Shear Performance of Board-type Two-way Voided Slab

Title & Authors
Shear Performance of Board-type Two-way Voided Slab
Choi, Hyeon-Min; Park, Tae-Won; Paik, In-Kwan; Kim, Je-Sub; Han, Ju-Yeon;

Abstract
Currently, social demands for long span building structures are increasing due to architectural planning purposes and economic efficiency. As a result, lighter board-type voiding materials were suggested. With the use of board-type voiding materials, a slab is able to become light weight and convenient. This process efficiently eliminates concrete where it is not required; considerably diminishing dead weight while maintaining the flexural strength of the slab. The reduction in concrete also allows for overall cost reductions and design flexibility. Also it can be ease with fixing the voided material that is composed of one body form. Although board-type voiding materials are ideal, the top and bottom concrete plates lack integrity. Because of this, test results show horizontal cracking towards the tops and bottoms of the concrete columns, or webs, connecting the slabs. The key to correcting this problem is to increase the shear strength. In order to increase the shear strength of the structure, horizontal shear area must increase. R70(100)-D-F has the largest horizontal shear area as it also shows stronger strength. As a result, shear strength ($\small{V_{nh}}$) is dependent on the horizontal shear area (N). $\small{V_{nh}={\alpha}{\times}0.16{\sqrt{f_{ck}}}{\frac{{\pi}D^2}{4}}{\times}N({\alpha}=1.8125)}$. The web columns have a shear span to depth ratio (a/d) that is less than 2; which classifies it as a deep beam. In this case, however, the shear strength of the deep beams may be as much as 2 to 3 times greater than that predicated conventional equations developed for members of normal proportions. As a result, $\small{{\alpha}}$ is suggested as an extra coefficient in the equation for shear strength ($\small{V_{nh}}$).
Keywords
performance evaluation;board-type voided slab;fixing material;horizontal shear strength;
Language
Korean
Cited by
References
1.
Ministry of Land, Infrastructure and Transport and Maritime Affairs (Building Planning Division). Floor Impact Sound Insulation structure admit and management criteria in Apartment Houses Enforcement, Act No. 2013-889, 2014, 044-201-3370.

2.
Chung, J. H., Choi, H. K., Lee, S. C., and Choi, C. S., Flexural Strength and Stiffness of Biaxial Hollow Slab with Donut Type Hollow Sphere, Journal of the Architectural Institute of Korea, Vol.30, No.5, 2014, pp.3-11.

3.
Troels Brondum-Nielsen, "Ultimate Flexural Capacity of Cracked Ploygonal Concrete Sections with Circular Holes Under Biaxial Bending", ACI Structural Journal, Vol.84, No.3, 1987, pp.212-215.

4.
Troels Brondum-Nielsen, "Serviceability Limit State Analysis of Concrete Sections with Circular Holes Under Biaxial Bending", ACI Structural Journal, Vol.84, No.4, 1987, pp.293-295.

5.
Tamon Ueda and Boonchai Stitmannaithum, "Shear Strength of Precast Prestressed Hollow Slabs with Concrete Topping", ACI Structural Journal, Vol.88, No.4, 1991, pp.402-410.

6.
Lin, Y., "Design of Prestressed Hollow Core Slabs with Reference to Web Shear Failure", Journal of Structural Engineering, ASCE, Vol.120, No.9, 1994, pp.2675-2696.

7.
Matti, P., and Heli, K., "Shear Resistance of PHC Slabs Supported on Beams. I: Tests", Journal of Structural Engineering, ASCE, Vol.124, No.9, 1998, pp.1050-1061.

8.
Ulf Arne Girhammar and Matti Pajari, "Tests and Analysis on Shear Strength of Composite Slabs of Hollow Core Units and Concrete Topping", Construction and Building Materials, Vol.22, No.8, 2008, pp.1708-1722.

9.
Aldejohann, M., and Schnellenbach-Held, M., "Investigations on the Shear Capacity of Biaxial Hollow Slabs-Test Results and Evaluation", Darmstadt Concrete, Vol.18, 2003, pp.1-11.

10.
Kim, S. M., Jang, T. Y., and Kim, S. S., "Structural Performance Tests of Two-way Void Slabs", Journal of the Architectural Institute of Korea, Vol.25, No.8, 2009, pp.35-42.

11.
Kang, J. Y., Kim, H. G., Joo, E. H., Kim, S. M., Kim, H. S. and Shin, Y. S., "Experimental Studies on the Effect of Construction Methods on Shear Strength of Hollow Core Slab", Proceedings of the Korea Concrete Institude, Vol.23, No.1, 2011, pp.15-16.

12.
Martina, S., and Markus, A., Biaxial Hollow core slabs - theory and tests, Bentonwerk, Fertigteil Technic, 2005, section 50-59.