An example of the design of a concrete care journal. When you need a concrete journal

Concrete care - methods, methods and documentation

The strength of concrete and reinforced concrete structures depends not only on the quality of the mixture and correct execution installation work, but also on the conditions in which it hardened. We will tell you how to care for concrete by touching on the issue of documentation. Additionally, consider a concrete care log for an example of filling.

What processes occur during concrete hardening

During hardening, the water that was used for mixing reacts with the substances that make up the cement. As a result, a durable cement stone is formed. This process is quite long, the material gains brand strength after 28 days, but hardening does not end there, some reactions with a sufficient amount of moisture can take much longer. But since this indicator is taken in all calculations, it is important to ensure optimal hardening conditions during this period.

What is important for hardening to occur correctly

Concrete maintenance must be able to withstand the following conditions:

• provide a sufficient amount of moisture;
• protect the product from mechanical damage;
• ensure the optimum temperature;
• prevent water from freezing, as ice crystals, expanding, violate the structure of the cement stone.

What regulates the care of concrete after pouring

On this moment in the construction industry, these works are regulated by the section "curing and maintenance of concrete" SNiP.03.01-87 "Bearing and enclosing structures". It is small, three points, in which it is determined that:

• optimal temperature and humidity conditions and protection from atmospheric precipitation and moisture loss must be observed (a concrete care log helps to control these conditions);
• maintenance of concrete should take place according to the work plan (PPR);
• the strength (1.5 MPa) is determined at which it is allowed to move people and install further tiers of formwork on the surface.

Conclusion - it is very important to have a properly developed PPR, which contains the necessary measures.

Care measures

We list the most common measures for maintaining concrete structures:

• Water escapes primarily through surfaces, so it is necessary to shelter them from wind and sun exposure. For this, a film or a damp cloth, tarpaulin is used. There are also special solutions to protect against drying out. As a last resort, you can cover it with shavings or sawdust, which also needs to be moistened with sand. The shelter additionally provides protection of its surface from damage by atmospheric precipitation (rain, hail).
• If concreting is carried out in the ground, then waterproofing must be provided to protect against water filtration from the solution into the soil.
• To achieve optimum moisture content, the concrete must be constantly moistened (most of the advice on how to care for concrete after pouring only applies to this operation). The best option (this is how the cubes harden for testing) after two to three days generally place the structure in water. But for large structures this is impossible to implement. Usually, the surfaces are simply shed under a slight pressure, so as not to damage or moisten the material with which they are covered.

Winter concreting measures

It is not advisable to carry out concrete work in the summer, but this does not always work out. Concreting in cold weather requires the use of special technologies - for example, antifreeze additives are introduced into the mixture to reduce the temperature at which ice crystals are formed. Concrete maintenance in summer is different from such work in winter, when special measures are taken to ensure proper hardening. Here are some examples of caring for poured concrete in winter.

• The formwork is insulated. Open surfaces are not only covered to reduce evaporation and protect from precipitation and the sun, but are additionally insulated.
• Structures are heated in several ways - with external electric heaters or heat exchangers, with the help of infrared lamps or burners, or they are heated by passing current from special transformers through a reinforcing mesh.
• Only hot water is used for humidification.
• If possible, a shelter or tent is installed around the structure, the inner volume of which is heated with the help of air heat generators (guns) or in another way. Steam supply is also possible, then the surface will be moistened at the same time.

What documentation is kept (concrete care log, fill sample)

By doing construction works, on the quality of which the reliability of the structure depends, each stage is necessarily documented. In our case, this is a magazine for the care of concrete, you can freely download it online. It is stitched and sealed, and each record in it is confirmed by signatures. Let's consider an example of filling by columns.

1. this is the name of the structure;
2. the volume of the laid mixture;
3. surface modulus - the ratio of the surface area of \u200b\u200bthe structure to its volume;
4. aging methods - normal heating, thermos method, etc .;
5. Date and time of the start of installation;
6. date and time of the beginning of aging;
7. aging period (not in days, but in hours);
8. outside air temperature;
9. average holding temperature;
10. date and time of temperature measurements at several points (wells) in volume;
11. the penultimate column: signature of the person who took the measurement;
12. at the end, a column is left for comments.

