Comparison of Cracking s Ultimate Moment Capacity of Hollow RCC Beam with Same Size of Solid RCC Beam

Abstract

Construction industry in PAKISTAN is passing through a rapid change whereby the existing knowledge of engineering principles, to introduce new construction techniques for building lighter structures without impairing their strength and durability seems to be insufficient. Deflection of a structural member while taking loads are somewhat related to its self weight, and if the self weight is reduced, obviously its deflection will be less. For the same density of material used self weight can be reduced by introducing hollowness in the member cross-section and this hollowness creation should be such that its strength and other important parameters are comparable with that of same size solid structural member. This is most appropriately possible in RCC beams where it is easy to eliminate use of concrete below neutral axis thus creating hollowness without reduction of its load taking capacity. Doing so hollow RCC beams will prove more economical because of less self- weight and causing less load on columns and foundations. With above in view, this experimental study was undertaken to prove that a hollow RCC beam by omitting concrete below the neutral axis gives comparable strength as that of a solid beam having same cross-sectional dimensions and same span length. The results obtained through this study are quite encouraging and will prove a guide in designing and providing hollow beams in future constructions. 1.2) PROJECT DESCRIPTION The project is aimed at testing hollow and solid RCC beams of same dimensions and span length so as to compare their load taking capacity at different limit states. 1.3) AIM AND OBJECTIVE Basic objective of this project is to bring economy by using less material without reduction in strength. This use of less material will reduce overall weight of the structure and therefore will result in smaller sizes of other members too. Intensive investigations have, however,