Effect of Mixture Consistency on Formwork Pressure Exerted by Highly Flowable Concrete
Publication: Journal of Materials in Civil Engineering
Volume 18, Issue 6
Abstract
An experimental program was undertaken to evaluate the effect of a mixture’s consistency on the lateral pressure that can be developed by highly flowable concrete. Six mixtures, with various contents of high-range water-reducing admixtures, were tested and had consistency levels varying between a slump of and a slump flow of . The mixtures had similar water-to-cementitious materials and sand-to-total aggregate ratios of 0.40 and 0.46, respectively. Depending on the mixture consistency, the maximum initial pressures varied between 75 and 98% of hydrostatic. Concretes with lower consistency were shown to exert lower initial lateral pressure and had faster rates of pressure drop with time. This can be attributed to the increased degree of shear strengths that enables the fresh concrete to further resist vertical stresses, hence precluding the development of high lateral pressure. Self-consolidating concrete mixtures made with standard CSA Type 10 cement exhibited higher initial pressure and lower rates of pressure drop compared to those of equal consistency prepared with ternary cement. At the end of the dormant period of cement hydration, the acceleration of formation of hydrates is shown to enable the concrete to be self-bearing—resulting in the cancellation of lateral pressure.
Get full access to this article
View all available purchase options and get full access to this article.
References
Assaad, J., and Khayat, K. H. (2004). “Variations of lateral and pore water pressure of self-consolidating concrete at early age.” ACI Mater. J., 101(4), 310–317.
Assaad, J., and Khayat, K. H. (2005). “Formwork pressure of self-consolidating concrete made with varous binder types and content.” ACI Mater. J., 102(4), 215–223.
Assaad, J., Khayat, K. H., and Mesbah, H. (2003). “Assessment of thixotropy of flowable and self-consolidating concrete.” ACI Mater. J., 100(2), 99–107.
Baudeau, P. (1983). “Contribution in study of rheological behavior of concrete in high vertical form faces before setting of cement.” Doctoral thesis, Univ. Louis Pasteur de Strasbourg, France, 1–168 (in French).
Gardner, N. J. (1980). “Pressure of concrete against formwork.” ACI J., 77(3l), 279–286.
Manai, K. (1995). “Evaluation of the effect of chemical and mineral admixtures on the workability, stability, and performance of self-compacting concrete.” MS thesis, Univ. de Sherbrooke, Canada, 1–182 (in French).
Ore, E. L., and Straughan, J. J. (1968). “Effect of cement hydration on concrete form pressure.” ACI J., 65(9), 111–l20.
Petersson, Ö., Billberg, P., and Van, B. K. (1996). “A model for self-compacting concrete.” Proc., Int. RILEM Conf. on Production Methods and Workability of Concrete, P. J. M. Bartos, et al., eds., Chapman and Hall, Paisley, 483–490.
Ritchie, A. G. B. (1962a) “The pressures developed by concrete on formwork. Part 1.” Civ. Eng. Public Works Rev. 57, 24–33.
Ritchie, A. G. B. (1962b). “The pressures developed by concrete on formwork. Part 2.” Civ. Eng. Public Works Rev., 57, 1–10.
Rodin, S. (1952). “Pressure of concrete on formwork.” Proc. Inst. of Civ. Eng. (UK), 1(6), 709–746.
Information & Authors
Information
Published In
Copyright
© 2006 ASCE.
History
Received: Mar 5, 2004
Accepted: Dec 28, 2005
Published online: Dec 1, 2006
Published in print: Dec 2006
Notes
Note. Associate Editor: Zhishen Wu
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.