With the completion of several pilot projects in Hong Kong, Modular Integrated Construction (MiC) is being promoted to boost the productivity and cope with the labour shortage in the local construction industry. However, the possible adverse effects of differential axial shortening due to the time-dependent behaviour arising from concrete creep and shrinkage will only become obvious after a long time. In this study, simplified numerical models are established based on typical hybrid MiC buildings in Hong Kong. Time-dependent analyses considering the creep and shrinkage of concrete are carried out. The construction schedules of the pilot MiC projects are used as a reference to model the staged construction. The results for a 20-storey hybrid MiC building indicate, owing to the concrete creep and shrinkage, noticeable stresses at the module-to-wall connections at the corners of core walls 30 years after construction. The compressive stresses at the bottom of the steel MiC modules will increase substantially over time, which could reduce the amount of material strength that can be utilised by other loads. Hence checking of long-term performance should be conducted at the design stage, particularly focusing on the connections.
Keywords:
Bolted connection; creep and shrinkage; hybrid MiC building; long-term performance; numerical modelling; staged construction analysis
Reference List:
Au FTK and Si XT (2011). Accurate time-dependent analysis of concrete bridges considering concrete creep, concrete shrinkage and cable relaxation. Engineering Structures, 33(1), pp. 118-126.
Bažant ZP and Jirásek M (2018). Creep and hygrothermal effects in concrete structures. Dordrecht: Springer.
Blanc CM, Sánchez AO and Navarro IF (2021). Analytical characterisation of axial shortening due to creep of reinforced concrete columns in tall buildings. Engineering Structures, 228, 111584.
BSI knowledge (2005). BS EN 1992-2:2005, Eurocode 2. Design of concrete structures – concrete bridges. Design and detailing rules. London: British Standards Institution.
Buildings Department (2011). Code of Practice for Dead and Imposed Loads 2011. Hong Kong: The HKSAR Government.
Buildings Department (2013). Code of Practice for Structural Use of Concrete 2013. Hong Kong: The HKSAR Government.
Fédération Internationale Du Béton (fib) (2010). CEB/FIP Model Code 2010. Lausanne: International Federation for Structural Concrete. [online]. Available at: < https://www.fib-international.org/publications/ model-codes.html>.
Construction Industry Council (CIC) (no date). MiC projects: overseas significant projects. [online]. Available at: < https://mic.cic.hk/en/ OverseasProjects>.
Construction Industry Council (CIC) (no date). MiC projects: projects in Hong Kong. [online]. Available at: .
Computers and Structures Inc. (no date). SAP2000 structural analysis and design. [online]. Available at: < https://www.csiamerica.com/products/sap2000>.
WSP Co. Ltd. (2022). InnoCell Wins HKIE Structural Excellence Award 2022. [online]. Available at:
Hong Kong Observatory (no date). Climate of Hong Kong. [online]. Available at: < https://www.hko.gov. hk/en/cis/climahk.htm>.
Kwan AKH, Au FTK, Wong HHC and Ng PL (2010). Shrinkage of Hong Kong granite aggregate concrete. Magazine of Concrete Research, 62(2), pp. 115-126.
Moragaspitiya P, Thambiratnam D, Perera N and Chan T (2010). A Numerical method to quantify differential axial shortening in concrete buildings. Engineering Structures, 32(8), pp. 2310-2317.
Pan W and Hon CK (2018). Modular integrated construction for high-rise buildings. Proceedings of the Institution of Civil Engineers – Municipal Engineer, 173(2), pp. 1-12.
Shan S and Pan W (2020). Structural design of highrise buildings using steel-framed modules: a case study in Hong Kong. The Structural Design of Tall and Special Buildings, 29(15), pp. e1788.
Shan S, Looi D, Cai Y, Ma P, Chen MT, Su R, Young B and Pan W (2019). Engineering modular integrated construction for high-rise building: a case study in Hong Kong. Proceedings of the Institution of Civil Engineers – Civil Engineering, 172(6), pp. 51-57.
Wang Z and Pan W (2020). A Hybrid coupled wall system with replaceable steel coupling beams for high-rise modular buildings. Journal of Building Engineering, 31.
Wang Z, Pan W and Zhang Z (2020). High-rise modular buildings with innovative precast concrete shear walls as a lateral force resisting system. Structures, 26, pp. 39-53.
Zou D, Du C, Liu T, Teng J and Cheng H (2019). Time-dependent deformations of concrete columns under different construction load histories. Advances in Structural Engineering, 22(8), pp. 1845-1854.
Zou D, Liu T, Teng J, Du C and Li B (2014). Influence of creep and drying shrinkage of reinforced concrete shear walls on the axial shortening of highrise buildings. Construction and Building Materials, 55, pp. 46-56.