1. Influence from ingredients Influence from ingredients W/C W/C Quantity of paste Quantity of paste Sp Sp Aggregates Aggregates Admixture Admixture Influence from environment Time Time Temperature Temperature Test condition Test condition Main influencing factors of Workability

2. 3.Sp  Sp is the ratio of sand to gravel. It determines the void and surface area of aggregates (w and c are fixed). Influence of Sp Main influencing factors of Workability

3. Low Sp Lack of mortar Poor lubrication of the surface of aggregates surface of aggregates Poor lubrication of the surface of aggregates surface of aggregates Poor mobility and tend to segregate tend to segregate Low Sp, may lack mortar, to cause poor lubrication of the surface of aggregates, and poor mobility and tend to segregate

4. Large surface area High Sp Cement mortar for wrapping up sand and filling, lack of paste Cement mortar for wrapping up sand and filling, lack of paste Weak lubrication of the surface of aggregates Low mobility High Sp, high surface area, cement mortar for wrapping up sand and filling, lack of paste, weak lubrication of the surface of aggregates, low mobility.

5. When W and C are fixed, the Optimized Sp makes the composite to gain the highest mobility with favorable viscidity and water retention. Or, the Optimized Sp makes the composite to gain the required mobility with the least cement used. Optimized Sp

6. Slump Sp 优 Sp Amount of cement

7. The Principle of Selecting Sp Method: select Sp based on test and experience. General principle: select small Sp with the guarantee that segregation will not happen and the composite can be placed densely.

8. Select small Sp when gravel has great maximum dimension, proper size distribution and smooth surface Select small Sp when fine sand is used Select small Sp when composite is thick with low w/c Select large Sp when composite has a high mobility avoiding segregation Select small Sp when using admixture Select large Sp when there is a requirement for permeability The Principle of Selecting Sp

9. Low slump High slump Increase the cement paste with fixed W/C Increase the use of aggregates with fixed Sp How to Adjust Workability