【正文】
y proportioned concrete ? Shear slump ? Concrete lacks plasticity and cohesion ? Collapse slump ? Lean, harsh or extremely wet concrete Remended slumps for various type of construction Type of construction Slump (mm) Max Min Footings, caissons, foundation walls and substructure walls 75 25 Beams, columns and walls 100 25 Pavement and slabs 75 25 Mass concrete 50 25 Factors affecting Consistency and Workability ? Internal Factors ? Cement properties ? Proportion of cement, Types of cement, Fineness ? Aggregate properties ? Surface area of aggregate, shape, gradation, maximum size of aggregate ? Water content ? WatertoCement ratio 水灰比 ? Admixtures ? Waterreducing admixture, airentraining admixture 減水劑、引氣劑 Factors affecting Consistency and Workability ? External Factors ? Environment ? Temperature, humidity, wind speed