Bond strength of textured micropiles grouted to concrete footings

Veludo, J.; Dias-da-Costa, D.; Júlio, E.N.B.S.; Pinto, P.L.

http://hdl.handle.net/10400.8/15334

Use this identifier to reference this record.

Name:	Description:	Size:	Format:
1-s2.0-S0141029611004500-main.pdf		1.43 MB	Adobe PDF	Download

Send Feedback

Authors

Abstract(s)

In a previous research study the authors performed push-out tests with smooth micropile inserts grouted under varying confinement conditions. It was shown that: (i) failure always occurs at the steel-to-grout interface; and (ii) the connection capacity increases with the passive confinement. To increase the connection capacity, it is a common practice to weld steel rings on the surface of the micropile and execute grooves in the predrilled hole. Therefore, a new study is herein presented aiming to widen the conclusions already drawn by analysing the influence of most important parameters in the bond strength of textured micropiles grouted to concrete footings. Laboratory tests were specifically designed for assessing the effect on the connection capacity of the: (i) diameter of the predrilled hole; (ii) insert’s embedment length; (iii) active confinement of the footing; and (iv) treatment of the hole surface. Eighteen textured micropile inserts grouted in RC footings were submitted to monotonic push-out tests until failure. In brief, it can be stated that the capacity of the micropile-to-footing connection increases by increasing the insert’s embedment length and by decreasing the hole diameter. Moreover, an adequate active confinement must be provided to achieve the required capacity.

Keywords

Bond Strength Confinement Retrofitting Interface Micropile Grout Push-out tests

URI

http://hdl.handle.net/10400.8/15334

Citation

J. Veludo, D. Dias-da-Costa, E.N.B.S. Júlio, P.L. Pinto, Bond strength of textured micropiles grouted to concrete footings, Engineering Structures, Volume 35, 2012, Pages 288-295, ISSN 0141-0296, https://doi.org/10.1016/j.engstruct.2011.11.012.