The Exciting world of Construction - Concrete Composition and Failures

Welcome back to The Exciting World of Construction. Concrete Composition and Failures.

Lesson Two! You've heard the saying "...As boring as watching paint dry."

But is it really?

Is it boring to watch the color change and see the lines blend to display your beautiful new color and even coats? If watching paint dry is your thing, imagine the "chill" of watching concrete cure.

First things first, what exactly is concrete? Follow us on quick journey through the world of concrete composition...

• Concrete is a general term for a mixture of fine aggregate (Sand), Coarse aggregate (Stone), Portland cement, and water. A Chemical reaction occurs as these are mixed which changes the mixture into a uniform composite. This transformation is called curing and the curing process, though initially rapid, takes nearly a month to be fully complete.

• Concrete has little tensile or bending strength.  Steel rebar is added as reinforcement. Cracks are not uncommon especially with flatwork such as sidewalks and driveways but do not necessarily indicate a “failure” of the system.

• Concrete has high compaction strength; thus, very heavy buildings are built on top of them. Modifying the combination of aggregates, cement, and water, plus an alphabet soup of other additives can improve the compressive strength.

Now, let's see what failures you should look for in your concrete: 

• Spalling – When the surface of concrete “pops” off.

Spalling - Photo Credit: https: //gsgdistribution.com/spalling-concrete-repair/

• Efflorescence – When moisture moves through the concrete, evaporates off the surface, and leaves trace amounts of visible minerals (Typically white in color) on the surface.

  

  Efflorescence - Photo Credit: https://www.concreteconstruction.net

  
  

• Rust Jacking – When moisture enters the concrete, rusts the rebar, and then the expanding rust forces spalling or cracking of the concrete.

  

  Rust Jacking - Photo Credit: UPSI Project

• Stress Cracking – When movement (Often from expansive soil or seismic events) shears the concrete.

  
  

  

  Stress Cracking - Photo Credit: https://concretesupplyco.com/6-concrete-cracks/

  ...Actually, this IS a failure of the system. You should probably call us soon!

If you see any of this damage happening to your concrete, you know who to call! We are happy to give you a consultation to determine the best way to solve your concrete concerns.