Mid-span hollow foam concrete beam

In the design of elevated precast concrete slab, hollow section is often adopted in order
to reduce the selfweight of precast slab. With that idea, this project proposed hollow
beams made of foam concrete and the investigate the performance of beams in terms of
deflection, cracking, and strain. An experimental program including a solid foam concrete
beam and 4 hollow foam concrete beams with different area of hole were tested under
monotonic four point loading until ultimate physical failure. The dimension of beam is
0.15
x 0.2 x 3.0 m. The beam was simply supported during test with use the roller support.
The results of performance for a solid beam and the hollow beams were compared in term
of deflection, cracking, and strain. The strain gauge and linear variable displacement
transducer (LVDT) were used to determine the strain and deflection of beam,
respectively. From this experiment, the result show that the shear failure were occurred
on the foam concrete beam. Therefore, the shear reinforcement or link need to be rectified.
The hollow beam able to withstand until to the design load but will produce more
deflection compare to a solid beam. However, the deflection of
expected to be in the limit stated in code of practice.