Concrete "Approved Mix Designs"

Many contractors will look at their approved plans to find out what the required concrete PSI is, and then order that PSI concrete from any supplier. But for some jobs, the engineer may specify a certain "approved mix design".

 An approved mix design is basically a letter submitted to the project engineer from the ready mix concrete company that is supplying the job which states each specific amount of each type of material is in that mix #. It will list the material measured in pounds, gallons, or ounces, the required slump of the concrete, and much more.

 Specfically, some of the things that need to be listed include how many pounds of sand, cement, water, aggregate (and what size), or any admixtures that may need be to be added to the mix depending on the jobsite's conditions, ie: a water reducing admixture, fly ash, added air content and more. (The list of requirements to be shown on a mix design  can get pretty technical)

 Most concrete companies will supply these mix design letters so that they can be submitted to the engineer and returned to you with his stamped approval on it.

 If an approved mix design is required for your jobsite a Deputy Inspector will need to verify that each load of concrete has a ticket that shows that mix design # on it.

 Some of the jobs that could require an approved concrete mix design are larger projects, jobs that have unique situations such as freezing / thawing conditons, jobs where high psi concrete is required, or projects where soil conditions require additional admixtures or different types of cement, but there can be many, many other reasons for the project engineer to require a specific mix design to be approved.

 Most of the time, if a specific mix design is required for your project, the City Inspector will ask to see it before they give you the go ahead to pour your concrete. But, always check your plans carefully, and if you are not sure, it might be a good idea to give your project engineer a call before ordering your next load of concrete.

If you have any questions regarding a Special Inspection, or a Deputy Inspector for Concrete, Epoxy, Masonry, Nailing, Shotcrete, and more, feel free to call anytime!

(805) 857-7908