Development of Prestressed Concrete Using Fe-Mn-Si-Based Shape Memory Alloys Containing NbC

Abstract

This article reports the mechanical properties of the concrete prestressed by the Fe Mn Si based shape memory alloys containing NbC that exhibit an excellent shape memory effect without so called the``training'' treatment. A thermomechanically treated Fe 28Mn 6Si 5Cr 0.53Nb 0.06C(mass) alloy was used for this purpose. Four rectangular shaped specimens were embedded in mortar, and heated at above their reverse martensitic transformation start emperature after hardening of the mortar matrix. Three point bending tests were performed for the mechanical property characterization. It was found that prestressing by the shape memory alloys increased the bending stress and cracking stress of mortar.

Recovery stress formation in a restrained Fe–Mn–Si-based shape memory alloy used for prestressing or mechanical joining

“…Although a number of studies were conducted with regard to the shape recovery and recovery stress formation in Fe-SMAs from a fundamental perspective [20][21][22][23][24], several practical issues were not considered in the literature. One important issue is the development of the recovery stress under non-ideal restraints during the installing process or the activation of SMA components.…”

Recovery stress formation in FeMnSi based shape memory alloys: Impact of precipitates, texture and grain size

“…The shape memory effect (SME) in FeMnSi based alloys was first discovered by [1][2][3]. Due to low costs, high recovery stresses and its damping capacity the material is considered for use in civil engineering as prestressing or damping element [4][5][6][7][8][9]. The SME is based on the stress-induced austenite fcc (γ) to martensite hcp (ε) transformation.…”

Thermomechanically micromechanical modeling of prestressed concrete reinforced with shape memory alloy fibers

“…Following them, Deng et al (2003Deng et al ( , 2006 studied the effect of different properties, such as initial prestrain of SMA wires, modes of activating electrical current, and the actuation times, on the behavior of prestressed beam. Recently, El-Tawil and Ortega-Rosales (2004) and Sawaguchi et al (2006) examined different experimental aspects of the post tensioning procedure. Finally, in case of thin walled members, and for small tension stresses, the use of SMA bars is not feasible anymore; for this purpose, SMA fibers may be embedded in the cement matrix, as suggested by Moser et al (2006).…”