Formwork for Concrete Structures by R.L.Peurifoy and G.D- By EasyEngineering.net

Downloaded From : www.EasyEngineering.net
vi
Contents
Relationship between Rate of Fill, Temperature,
and Pressure for Wall Forms . . . . . . . . . . . . . . . . . 28
Lateral Pressure of Concrete on Column Forms . . . 31
Example 3-4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Example 3-5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Example 3-6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Relationship between Rate of Fill, Temperature,
and Pressure for Column Forms . . . . . . . . . . . . . . 33
Graphical Illustration of Pressure Equations for
Walls and Columns . . . . . . . . . . . . . . . . . . . . . . . . . 33
Effect of Weight of Concrete on Pressure . . . . . . . . . 36
Vertical Loads on Forms . . . . . . . . . . . . . . . . . . . . . . . 36
Example 3-7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Example 3-8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Example 3-9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Placement and Consolidation of Freshly Placed
Concrete . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Wind Loads on Formwork Systems . . . . . . . . . . . . . . 39
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
ww.EasyEngineering.n
4 Properties of Form Material . . . . . . . . . . . . . . . . . . . 41
General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Properties of Lumber . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Allowable Stresses of Lumber . . . . . . . . . . . . . . . . . . 44
Adjustment Factor C D
for Load-Duration . . . . . . . . . 46
Adjustment Factors C M
for Moisture Content . . . . . 46
Adjustment Factor C L
for Beam Stability . . . . . . . . . 51
Adjustment Factor C P
for Column Stability . . . . . . . 51
Adjustment Factors C fu
for Flat Use . . . . . . . . . . . . . . 52
Adjustment Factors C b
for Bearing Area . . . . . . . . . . . 52
Application of Adjustment Factors . . . . . . . . . . . . . . 53
Example 4-1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Example 4-2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Plywood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Allowable Stresses for Plywood . . . . . . . . . . . . . . . . . 55
Plyform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
High-Density Overlaid Plyform . . . . . . . . . . . . . . . . . 60
Equations for Determining the Allowable
Pressure on Plyform . . . . . . . . . . . . . . . . . . . . . . . . 60
Allowable Pressure Based on Fiber Stress in
Bending . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Allowable Pressure Based on Bending Deflection . . . . 63
Allowable Pressure Based on Shear Stress . . . . . . . . 63
Downloaded From : www.EasyEngineering.net