Understanding Slump

Have you ever observed how workers construct roads, or how they build flooring inside a home or apartment unit? Well, for the uninformed, the material commonly used for road surfaces and interior flooring is made up of concrete, which is generally composed of a mix of water, sand, cement and gravel. More advanced concrete mixes include stuff like chemical additives, plastics and fibers. The mixture proportion determines the properties of concrete (and this includes something called the “slump”). Read on to further understand what slump is all about.

What Does Slump Mean?

When I talk about slump, I am absolutely not referring to a sudden, severe or prolonged fall in stock prices on Wall Street. I am also not talking about an economic recession. Instead, I’m referring to something that deals with the quality of concrete.

According to seasoned concrete suppliers in my city, slump is defined as the measurement of the consistency or durability of concrete. In much simpler terms, this measures how easy or hard it is to push, mold and smooth out concrete.

Concrete’s slump rating denotes what construction application the concrete is appropriate for, as the higher the slump, the more “workable” would the concrete be. If the slump is low, then the concrete will not easily shape. And, if the slump is so high, then the concrete may become unusable because the gravel, sand and cement may settle out of the mixture.

How a Concrete Slump Test is Done

Once the concrete delivery truck arrives at your project site, the workers are not going to start pouring it yet, but what they’ll instead do is perform a series of tests, and one of that includes a concrete slump test.

According to civil engineering experts, a concrete slump test is often utilized to find out the appropriate water content in a batch of premixed concrete . Slump also determiens the distance (which is measured in inches) the concrete settles after removing a tool called the slump cone.

A concrete batch or mix that shows a high slump indicates that the batch has too much water in it, and would possibly be weak once it is fully cure.  The ideal concrete mix would be something that’s not too soft or stiff.

If contractors are working in very hot or very dry weather conditions, of if the mold has more intricate or complex shapes, then they may want to have a slightly wetter mix. Perhaps all contractors will tell you that if there’s more water in the concrete mix, the higher will be the risk of cracking. Mixes that are too dry will also be quite tough to pour and vibrate.

Doing a slump test gives contractors a good idea of what the proper mix should feel like. If you’re longing to do things the DIY way, perhaps you should get some training and guidance from professional contractors or construction workers, so that you’ll slowly gain the skills required to do a proper concrete slump test!

Finally, here’s a word of caution from construction experts – never use slump level to compare the quality of one concrete mixture to another. Instead, one should only utilize it to compare the quality of various batches of the same mixture!