Steel Window Framing..
Pre-cast concrete panels...
Connections...
Concrete and steel work
Tilt-up concrete panels..
Looks quite irrelavant to the topic of high rise commercial buildings, yet interesting steel construction...
Slab Alternatives From Recycled Waste (Architecture 04/2006) describes two proprietary Swiss systems from using recycled waste products in concrete to provide lighter-weight, better-performing concrete products.
Cobiax Technologies manufactures a system of hollow recycled polyethylene plastic spheres integrated with steel reinforcing cages that may be used to construct sitecast or "semi-precast" concrete floor slabs. This slab system can span from approximately 5 to 20 meters (15 to 65 feet) with thicknesses ranging from 230 to 580 mm (9 to 24 inches), capabilities roughly comparable with sitecast concrete one-way joist systems or precast concrete hollow core slabs.
In comparison to conventional concrete systems, the manufacturer claims weight savings of up to 35%, and additional potential savings through reduction in construction time and simplification of concrete forming requirements.
Geofil manufacturers glassy spheres from recycled waste, with sizes ranging from 2 to 25 mm (1/16 to 1 inch) in diameter. When added to concrete, the manufacturer claims a lighter-weight material with improved heat resistance and higher insulating values is produced.
Extracted from - http://www.ianosbackfill.com/sustainability/index.html