low water-binder ratio is usually poor and the concrete mixture is sticky, which lead to hard placement and increase of cost. Workability of concrete is related to superplasticizers and mineral admixtures, which are important constituents in the concrete at low water-binder ratio. In this work, with the workability characterized by flow spread, V-Funnel flow time, rheology, the influences of the superplasticizers (PCA1, PCA2 and PCA3) and mineral admixtures (fly ash, slag and silica fume) on the workability of fresh mortar at the water-binder ratio of 0.2 were investigated. The results show that PCA3 was more effective in improving the workability than PCA1 and PCA2 for mortar at low water-binder ratio. At the same flow spread of the mortar, addition of fly ash reduced the demand of superplasticizer, V-Funnel flow time and rheological parameters. However, the addition of slag resulted in an increased demand of superplasticizer and decreased flow time and rheological parameters. The addition of silica fume increased the demand of superplasticizer and plastic viscosity, but decreased the yield stress.

Online publication: 2013
Publication Type: full_text
Public price (Euros): 0.00