Concrete

Formula

• 10% cement, 75% aggregate, 15% water [1]
• 150 kg/m3 of cement - with concrete at 4000 lb/cu yd [2] - was sufficient to get about 6000 psi concrete strength [3]. Does this mean abouut 8% of cement?
• 500 lb per yard of cement in concrete is recommended - read a thesis on it - [4]
• Lean or rich: 7-15% cement by volume -

• Lean concrete per california codes is 300 lb cement per yard of concrete, and is 700 PSI at 7 days. [5]
• Lean is used below foundations - and is 700 psi or 1100 psi [6]

Slab Requirements

• 2500 PSI concrete minimum for slab on grade in Oregon - [7] and Georgia [8]

Concrete Slump Testu

Measures inches of collapse, from 0-12", of a wad of concrete in a cone. 12" means it's complete water. 4" is very stiff.

Basics

• The Combination of Aggregate and Cement

Internal Links

• Reinforced Concrete

External Links

• The Wikipedia Page on Concrete