CEB Prototype IV Calculations
Basics
- Recommended pressing force depends on brick area
- Recommended force is ______________ for 2", 4", 6" thick brick
- AECT says - 1070, new mexico, 800, Colorado, 970 lbs in Texas. Changes per soil and moisture
- Powell and Sons says -1200 psi on the brick to press 4" tall bricks
Powell and Sons
pi r squared for the cylinder pressure at 3000 psi yields
3.14 * 2.5^2 * 3000 = 58875 lb
According to Powell and Sons, we need 1200 psi on the brick to press 4" tall bricks - 8x12 bricks
or 1200*12*8 = 115,000 lb
Former work - we made 6x12 bricks - or 86,000 lb
115kips required from cylinder. Cylinder provides 3ksi according to these rules. We need 115/3 = 38si of cylinder which yields a 7in cylinder. Standards are 5,6 and 8. An 8" bore is 3x the price of a 6" bore. ChiefWHP makes a cylinder with a clean shaft - 2.25" exposed [1]. The load on this one is 113 kips. Dan Powell also said their calculations typically have 100% safety. Because of this I think the 6" bore will do the trick.
AECT
Lets assume 1070 lbs per inch of brick
1070*12*8 = 102720 lb from cylinder yields 6.6" diameter cylinder.
Conclusion
We will continue to press 6x12 bricks and now use a 6" cylinder.
