Concrete 100: parameters, brands, composition, application

What is concrete grade 100? In general, what is this parameter - concrete grade? What components and in what proportion are included in the material of interest to us? What is it used for and how is it processed after curing? Let's figure it out.

Parameters and marks

Let's start with the general concepts.

The main document that regulates the production of ready-mixed concretes and dry mixes is the standard GOST 7473-94, in which, among other things, there is a list of the main properties of the material. So, according to what parameters are concrete mixes classified?

Strength

The grade of concrete in terms of strength corresponds to the maximum compressive force that a monolith that has gained full grade strength can withstand without destruction. The mark corresponds to the pressure in kilograms per square centimeter of surface.

The most durable is concrete M 1000, capable, as follows from the mark of strength, to withstand pressure per ton per square centimeter.

A synonymous concept is a class of strength. The only difference is that the class corresponds to the maximum non-destructive pressure, expressed not in kgf / cm2, but in MPa (megapascals). So, concrete M 100 and B 7.5 is one and the same material.

We give a table of correspondences of brands and class.

Please note: the strength mark is in no way connected with the ability of the monolith to resist tensile or flexural loads. Actually, in reinforced concrete, the corresponding loads are perceived by reinforcement.

Frost resistance

What is a frost resistance mark?

Так называется количество циклов заморозки и оттаивания, которое материал может гарантированно перенести без снижения прочности более чем на 5% по сравнению с не подвергавшимися замораживанию образцами аналогичного возраста. Brand по морозостойкости традиционно обозначается буквой F (от англоязычного «frost»). Например, бетон f100 - это материал, способный пережить не менее 100 циклов.

The main factor affecting frost resistance is the number of open pores, the crystallization of water in which, in fact, leads to gradual destruction. The number of pores also affects the compressive strength: the smaller they are, the stronger the material. It is easy to guess that, in general, strength and frost resistance are interrelated: the improvement of one parameter leads to the improvement of the second.

Other parameters

In addition to these parameters, concretes are classified by two more:

1. Water resistant - the ability of the material to resist the penetration of water through its pores.
2. Workability - the mobility of the mixture, its ability to fill the form without additional effects.

We deliberately do not focus on these characteristics - simply because the corresponding brands in no case fall short of 100.

Composition

Heavy concrete, as a rule, includes a binder - Portland cement - and aggregates: sand and crushed stone. What are the proportions for concrete grade 100 and other grades of strength?

Pay attention: the given values ​​are relevant only and exclusively for heavy concrete. Aerated concrete 100, for example, will have a completely different composition: there is no rubble in it, and the drop in strength due to the porous structure is compensated by an increased amount of Portland cement.

Application

When mixing mortars, the main factor determining the price of a cubic meter is the percentage of cement. Other components are much cheaper.

Where can be used extremely cheap concrete mix of low strength?

• For pouring rough concrete screeds and cushions for foundations. In this case, a layer with limited strength between the ground and the main monolith performs several functions at once: it distributes the load during advances and subsidence of the soil, waterproofs the reinforcement and prevents filtration of the cement milk into the soil. As a rule, the thickness of the pillow is limited to 100 millimeters.

• For concreting fences, curbs, pillars.

If the concreting of the curbs and pillars does not require any comments, then the technology of laying a concrete pad under the foundation is probably better to make out in more detail.

1. The base is leveled.
2. Then the surface is filled with sand or gravel. Bedding thickness - 15-20 cm.
3. Backing ram. With a small footprint, it is easy to do the job yourself; the simplest tamper is made of a piece of a bar or log with an ostruganny handle nailed to it.

Tip: sand for shrinking is enough to pour plenty of water.

1. Concrete is laid out on the surface of the bedding and leveled. Splicing is desirable but not necessary.

Treatment

It comes down mainly to dismantling. Cases when it is necessary to drill holes or openings in the roughing screed are quite rare.

Instructions for the production of works, in general, is quite common:

• Used for dismantling crowbars and jackhammers.
• Small holes are drilled with a perforator (auger or crown); openings of a considerable size are cut out by a grinder with cutting circles on the stone.
• In those cases when ideally smooth edges of the hole are needed, preferably diamond drilling of holes in concrete. It does not require the use of a shock mode and, accordingly, does not lead to the appearance of chipping.

In addition: drilling with a diamond crown, as well as cutting reinforced concrete with diamond circles, allows you to pass the rebar without a tool change.

Conclusion

We hope that the information presented in the article will be useful to the reader. As usual, additional materials can be studied by viewing the video in this article. Successes in construction!