1. Introduction to Concrete and Masonry Ag III and IV

2. It’s pretty much everywhere. Work in groups of 3. In the next four minutes, list a different item made from concrete for each letter of the alphabet.  Example: A=Apple red fire hydrants

3. Today’s objectives Define concrete Name rules for making quality concrete List ingredients in concrete Identify properties of concrete

4. What is concrete? One of the most widely used building materials in the world No other building material in which the final product depends so much upon the user than concrete It’s everywhere  Share your lists!

5. It’s going to be around for a while Easy mixing process yields a product that weighs 150-160 lbs per cubic foot. Components of concrete: water, cement, and aggregate, are plentiful Requires little energy for production and use Qualities that give concrete appeal are going to still be important down the road:  Strength  Versatility  Durability  Fire resistance

6. Rules for making concrete Use proper ingredients Proportion ingredients correctly Accurately measure the ingredients Mix the ingredients thoroughly Follow proper finishing and curing methods

7. So what are the ingredients? (And how do they work?) Portland Cement Aggregate Water Portland and water forms a paste around each piece of aggregate Changes from a plastic state to a hardened state It’s not drying! It’s a chemical change. (Think release of heat.)

8. Properties of “plastic” concrete Consistency (or slump)- wetness or dryness of the mix Uniformity- thorough mixing of ingredients Workability- ease with which it can be placed and consolidated

9. Properties of hardened concrete Each person is receiving an index card. Match the correct word with the definition. Take your seats, so I’ll know you’re done.

10. Today’s objectives Identify properties of concrete Name rules for making quality concrete List ingredients in concrete Discuss the difference between cement and concrete