We will make and test concrete with plasticizer and fiber

The construction market offers a wide variety of plasticizers that make the solution more plastic with less water included. In theory, their use should contribute to less shrinkage and increased strength, but is this really so? The question also arises as to whether fiber reinforcement can change the characteristics of concrete, since it does not inspire confidence against conventional steel reinforcement or mesh.

Materials:

cement;
sand;
gravel;
water;
plasticizer;
fiber.

Testing of ordinary concrete improved with a plasticizer, as well as with fiber and plasticizer

For the experiment, thick concrete grade M500 is mixed.

A sample is taken from a concrete mixer into a plastic bucket. Due to its thickness, this solution does not smooth out well.

To obtain the second sample, a plasticizer is added to ordinary concrete in a mixer according to the instructions. The solution immediately becomes plastic. The sample is taken into the second bucket. This concrete flows easily.

For the third sample, fiberglass is added to the concrete mixer. After mixing, the concrete is also taken into an empty bucket.

After the samples had set in a shaded place, testing began.

Ordinary concrete has visible pores and is quite rough. When thrown onto a metal sheet from a height of 2 m, it breaks after a couple of falls. When struck by a hammer, the sample easily crumbles.

Concrete with plasticizer looks glossy and has fewer pores, but a thin crack appears on the sample.

In terms of strength, it is worse than ordinary concrete. The sample breaks when thrown from a height of 2 m the first time. It also crumbles easily with a sledgehammer.

The sample with plasticizer and fiber is also glossy on top.

To break it, I had to throw it from a height of 2 m a dozen times.

Cracks appear, but the pieces are held together by fiber.

This type of concrete can withstand blows from a sledgehammer.

From this we can conclude that the plasticizer reduces strength, but makes it easier to work with concrete, making its surface smooth and glossy. The only thing that really helps is adding fiber. It makes concrete almost indestructible. It is best to use only it without plasticizer.