HSC Slabs Post-Tensioned with Unbonded Tendons


  • The International Concrete Abstracts Portal is an ACI led collaboration with leading technical organizations from within the international concrete industry and offers the most comprehensive collection of published concrete abstracts.

International Concrete Abstracts Portal


Title: HSC Slabs Post-Tensioned with Unbonded Tendons

Author(s): Bernard Espion and Pierre Halleux

Publication: Special Publication

Volume: 167


Appears on pages(s): 291-310

Keywords: Concrete slabs; continuity (structural); cracking (fracturing); deflection; ductility; flexural strength; high-strength concretes; load tests (structural); post-tensioning; prestressed concrete; unbonded prestressing.

Date: 3/1/1997

This paper reviews the ACI-318 Building Code requirements concerning the design of slabs post-tensioned with unbonded tendons. The design of a simply supported one-way slab is considered in detail. By taking into account all requirements (in service and at ultimate), it is shown that use of high strength concrete results in savings in the number of tendons or in slab depth when compared to a design in normal strength concrete. Tests up to failure of two similar two-span slabs, one in normal strength concrete (f'c = 40 MPa), the other in high strength concrete (f'c = 75 MPa I reveal a better ultimate load behavior for the high strength slab which exhibited more ductility than the normal strength slab. ACI requirements proved to be adequate for estimating the service load and conservative for predicting the actual carrying capacity.