Why Do PSI And Slump Matter For Concrete Projects?

When it comes to concrete there are two factors that are critical to measure for every project: PSI and slump. Today we’re going to take a closer look at what these two factors are, and why they are so important to measure for any concrete project. 


PSI stands for pounds per square inch. The PSI measurement looks at how many pounds per square inch a surface can resist. Think of PSI as the total strength of a concrete. If you are building a concrete project like a driveway that is going to have thousands of pounds worth of vehicles driving on it, you are going to want to make sure that concrete has a high PSI rating. Conversely, something like a concrete wall will be just as effective with a lower PSI rating. 


There are several different ways to change the PSI rating for concrete, almost all of them have to do with what you put in the mixture and how long you allow the mixture to cure for. There are different mixes for different PSI ratings. Be sure to take the time to decide what type of weight your concrete project is going to need to hold when its finished, before you decide what type of concrete to purchase. 


Slump is a bit more complicated. Slump in the context of concrete work is a way to measure the consistency of a concrete mix. To determine slump, concrete is poured into a cone mold. Once that mold is removed, the number of inches the concrete slumps from the top is the slump measurement for that mix. 


Of course, different slump measurements are ideal for different types of work. Too little slump means there’s not enough water in the mixture. The right amount of slump will yield a concrete mixture that pours well and can be easily maneuvered in its space without sacrificing any durability of the final concrete product. Too much slump creates a concrete product that is measurably less durable than it should be. 


So, how much slump is too much or too little? A slump of 1-2 inches is not ideal because the low slump indicates that there is not an ample amount of water in the mixture. Usually, a slump of 4-5 inches is preferred. However, a slump of over 6 inches can be achieved with the right admixtures. Take the time to do your research and decide beforehand what amount of slump is right for your specific project. 


If all of this seems a bit confusing, don’t stress. It’s always a good idea to consult a concrete professional before embarking on any major concrete project to double check your work, or take it off your hands for the right price.


We suggest reaching out to Razorback Concrete for all of your concrete needs. Visit www.razorbackconcrete.com to learn more. 


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