Sensory fields, self-reflection and the future
3.8 Sustainable form-inclusion systems (SFIS) 3.9 Parametric city model, illustrating darker areas where occupied efficiency falls below targets 3.10 Construction, Poly International Plaza, Beijing (CN) 2015 3.11 Diagram of facade, Poly International Plaza 3.10
overall plan as the requirements for building systems and structure vary when comparing, for example, office, residential and mixed use occupancies (Fig. 3.9). Rheological buildings for the future The envelope enclosure for structures represents the single greatest opportunity to consider flow and interaction between architectural, structural and building service systems (Figs. 3.10 and 3.11). Hundreds of millions of square metres of occupied area are enclosed each year with systems that essentially provide protection from the elements, safe occupancy and internal comfort. A closed-loop structural system integrated into an exterior wall and roof system that incorporates liquid-filled structural elements could provide a thermal store that heats up during the day and could be used for building service systems – such as a hot water supply or heat for occupied spaces – during the evening hours. A solar collection system could be integrated into the network and incorporated into double wall systems, where it could be used to heat the internal cavity in cold climates. Transparent photovoltaic cells could be introduced into the glass and spandrel areas to capture more of the energy of the sun.
The concept of flow can be further developed into structures that are interactively monitored for movement. Through the measurement of imposed accelerations due to ground motions or wind, structures could respond by changing the state of the liquid within the system. For instance, the structure could use endothermic reactions to change liquids to solids within the closed network. Sensor devices could inform structural elements of imminent demand and initiate a state change in liquids that could be subjected to high compressive loads during which buckling could occur. Magnetorheological or electrorheological (ER) fluids could be used to change the viscosity and therefore the stiffness of closed vessels and their damping characteristics. When subjected to a magnetic field, magnetorheological fluids greatly increase their apparent viscosity and can become viscoelastic solids. When subjected to an electrical field, ER fluids can reversibly change their apparent viscosity quickly, transitioning from a liquid to a gel and back again.
When storing liquids in very tall structural systems, pressures within the networked vessels become very large. With this level of pressure, for example, water could be supplied to the structure or to neighbouring structures of lesser height without requiring additional energy to move it. The energy required to store the water initially is minimised if water was collected at upper levels of the building, particularly roof and upper exterior wall areas. A continuous low velocity flow or a liquid with a low freezing point passing through these systems would keep it from freezing. Liquid in tuned-liquid dampers within the networked system would control motion, with fluid flow acting to dampen the structure when subjected to lateral loads from wind and earthquake events. 3.11
51