Precast vs. In-situ

 Continuity, continuity, continuity  Structural performance  SLS  Deflection & cracks  ULS  Robustness  Design consideration  Structural system/form  Design for the entire life-span of member  Casting, storage, transport, lifting, installation  Joint design and checking  Stability check  $, $, $  Efficient Design Workflow

 Members are “segmented”  Discontinuity exist between members  Disrupted flow of forces  Additional checking and detailing  Use of proprietary connectors (pricey!)

Semi-precast !!!

Semi-precast beams with pockets

Precast columns with wet joints

 SLS d1 d2 d2 > d1

 SLS

 ULS : Robustness Detailing + code provisions

 Determine structural form based on usage  Industrial ?  corbels, pre-stressed beams, hollow core slabs …  Residential ?  half-slab, semi-precast beams and columns …

 Casting  Storage  Transportation  Hoisting  Installation / tolerance  Construction load  Permenant & quasi-permanent loads

Storage : mis-alignment of supports Temporary Storage / flipping : side-standing

Hoisting : unbalanced lifting points Construction temporary loading In-service loading with toppings mmmmmmmmmmmmmmmmmm

 Corbel : strut-and-tie method  Semi-precast : pre-embeded vs. on-site

 Horizontal shear  Vertical Tie  Bearing  Dowel connector  Splice sleeves  Spiral Connectors

 Avoid mechanism during construction and service

 Repetition matters  Modular coordinated  Golden ration between precast and in-situ pour  Within crane hosting capacity

 Pre-design members of various sizes and dimensions (calculation + testing)  Choose and invent joint system that provide in- situ class continuity  Analyze structure as in-situ  Pick the right members based on analysis results  Join the members using the chosen joint system  “Lego”  Integrated software that assisting in doing all the above