Energy efficiencies of linear-shaped multi-residential apartment buildings built with hybrid structural systems

The construction industry requires significant materials and energy, and has some of the most pressing needs for energy-saving initiatives to support sustainable development. This paper studies energy efficiency during the construction of structural systems for multi-residential apartment buildings using composite structural systems. For this purpose, nine linear-shaped apartment buildings originally designed as bearing wall systems were designed as flat slabs and hybrid composite frames to study the energy consumptions of such buildings during the construction phase. The energy consumptions were then compared in terms of structural system, number of floors, and area. The energy-efficient hybrid frame used structural steel, cast-in-place concrete, and precast concrete. The structural system proposed in this paper is intended to reduce energy consumption through the proper combination of structural steel, cast-in-place concrete, and precast concrete. It was found that a multi-residential apartment building constructed with an energy-efficient hybrid composite frame could save approximately 20% of the construction phase energy used in the conventional bearing wall system. This energy savings was made possible by the reduced use of form-work resulting from the utilization of precast members, and the reduced consumptions of steel and concrete resulting from the enhanced structural performance of the hybrid composite system. The energy-efficient hybrid structural system is expected to be an alternative for future multi-residential apartment buildings.