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The effects of loading frequency and stress reversal on the fatigue properties of concrete were investigated by conducting flexural fatigue tests on plain concrete beams. A new fatigue equation based on the classical Aas-Jakobsen S—N equation is proposed which contains the above effects. This equation agrees well with previous experimental results and proves to be suitable for some other loading states other than bending.

Magnetization as a function of field and temperature for a ferromagnetic Heusler alloy Ni 2 MnGa is reported. Magnetization above the Martensitic transition displays a field-dependent peak effect, a direct magnetic evidence of premartensitic phase. At low fields, the peak effect occurs at a temperature consistent with the observations of the micromodulated structure transition seen from neutron scattering, electron microscopy, and ultrasonic studies in this compound. At high fields, the peak effect is suppressed. The strong field dependence of the peak temperature suggests a large magnetoelastic interaction in the intermediate phase.

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Magnetization and transport measurements have been performed to study the martensitic and pre-martensitic transitions for a series of ferromagnetic Heusler alloys. Both magnetization and resistivity measurements show a clear jump at the martensitic transition and a discontinuous slope change at the pre-martensitic transition. The characteristic temperatures correspond well with those derived from previous direct structural results from neutron scattering, electron microscopy and ultrasonic studies. The martensitic transition temperature decreases with increasing Mn concentration.