Concrete By John Templeton

What is concrete used for? _________________ Driveways _________________

Advantages of Using Concrete: Fire Proof _________________ Durable and Termite and Rodent _________________ Proof Watertight Sanitary Economical Storm Resistant

Agricultural Uses of Concrete: ________________ Porches Walls and Foundations Steps Small Bridges Setting Posts Walks Water Troughs

Quality Concrete Hardened Concrete should have the following qualities: –Durability: refers to resistance to chemical actions, freezing, and thawing. –___________________________________________________ __________________________________________________. –Watertightness: the ability to prevent water passage through the mass. –Wear resistance: the ability of hardened concrete to resist abrasive action of vehicles, feet, and flowing water.

Quality Concrete Fresh concrete should have the following qualities: –Consistency: refers to the “wetness” and “dryness” of the mix. –__________________________________________ __________________________________________ –Workability: refers to the ease with which concrete can be placed and shaped.

Concrete Ingredients PORTLAND CEMENT –____________________________________ –This is a carefully proportioned and specially processed combination of lime, silica, iron oxide, and alumina. –It is usually manufactured from limestone mixed with shale, clay, or marl.

Concrete Ingredients PORTLAND CEMENT –Properly proportioned raw materials are pulverized and fed into kilns where they are heated to a temperature of 2,700°F and main tained at that temperature for a specific time. –There are five types of Portland cement covered under “____________________________________ _________________________________________.”

Concrete Ingredients AGGREGATES –The material combined wi th cement and water to make concrete is called aggregate. Aggregate makes up 60 to 80 percent of concrete volume. –______________________ _____________________ reduces the shrinking tendencies of the cement, and is used as an economical filler.

Concrete Ingredients AGGREGATES –Aggregates are divid ed into fine (usually consisting of sand) and coarse categories. –__________________ _________________, the coarse aggregate consists of gravel or crushed stone up to 1 1/2 inches in size.

Concrete Ingredients AGGREGATES (SAND) –Finer aggregates such as sand fill-in between the larger partials (gravel). –____________________________________ ____________________________________.

Mixing Ratio 1 ______________________ 2 parts Fine Aggregate 3 Parts Coarse Aggregate

Pouring Mixture

Preparation Concrete may be mixed –In a wheelbarrow using a shovel or –Shoveled into a small electric or gasoline powered mixer __________________________________

Digging In many cases the area where concrete is to be poured or placed must be dug out. –Example: Driveways and sidewalks are generally one inch above the ground level when finished. __________________________________

Forms Concrete form: Frame or mold that holds new concrete in shape until it has set or hardened. _______________________________ _______________________________

Reinforcing Bars and Wire If heavy equipment will drive over concrete or freezing and thawing will be a problem, concrete should be reinforced Reinforcing bars: Steel bars with ridges that bond with the concrete –____________________________________ ____________________________________

Moving and Spreading Concrete __________________________________ ___________________________: –Shovels, –Spades, –Rakes, and –Concrete drags

Floating Pushing the rocks down and bringing sand- cement paste to the surface and beginning the smoothing process ____________________________________ ____________________________________ ____________________________________ ( Picture Courtesy, Interstate Publishers, Inc.)

Floating Darby: ____________________________ ___________________________________ Bull float: 36 or 42 inch float with long round handle used to reach areas away from the edge

Calculating Material Needed Example: –Your are going to pour a concrete slab for a small pump house the slab will need to be: 8’X6’X4” –8 feet wide –6 feet long –4 inches thick How much concrete will be needed?

Calculations