CIVE 2700 Lecture Notes - Lecture 9: Precast Concrete, Shotcrete, Rebar
4 Apr 2016
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Document Summary
Can make ceiling height higher (or give more floor space) 100-200mpa in strength (normal concrete has strength of 15-125mpa) New and economical for buildings over 30 stories; taller buildings now possible. Reductions in columns and beam dimensions --> slender structures. Design strength increased from 40mpa to 60mpa. Form cycle-time reductions --> more members produced per day. Permits greater spans for girders --> fewer girders for given span. Reduction in size and number of bridge columns and piers --> but bridge deck thickness must increase (large lateral spans) Greater compressive strength per unit cost, mass & volume. Reduced loss of prestress due to lower overall creep and shrinkage strains. Less damage in precast elements during handling and transport. Can get into tight areas - gap filler. Not as many people needed to place it. But requires more care (if any gaps, it"ll pour out) No need for concrete-vibrators (no air pockets) More costly (choice of paying for workers or material)
