The Wonderful The Wonderful World of ConcreteWorld of Concrete

Modern Materials Modern Materials

TechnologyTechnology

Mr. FordMr. Ford

BACKBONE OF CONSTRUCTION

• Concrete and Concrete products are the basis for most building and structural projects

• Some components are made on location and others are made elsewhere and brought to the job

The Concrete RecipeThe Concrete Recipe•Crush some limestone into a fine powder

•Heat to about 2700 degrees

•The powdered cement is super dry

•Mix it with clean sand or stones called an “Aggregate”

•Add water and mix

•The hardening is called “Hydration”

The Chemistry of Concreteor

How Does It Work?• The Limestone Powder is very small and very dry like

flour• When it mixes with the “Aggregate” and water it swells

around the small particles and reforms a rock-like substance holding the sand and stone in place

• The water causes chemical reaction to the powdered cement and it “Hydrates” into a solid substance

““Time to Pour the Batch”Time to Pour the Batch”

• Once mixed it Once mixed it must be must be constantly stirred constantly stirred so it does not so it does not hardenharden

• It is transported It is transported in special trucks in special trucks to the job-siteto the job-site

• It is then poured It is then poured into special into special containers called containers called “FORMS”“FORMS”

Shape It• The forms hold the

wet concrete in place while it hardens

• The surface can also be smooth while it is still in a mud-like state

• This work is done in a hurry before it hardens, “nobody takes a break at this time”

Later…………

• It may take 1 day or up to a week for the concrete to fully harden

• The forms are then removed leaving the concrete structure

Building With Blocks

• Concrete can be made in smaller parts and transported to the construction site

• The parts are stuck together using a wet concrete called “mortar”.It acts like glue and the blocks are assembled like a giant LEGO set

Structures and SurfacesStructures and Surfaces

• Concrete is used for Concrete is used for buildings, roads and buildings, roads and many projects that many projects that require strength and require strength and durabilitydurability

• It is available in It is available in most places and has most places and has a low costa low cost

Concrete has many uses

What would you make??