Experimental Study on Voided Biaxial Slab and it

Slab is largest member which consumes concrete. If the load acting on the slab is large or clear span between columns is more, the thickness of slab increases. It leads to consume more material such as concrete and steel due to this, self-weight of slab is avoid these disadvantages voided slab system is used. Reinforced concrete slab with plastic voids is a new and innovative type of construction. It is developed to allow for lighter self-weight of the structure while maintaining similar load carrying capacity of a solid slab. High density polyethylene (HDPE) hollow spheres replace the ineffective concrete from the centre of the slab and decrease the dead load. The advantages are less energy consumption both in production and transport, less emission of exhaust gases from production and transport, especially CO2 and reduce the material, the load, lower the cost and it is also a Green Technology. The Bubble deck slab floor system can be used for storey, roof and ground floor slabs. The effect is to decrease the overall weight by as much as 15% when compared to a solid slab of the same bearing capacity.


INTRODUCTION
Slab is very important member of construction. It is one of the largest member consuming concrete. The main obstacle with concrete @ IJTSRD | Available Online @ www.ijtsrd.com | Volume -2 | Issue -1 | Nov-Dec 2017 Slab is largest member which consumes concrete. If the load acting on the slab is large or clear span between columns is more, the thickness of slab increases. It leads to consume more material such as concrete and increased. To avoid these disadvantages voided slab system is used. Reinforced concrete slab with plastic voids is a new and innovative type of construction. It is developed to weight of the structure while carrying capacity of a solid slab. High density polyethylene (HDPE) hollow spheres replace the ineffective concrete from the centre of the slab and decrease the dead load. The advantages are less energy consumption both in production and ission of exhaust gases from production and transport, especially CO2 and reduce the material, the load, lower the cost and it is also a Green Technology. The Bubble deck slab floor system can be used for storey, roof and ground floor slabs. The to decrease the overall weight by as much as 15% when compared to a solid slab of the same bearing Slab is very important member of building construction. It is one of the largest member consuming concrete. The main obstacle with concrete constructions, in case of horizontal slabs, is the high weight, which limits the span. So it is necessary to focused on weakness of the span, reducin or overcoming concrete's natural weakness in tension. In a general way, as the span is increased the deflection of the slab is also increased. Therefore, the slab thickness should be increase. Increasing the slab thickness makes the slabs heav column and foundation size. Thus, it makes buildings uneconomical. To avoid these disadvantages which were caused by increasing of self voided slab system is used.
A voided slab is a concept that simply removes t excess concrete from the expensive part of the structure slab. Bubble deck slab is the application of voided slab. It is a method of eliminating all concrete from the middle of a floor slab, which is not performing any structural function. High density hollow spheres replace the ineffective concrete from the centre of the slab and decrease the dead load. introducing the gaps it leads to 10 to 3 It can also be used as a fire resistant structure. waste is non-degradable and its disposal has become a matter of great concern to the environment. constructions, in case of horizontal slabs, is the high weight, which limits the span. So it is necessary to focused on weakness of the span, reducing the weight or overcoming concrete's natural weakness in tension. In a general way, as the span is increased the deflection of the slab is also increased. Therefore, the slab thickness should be increase. Increasing the slab thickness makes the slabs heavier, and will increase size. Thus, it makes buildings avoid these disadvantages which were caused by increasing of self-weight of slabs, the A voided slab is a concept that simply removes the excess concrete from the expensive part of the structure slab. Bubble deck slab is the application of voided slab. It is a method of eliminating all concrete from the middle of a floor slab, which is not performing any structural function. High density polyethylene (HDPE) hollow spheres replace the ineffective concrete from the centre of the slab and decrease the dead load. By troducing the gaps it leads to 10 to 30% lighter slab. It can also be used as a fire resistant structure. Plastic degradable and its disposal has become a matter of great concern to the environment. The reduced weight of the slab allows for longer slabs between columns without beams and a reduction in concrete and steel in floors, columns, and footings, saving money and reducing the total building weight, allowing lighter foundation also using recycled material. The uses of SSC increase the punching shear strength and reduce the mid span deflection. Punching shear strength is increased in voided SCC slab and the mid deflection decreased. Adding steel fibre at the critical zone increased the punching strength and reduced the angle of punching failure. The crack pattern of punching shear reduced by use the SCC.
L. R. Terec and M. A. Terec:-The studies have demonstrated that, with the same amount of concrete and the same reinforcement as the solid slab, the bubble deck configuration allows the obtaining of a much-improved flexural capacity and stiffness and a shear capacity of at least 70% from that of a solid slab, realizing 30-50% concrete economy, in comparison with the solid slab. Another advantage of bubble deck system is the significant cost saving.
Wondwosen B. Ali and Girum S. Urgessa (2013):- The stiffness for deflection of short span SVBS is considerably less than solid slabs; however, the stiffness becomes almost equal for large span slabs.  The flexural capacity of SVBS under uniform load is very close to that of solid slabs, it gets even closer as the span gets longer.  The punching shear capacity of SVBS is considerably less than solid slab; hence, the practice of not placing void formers around columns is plausible.  Imparting spherical voids around the middle region of the slabs does not significantly compromise the flexural capacity and deflection behaviour of slabs; however, it provides considerable material savings.

RESULTS
The quantity of fine aggregate, course aggregate, cement and W/C ratio is given below:- 2) Weight reduction is 25% compared to solid slab.
3) The bubble deck technology is environmentally green and sustainable; avoiding the cement production allows reducing global CO2 emissions.
4) Cost and time saving by using bubbles in the slab like weight of slab, concrete volume indirectly load on the beam and walls also decrease less so that building foundations can be designed for smaller dead loads.

5)
In comparative of conventional slab the volume of concrete in bubble deck are less required, that is 25% approximately.
6) Voided slabs eliminate concrete where it isn't needed, the reduced weight of the slab.
7) The stiffness for deflection of short span SVBS is considerably less than when compared to conventional than solid slabs; however, the stiffness becomes almost equal for the large span.
8) The flexural capacity of SVBS under uniform load is very close to that of solid slabs, it gets even closer as the span gets longer.
9) The punching shear capacity of SVBS is considerably less than solid.