Title:
Prestressing Concrete Using Shape Memory Alloy Tendons
Author(s):
Sherif El-Tawil and Juan Ortega-Rosales
Publication:
Structural Journal
Volume:
101
Issue:
6
Appears on pages(s):
846-851
Keywords:
concrete; post-tensioning; prestress
DOI:
10.14359/13460
Date:
11/1/2004
Abstract:
This paper discusses the use of shape memory alloy (SMA) tendons to prestress concrete. The research is motivated by the opportunity of achieving convenient and simple post-tensioning—that is, without jacking equipment—and by the possibility of significantly reducing prestress losses. Tensile tests are first performed on two types of SMA tendons to determine basic tensile properties, constrained recovery stresses for various prestrain levels, and transformation temperatures. Prestressing SMA tendons are then prestrained, placed in mortar beams, and heat-triggered after beam curing to induce a post-tensioning effect. Results from four-point loading beam tests demonstrate that significant prestressing was achieved. The viability of prestressing concrete using SMA is discussed from both structural and economic view points. Various other practical issues are also discussed.