1. We should abide by the principle of selecting low mobility with the guarantee of construction operation and placing densely. §4.3.4Selection and Classification §4.3.4 Selection and Classification of Composite Slump Principle Selection Select mobility according to member cross section, condensing methods and reinforcement spacing.

2. The high slump in the condition of small cross section, manual condensing and small reinforcement spacing.

3. Tab4.3.1 Slump selection for concrete structure (vibrated by machine) Slump (mm) TypeApplication >160 Large viscidity Pumping concrete, structures with narrow transact and reinforcing steel bar distributed especially densely 100-150 Viscidity Pumping concrete, structures with narrow transact and reinforcing steel bar distributed densely 50-90 Plasticity Normal concrete structure 10-40 Low plasticity Vibrate intensely, prefabricate member, base and steel in less thick structure