Hyde Concrete FAQ:

1. What is Concrete?
   Concrete by definition is the mixture of Cement, Water, Aggregate (e.g., Stone) and Sand.
2. What is the difference between concrete and cement?
   Cement is an ingredient of concrete, it serves as the binding agent of the mixture
3. What is a ‘modified cement’?
   This is a cement that has been modified with particular chemicals (usually polymers and acrylics) to give it particular characteristics. For our purposes, this usually means a product that can be applied in a very thin layer, yet remain very durable.
4. What causes concrete to crack?
   Concrete can crack for a variety of reasons. One of the more common cracks are ‘shrinkage cracks’ that occur while the concrete is curing. During the curing process of concrete, moisture is leaving the concrete and causing it to shrink (think of dried mud in the sun). Sometimes, this can create enough stress in the concrete to crack. We try to control this by no being excessive with the quantity of water and by proper placement of control joints. A second reason is heaving and/or improper support under a slab. Either way, the ground under the concrete has/is moving and causes the concrete to flex and crack. We try to limit this by ensuring the ground receiving the concrete is properly preppared.
5. How is concrete reinforced and why?
   Concrete has terrific compressive strength, but like glass, it does not have great tensile strength. This means is has the potential to hold up great weight, but can’t flex much or it will crack. We insert either metal bars (e.g., rebar or welded wire mesh) or fibers to give concrete a stronger capacity to flex and stretch.
6. How does water affect fresh concrete?
   If water hits concrete while it’s still curing, it could partially weaken the surface. However, once the concrete is finished, water is good because it retards the evaporation process and allows the concret to cure at a slower rate, thus resulting in a stronger concrete.
7. What is the white powder I see on new concrete sometimes?
   That is called efflorescence and it is a natural process in concrete. It is the minerals and salts escaping from the curing concrete. It will wear off with time or can be washed off after a few weeks.
8. How does concrete cure?
   Concrete cures through a process called ‘Hydration’. That is a chemical process the cement goes through when it reacts with moisture and becomes hard.
9. Why does concrete have stones and sand in it?
   The stones and sand serve as filler. Cement is relatively expensive and not as tough as stone, so they get combined to create a stronger product.
10. Can it be to hot or to cold to place concrete?
    Temperature affects the curing of concrete (slower in cold, faster in warm) and as finishers we are mostly concerned with how it will affect our efforts. Generally in our area, it is rarely too extreme to pour.
11. Are there different types of cement?
    Yes, there are 5 types. Called Type I, Type II and so on. There is also White Portland Cement. Each type has different characteristics, but they all serve the same purpose.
12. If you have any other questions that you don’t see here – please feel free to send an e-mail and we will answer your questions to the best of our abilities!