Low-damage technology for sustainable design of high-rise buildings

High-rise buildings have large impact on the community and a significant economic value, considering the resources involved from the design through construction and use. Due to the increasing demand for renewable construction materials, the use of mixed timber-concrete solutions for high-rise structures is attracting more interest: concrete provides adequate stiffness, while timber reduces the embodied carbon of the building, including reductions in construction and demolition waste and improved recyclability. Nevertheless, in earthquake-prone countries, advanced technologies should be used to mitigate the seismic risk of high-rise buildings, considering that slight-to-moderate level of damage can produce substantial economic losses and significant environmental impact. This paper investigates the application of timber-concrete post-tensioned dissipative connections for high-rise buildings in seismic zones. These low-damage connections are able to reduce the post-earthquake residual drift and minimize the damage, thereby reducing direct and indirect losses. Furthermore, dry jointed connections allows for a flexible design approach and advantages in the construction phases. This approach is investigated through two designed case studies: a traditional concrete monolithic (cast-in-situ) building vs. a low-damage timber-concrete solution. Nonlinear dynamic analyses are performed to compare the structural/seismic responses of the case studies. A life-cycle analysis of the two buildings is developed to assess the environmental footprint, also accounting for the probable maximum losses associated with seismic damage. Results demonstrate the great efficacy of the low-damage technology for high-rise buildings: both the post-earthquake economic losses and the environmental impact are reduced by more than 40% when compared to the traditional building system.