Concrete FAQs

Do I want concrete or cement?

This question is similar to; do I want a cookie or flour? Cement is one of the components that make up concrete; it is the product which holds together the sand and gravel once water has been added to the mix. Portland Cement, as it is known, is one of the basic ingredients in many construction products, from tile grout to concrete block.

What is a concrete mix?

The concrete mixes used in the early days were commonly 1-3-5 or 1-2-3, referring to the proportion of cement to be blended with those of sand and gravel. A concrete company’s “MIXES” are the recipes it uses to produce the wide ranging variety of concrete its customers require. Salmon Bay currently has 1100 various mixes which we produce.

What does sack 5 sack mix mean?

1-3-5 would be; 1: Cement, 3: Sand and 5: Gravel. This would approximate today’s 5 Sack mix (5 sacks of Cement per cubic yard of Concrete).

How is concrete strength measured?

Normal mixes of 5 to 6 sack concrete regularly produce a compressive strength of between 2000-4000 PSI (pounds per square inch) at 28 days.

How long does it take for concrete to get hard?

Concrete will take an initial set in generally 2-3 hours depending upon the air temperature, amount and type of cement in the mix and several other environmental conditions. We recommend that you stay off freshly placed concrete, as much as possible, during the first 3 days….after 7 days light vehicle traffic is possible. Concrete has its most rapid strength gain over the first 7 days and is considered to be cured and near full strength in 28 days although the process of strength gain can virtually go on for years.

What is a concrete Admix?

Concrete admixtures are naturally occurring or processed chemicals which are “added” to concrete, while in a plastic state, to modify its properties. These modifications are made to enhance the performance of standard concrete mixes or change the normal working properties of typical concrete and are a benefit to virtually all the parties involved in a concrete placement.

What is Concrete’s Slump?

Slump is the measurement (in inches) used to describe the stiffness or fluidity of Concrete. The lower the number the stiffer the concrete mix, the higher the number the more fluid the mix will be. It is best to keep the slump as low as possible, but still workable enough for proper placement. Most Concrete is delivered with a 4” slump.

What is the difference between Curing Compounds and Sealers?

Curing Compounds are used immediately after the concrete is placed, when it is beginning to “cure”. Curing compounds function by slowing the dissipation of moisture from fresh concrete. This allows for better hydration of the cement particles, resulting in higher strength and improved durability. Sealers are typically applied to hardened (fully cured) concrete and serve to protect the concrete from moisture and various stains. Sealers are either penetrating or film forming. Penetrating sealers typically last longer than film forming, because they become part of concrete. A surface sealer usually creates a sheen or glossy finish and will generally clean up easier, because it is a less porous surface. Combination “Cure and Seal” products are also available

Do you have a SDS for Concrete?

Yes! Please click this link to find out more.

Will my new concrete crack?

The old adage that “concrete will be gray, get hard and crack” is essentially true. Concrete cracks for a number of reasons including poor finishing techniques, improper layout, wrong mix for the application, rapid moisture loss, stresses of nature and the natural process of drying and shrinking. Cracking can be minimized, but not eliminated, with proper joint layout, reinforcement, good curing process and experienced workmanship.

Can you deliver Pervious Concrete?

Yes we can produce pervious concrete. Previous concrete is a porous mix that allows water to drain into the Concrete and back into the ground through an underlying drainage media. It must be place by an experienced contractor, properly protected during the construction process and kept clean in order to perform as designed.

What about placing concrete in cold weather?

Cold weather and frosty or frozen ground can increase set times and adversely effect the finishability of concrete. This can lead to the concrete freezing prior to setting, which may result in severe cracking and or scaling of the surface.
Here are some necessary precautions to avoid the problems of placing and finishing concrete in cold weather:

  • Increase cement content for cold weather.
  • Use hot water to help raise the temperature of the mix.
  • Use Calcium Chloride to accelerate set times.
  • Use non-chloride accelerators such as MasterSet AC-534.
  • Try to keep the area enclosed and heated if possible.
  • Don’t place concrete late in the day if temperatures are to drop.
  • Use curing blankets or poly-film to help hold the heat in.
  • Protect your forms from freezing the night before by covering with blankets.

What about placing concrete in hot weather?

Hot weather and windy conditions can produce a rapid rate of evaporation, and accelerated setting times, this can lead to increased water demand which will lower potential strengths and can induce plastic shrinkage and or drying shrinkage cracking.
Here are some necessary precautions to avoid the problems of placing and finishing concrete in hot weather:

  • Minimize cement content for needed P.S.I.
  • Use Fly Ash to help lower heat caused by hydration.
  • Use retarding admixtures such as, MasterSet R100 or Delvo
  • Use water to pre-wet forms, sub-grade and steel.
  • Add personnel to handle the concrete.
  • Schedule pours earlier in the day. Try to plan for shade if possible.
  • Moist cure the concrete with water as soon as finishing is done.
  • Use poly film or other suitable material to reduce evaporation.
  • Use curing compounds, such as L M Cure & Seal.
  • Use evaporation control products, such as E-con

Is it possible to color concrete?

Yes it certainly is. Concrete can be colored in a number of ways; from integrally coloring via natural oxides introduced into the mix at the Ready-Mix plant, coloring and stamping during placement, to coloring the surface with a variety of different concrete staining products after the concrete has cured. We have all these options available and our sales staff is very experienced in discussing these choices with our customers. For more information, view our “Colored Concrete Policy”.

Can you provide lightweight concrete?

Sorry, but we are not in the light weight concrete business. The NW does not have an economical source of quality light weight aggregate, which is the primary ingredient of a good lightweight mix.

Do you pump concrete?

We supply jobs with a good pump-able mix, but the pump trucks are supplied by others.

What is the smallest load of concrete you can deliver?

Our minimum delivery of concrete is 1 ½ cubic yards or 40 cubic feet.

How do I place an order?

The most important piece of information is….where geographically is the project located? Concrete plants generally are situated to serve a particular regional area. Since we are located in Ballard, we are not able to properly service jobs in Enumclaw or Everett, for example. And as we all know….Concrete is going to eventually get hard…. we just don’t want it to get hard in our trucks. Secondly, know the 3 dimensions of the project you will be pouring. Concrete is calculated in cubic feet, which is the length, width and depth all multiplied together (see our concrete calculator). Next, what are you making and when were you planning on having the delivery. This information helps us determine the proper mix to provide you with and develop a delivery schedule….we usually like 48 hours notice (we do not deliver on weekends or legal holidays). Our Dispatching and Sales crew now have enough general information in order to proceed with taking your order and finalizing a few other important details. For more information, view our “Delivery Scheduling & Services”.

Will your trucks drive onto my site to make a delivery?

Our drivers will do the best they can to accommodate your needs. However, once they leave the street and cross the curb line, the homeowner or contractor is responsible for any subsequent damages that a large, heavy vehicle, with limited visibility may cause the property.