How long should you mix concrete in a mixer?

Mix the concrete for about 3-5 minutes, until a uniform, workable consistency is achieved. If additional water is needed, add small amounts of water sparingly.

What is the minimum mixing time for concrete?

Mixing Time of concrete mixers Since concrete mixers rotate at a minimum rate of 15 rpm, the mixing time required to produce 1 batch of concrete is 2 minutes.

How many revolutions does it take to mix concrete?

Concrete can be mixed in the yard. This is the most common way to mix concrete produced at a transit mix plant. The drum is turned at high speed for about 70 revolutions, at 12-18 revolutions per minute, before driving to the construction site.

How fast should a concrete mixer spin?

Mixing should be done in the range of mixing speed recommended by the mixer manufacturer, generally in the order of 12 to 18 rpm.

What is the proper mix for concrete?

Four-two-one and the Seven Part Mix Ratio The safest bet for any concrete mix is four-two-one: four parts crushed rock; two parts sand; and one part cement. The four-two-one mix, obviously, has seven parts. Conveniently, when mixing concrete, the ratio can be mixed on any range of scales.

How much concrete is in a small mixer?

A 6-cubic-foot cement mixer holds 6 cubic feet of material if positioned upright and filled to the brim. The maximum working capacity of the mixer falls far short of that. Six-cubic-foot mixers can mix only 3.5 cubic feet of material or less. Mixing less than the maximum load puts less strain on the mixer’s motor.

What affects mixing time?

Factors that affect mixing time Mixer speed: the higher the speed, the more blending and work is applied to the system, and the shorter the mix time needed to obtain the desired result.

How does the time of mixing affect the strength of concrete?

In one test series slump dropped from 9.0 inches after 1 minute of mixing, to 8.4 inches after 5 minutes, to 6.4 inches after 30 minutes and to 2.6 inches after 60 minutes. There were also marked increases in compressive strength with increased mixing time.

How long is concrete workable after mixing?

With basic concrete mix, you can usually walk on the slab about 24 hours after finishing the surface.