Experimental Investigation on Partial Replacement of Concrete in Flexural Member below Neutral Axis

Beam is an important structural member that exists in RC structure. Normally two zones arise in beam, i.e. compression zone at top and tension zone at bottom of simple sup-ported beam. As concrete is weak in tension, steel is introduced in the tension zone to take the tension, so logically no concrete is required in tension side. But concrete is to be provided on tension side to act as a strain transferring media to steel and may be called as ‘sacrificial concrete’. Partial replacement of the concrete below the neutral axis is an idea that can create reduction in weight and savings in materials. In this paper, an experimental investigation on partial replacement of concrete in the tension zone that is be-low the neutral axis by creating air voids. Air voids were created using thermocol. Beams were cast using different percentage of thermocol. The results obtained for control specimens and beams with thermocol are compaired.