Title:
Robustness of Self-Consolidating Concrete Incorporating Different Viscosity-Enhancing Admixtures
Author(s):
Siwar Naji, Soo-Duck Hwang, and Kamal H. Khayat
Publication:
Materials Journal
Volume:
108
Issue:
4
Appears on pages(s):
432-438
Keywords:
humidity; polycarboxylate; polynaphthalene; polysaccharide; saturated surface dry; self-consolidating concrete; viscosity
DOI:
10.14359/51683116
Date:
7/1/2011
Abstract:
Given the sensitivity of self-consolidating concrete (SCC) to small variations in raw material characteristics, more care should be taken for the selection of constituent materials and mixture proportioning to secure adequate robustness. An experimental program was undertaken to evaluate the robustness of SCC subjected to variations in sand humidity. Eight groups of SCC mixtures with various combinations of viscosity-enhancing admixtures (VEAs) and high-range water-reducing admixtures (HRWRAs) were tested. For each group, mixtures with sand humidity corresponding to saturated surface-dry (SSD) condition and ±1% humidity were prepared. The tested mixtures were ranked in terms of robustness using the values of the coefficient of variation (COV) for all 20 of the properties investigated. A statistical approach was then used to reduce the number of properties that could provide a similar ranking of robustness. The test results show that the use of microbial anionic polysaccharide VEAs can provide greater robustness than cellulose-based VEAs. In the case of mixtures made without any VEA, SCC incorporating polynaphthalene sulfonate-based HRWRA was found to be more robust than similar SCC prepared with polycarboxylate ether-based HRWRA.