TY - JOUR
T1 - Effect of wall friction on variation of formwork pressure over time in self-consolidating concrete
AU - Kwon, Seung Hee
AU - Phung, Quoc Tri
AU - Park, Hong Yong
AU - Kim, Jae Hong
AU - Shah, Surendra P.
N1 - Funding Information:
This study has been a part of a research project supported by the Korea Ministry of Education, Science and Technology (MEST) via the research group for control of cracks in concrete. The first, second, and third authors wish to express their gratitude for the financial support, while the forth and fifth authors would like to acknowledge financial support from an NSF Award No. CMS-0625606 .
PY - 2011/1
Y1 - 2011/1
N2 - In order to accurately predict the varying of formwork pressure over time, it is necessary to consider various factors influencing the development of formwork pressure. A prediction model has been previously proposed, but that model has some limitations in that only intrinsic material characteristics are taken into account. Extrinsic effects such as wall friction, formwork flexibility, and external temperature are excluded in the model. This study focuses on the wall friction effect as one of the extrinsic factors. First, by incorporating the intrinsic model and friction stress acting on the interface, a method of calculating formwork pressure considering the wall friction effect is suggested. To find out how much friction stress is acting on the interface and how it varies over time, formwork pressure tests were performed with circular column formworks having three different diameters. In these columns, the vertical pressure at the bottom and the lateral pressures were measured. To calibrate parameters of the intrinsic model for the same material as that used in the formwork pressure tests, additional tests were conducted with a specially designed apparatus that can exclude effects of extrinsic factors. From tests and analysis results, it was found that wall friction greatly affects the variation of formwork pressure over time. The newly suggested calculation method can give a good prediction of real formwork pressure.
AB - In order to accurately predict the varying of formwork pressure over time, it is necessary to consider various factors influencing the development of formwork pressure. A prediction model has been previously proposed, but that model has some limitations in that only intrinsic material characteristics are taken into account. Extrinsic effects such as wall friction, formwork flexibility, and external temperature are excluded in the model. This study focuses on the wall friction effect as one of the extrinsic factors. First, by incorporating the intrinsic model and friction stress acting on the interface, a method of calculating formwork pressure considering the wall friction effect is suggested. To find out how much friction stress is acting on the interface and how it varies over time, formwork pressure tests were performed with circular column formworks having three different diameters. In these columns, the vertical pressure at the bottom and the lateral pressures were measured. To calibrate parameters of the intrinsic model for the same material as that used in the formwork pressure tests, additional tests were conducted with a specially designed apparatus that can exclude effects of extrinsic factors. From tests and analysis results, it was found that wall friction greatly affects the variation of formwork pressure over time. The newly suggested calculation method can give a good prediction of real formwork pressure.
KW - Characterization (B)
KW - Formwork pressure (currently nominated)
KW - Fresh concrete (A)
KW - High-performance concrete (E)
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U2 - 10.1016/j.cemconres.2010.09.009
DO - 10.1016/j.cemconres.2010.09.009
M3 - Article
AN - SCOPUS:78649319823
SN - 0008-8846
VL - 41
SP - 90
EP - 101
JO - Cement and Concrete Research
JF - Cement and Concrete Research
IS - 1
ER -