Synopsis
The inelastic behaviour of ferrocement slabs in bending is studied analytically and experimentally with particular reference to rectangular slabs under cylindrical bending and circular slabs under central load applied through a boss. Analytically, the ferrocement slab is treated as an elastic-strain-hardening material with a limit surface. Its moment-curvature relationships are derived on the assumption that the wire mesh yields as soon as it is impinged by a crack. These relationships lead to an idealized trilinear moment-curvature curve which is used in the analytical study. The load-deformation up to the ultimate loads of the rectangular slabs under cylindrical bending is predicted by means of this trilinear analysis. For the circular slabs under central load applied through a boss, the trilinear analysis is used to predict the deflections up to the load level beyond which non-regular progression of stress points occurs. The laborious and time-consuming calculations associated with the solution involving non-regular progression of stress points is avoided by the observation that, at higher loads, the deflections of the ferrocement slabs can be approximated by an elastic-perfectly-plastic bilinear analysis. Experimental results are shown to be in good agreement with theoretically predicted values.
