 Relation between water/cement ratio and average compressive strength of concrete (Fm) 

average compressive strength at 28 days (kg/cm^{2})  effective water/cement ratio(by mass) {NonAirentrained Concrete}  effective water/cement ratio(by mass){Airentrained Concrete}  350  0.48  0.4  300  0.55  0.46  250  0.62  0.53  200  0.7  0.61  150  0.8  0.71 
Relation between water/cement ratio and average specified compressive strength of concrete (Fcu) 

average compressive strength at 28 days (kg/cm^{2})  effective water/cement ratio(by mass) {NonAirentrained Concrete}  effective water/cement ratio(by mass){Airentrained Concrete}  250  0.5  0.39  200  0.6  0.49  170  0.66  0.54 
Requirement for water / cement ratio and strength for special conditions 

Exposure Condition  Maximum w/c ratio  Minimum design strength (kg/cm^{2})  Fresh Water  0.5  250  Brackish or sea water  0.45  300  Kerbs, gutters or gardrails  0.45  300  In the presence of deicing chemicals  0.45  300  Deicing salts, brackish water, sea water  0.4  330 
Approximate requirement for mixing water and air content for different workabilities and nominal maximum sizes of aggregate (Nonair entrained) 

Workability or Air content  10  12.5  20  25  40  50  70  30  50  205  200  185  180  160  155  145  80  100  225  215  200  195  175  170  160  Approximate entrapped air content(%)  3  2.5  2  1.5  1  0.5  0.3 
Approximate requirement for mixing water and air content for different workabilities and nominal maximum sizes of aggregate (Air entrained) 

Workability or Air content  10  12.5  20  25  40  50  70  30  50  180  175  165  160  145  140  135  80  100  200  190  180  175  160  155  150  Average total air content(%)  6  5.5  5  4.5  4.5  4  3.5 
Dry bulk volume of coarse aggregate per unit volume of concrete 

Maximum size of aggregate  2.4  2.6  2.8  3.0  10  0.5  0.48  0.46  44  12.5  0.59  0.57  0.55  53  20  0.66  0.64  0.62  60  25  0.71  0.69  0.67  65  40  0.75  0.73  0.71  69  50  0.78  0.76  0.74  72  70  0.82  0.8  0.78  76 
First estimate of density (unit weight) of concrete 

Maximum size of aggregate  First estimate of density of concrete (kg/m^{3}){Nonair entrained}  First estimate of density of concrete (kg/m^{3}){Air entrained}  10  2285  2190  12.5  2315  2235  20  2355  2280  25  2375  2315  40  2420  2355  50  2445  2375  70  2465  2400 
Recommended Slumps for Various Types of Construction (mm) 

Concrete Construction  Slump Maximum  Slump Minimum  Reinforced foundation and footings  75  25  Plain footings, caissons, and substructure walls  75  25  Beams and reinforced walls  100  25  Building columns  75  25  Pavements and slabs  75  25  Mass concrete  50  25 
