Li et al. / J Zhejiang Univ-Sci A (Appl Phys & Eng) 2012 13(3):165-173 165 Moment transfer factors for column-supported cast-in-situ hollow core slabs * Hai-tao LI †1 , Andrew John DEEKS †‡2 , Li-xin LIU 3 , Dong-sheng HUANG 1 , Xiao-zu SU 4 ( 1 Department of Building Engineering, Nanjing Forestry University, Nanjing 210037, China) ( 2 Faculty of Science, Durham University, Durham, DH1 3LE, England) ( 3 Department of Civil Engineering, Zhengzhou University, Zhengzhou 450002, China) ( 4 Department of Building Engineering, Tongji University, Shanghai 200092, China) † E-mail: lhaitao1982@126.com; a.j.deeks@durham.ac.uk Received June 22, 2011; Revision accepted Oct. 18, 2011 ; Crosschecked Feb. 7, 2012 Abstract: Hollow core slabs are becoming of increasing interest as the construction industry attempts to minimise the impact of its activities on the environment. By forming voids in the interior of a concrete slab, the amount of concrete used can be reduced without significantly altering the capacity of the structure. In this study, we examined the inner force transfer mechanism of a column-supported cast-in-situ hollow core slab using finite element analysis. Both a hollow core slab and the corresponding solid slab were analysed using ANSYS and the results were compared. The orientation of the tube fillers causes the stiffness of the hollow slab to be orthotropic, potentially changing the distribution of load carried in the two orthogonal directions. Both the cross-section’s moments in the column strip and near the columns in the hollow core slab become larger than that in the solid floor. As well, the cross-section’s stiffness along the tube arrangement direction is larger than that of the radial cross-section, which causes the direction along the hole of the hollow core slab to carry more moment than the radial direction. The conversion factors of the two directions are proposed from the comparison for four typical areas of the hollow core slab, as are the moment distribution coefficients. Key words: Reinforced concrete, Cast-in-situ, Hollow core slab, Tube filler, Finite element analysis doi:10.1631/jzus.A1100170 Document code: A CLC number: TU973 + .14 1 Introduction The impact of the construction industry on the environment is becoming an increasing global concern. In particular, the contribution of cement production to carbon emissions has come under scrutiny. In turn this has raised interest in methods of increasing the efficiency of concrete usage. Much of the load resisted by a concrete structure is the weight of the structure itself. Reducing the weight of the structure not only saves concrete directly, but also potentially allows reduced structural sections, as the dead load is correspondingly reduced. Hollow concrete floors are therefore, becoming of increasing interest in building construction. By forming voids in the interior of a concrete slab, the amount of concrete used can be reduced without significantly altering the capacity of the structure. The cast-in-situ hollow core slab was first suggested by Leopold MOLLER in the 1960s, and was named the B-Z system (Fertigteil-Vertrieb Gmbh, Mannheim, 1965). This cellular hollow core slab structure was studied through a series of experiments performed by Franz (1965). A method Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering) ISSN 1673-565X (Print); ISSN 1862-1775 (Online) www.zju.edu.cn/jzus; www.springerlink.com E-mail: jzus@zju.edu.cn ‡ Corresponding author * Project supported by the Australian Research Council Research Grant (No. DP0988940), the Natural Science Foundation of Jiangsu Province (No. BK2009394), the China Postdoctoral Science Foundation (No. 2011M500930), the Natural Science Surface Project of Jiangsu Provincial Universities (No. 11KJB560003), and the Talent Introdu- ction Fund of Nanjing Forestry University (No. 163050072), China © Zhejiang University and Springer-Verlag Berlin Heidelberg 2012