Abstract:
This work presents the flexural capacities and sustainable analysis of reinforced concrete (RC) two way hollow slabs with polymer sphere voids, also known as polymer bubbled RC slab system. A polymer bubbled RC slab has two-dimensional arrangement of voids included to reduce the self-weight. The strength and behavior of bubbled RC slabs with polymer spheres voids is investigated experimentally. Eleven RC square slabs of 1000mm × 1000mm dimensions have been tested to obtain the flexural behavior. Variables of the experimental work are: diameter of polymer spheres, thickness of reinforced concrete slabs, and percentage of Metakaolin (cement replacement). It has been found that bubbled RC slab, (with ratio of bubble diameter B to slab thickness H, B/H=0.51 to 0.80), has about (90 to 100%) of the ultimate load capacity of a similar reference solid slab (which has the same slab thickness). Also, bubbled slabs consume about (70 to 75%) of the concrete needed for the similar solid slab. An increase in the deflection at 0.7Pu by about (17 to 27%), at the same time, the cracking load is found to be decreased by about (7 to 18%) relative to solid slab system. For approximately the same volume of concrete, the bubbled slabs result an increase in the ultimate load capacity of bubbled slab by about (30%) and a reduction in the deflection at 0.7Pu by about (24%). At the same time, the cracking load is found to be increased by about (29%). The use of Metakaolin (cement replacement) at percentage (10%) gives an increase in the ultimate load capacity of (8%) and a decrease in the deflection at 0.7Pu by (10%). Accordingly, the cracking load is found to be increased by about (18%), in comparison with the reference bubbled slab (without Metakaolin). Analysis of the amount of input raw materials, energy consumption, and CO2 emissions for the polymer bubbled RC slabs, showed that there is a reduction in the amount of the input raw materials used such as sand, gravel and cement up to 45% and this leads to a reduction in the cost of these materials. Sustainable analysis gives a fact that the energy consumption and CO2 emission can be reduced by about (30 to 50%), so it can be said that, the use of bubbled RC slabs is very useful in terms of sustainable building and has important contribution to construct the environmentally friendly buildings. © 2013 International Institute for FRP in Construction.