A correctly completed concrete care log allows in most cases to determine the cause of defects in finished structures - whether they are caused by poor-quality materials, improper concreting, or formed during the hardening process. Therefore, its maintenance is no less important than the execution of acts hidden works and the availability of quality certificates for the components of the mixture.

Questions and answers on the topic

No questions have been asked about the material yet, you have the opportunity to do it first

A concrete log should be kept at each construction site. It is necessary to register in the journal every shift the date and time of concrete placement, the method of concrete care, the consumption and time of applying vapor-moisture-proof and thermal insulation materials to concrete, the state of the weather and the duration of concrete care, as well as the time of opening movement on the coating.
When concreting critical structures, the composition of measures for the care of concrete, the procedure and timing of work are established in or given in the instructions of construction laboratories approved by the chief engineer of construction. All concrete care measures are recorded in the concrete care log

Graphs concrete care log:
1. The name of the concreted part of the structure
2. Volume of concrete
3. Surface modulus m2 / m3
4. Concrete curing method
5-6. Date and time of completion of concrete placement - month and day - hours
7-8. Concrete curing starts - month, day and hour - concrete temperature
9. Duration of holding per hour
10. Outdoor temperature
11.Average holding temperature
12. Date of temperature measurement: month, day, hour
13. temperature wells. Concrete temperature
14. Signature of the laboratory assistant during control and measurement
15. Note
To obtain concrete of the required strength and density, surface quality, as well as to achieve all these indicators in a timely manner, it is necessary to organize proper care behind concrete: keep it wet, protect it from shocks, shocks and vibrations at the initial setting and hardening times, and prevent sudden temperature changes. Maintenance-free concrete even with high quality source materials and adherence to the technology for preparing and laying the mixture can negate all efforts and lead to the receipt of a defective, unusable concrete product or structure.
The most favorable conditions for concrete gaining strength or concrete resistance are humidity close to 100%, and temperature environment - 18 ... 20 ° C.
To protect concrete from drying out at low ambient temperatures in the case of production of walls, purlins, girders or other structures with a small open surface area in wooden formwork, no additional measuresas the concrete will suck out the water absorbed by the wood during its formation.
Open surfaces of freshly laid concrete in hot and dry weather, 1 ... 4 hours after laying, are covered with a moisture-absorbing material (burlap, sand, sawdust, mineral wool slabs etc.) and watered with water.
Depending on the concrete hardening conditions, watering is carried out in such a way that the surface is always wet.
In hot weather, water also wooden formwork... When removing the formwork in early dates watering must be continued, especially abundantly watering the stripped vertical surfaces. Estimated time frame, during which it is necessary to keep the concrete in a wet state, depend on the type of cement, design features of the manufactured product and are 3 ... 14 days.
Covering and watering concrete requires significant material and labor costs. Therefore, in cases where the concrete surface is not intended for further contact with the mortar, protective films or special paint compounds (Etinol varnish, tar and bitumen emulsions, liquefied bitumen, etc.) can be used to protect it from drying out.
In the winter season, a whole range of measures is used to maintain concrete and

But besides him, there is a whole bunch of special magazines that a responsible work manager should know like the back of his hand. One of these magazines will be discussed in this article.

And so, let's talk about the magazine today concrete works... A sample is given in Appendix "F" SP 70.13330.2012 "Supporting and enclosing structures. Updated edition to SNiP 3.03.01 - 87 ". The electronic version of the journal can be downloaded for free at the end of the article.

What it is

This magazine is not large, the registration also does not take much time, but it must be filled out if concrete work is being carried out at the facility, this is established in paragraph 3.5 of SP 70.13330.2012. It is filled in by the responsible contractor on the days when concrete work is being carried out.

This joint venture contains a new form of the journal, the old form must already be written off. Keep this in mind.

Earlier I read somewhere that if the volume of concrete work does not exceed 50 m3, then it is not necessary to keep a log of concrete work and you can make entries directly in the general work log. But I just can't remember where I read it. If anyone knows, please write in the comments.

Below is an example of filling out a concrete work log. Click on the pictures to enlarge the image.

How to fill out?

Many people ask this question, but I think that everything is intuitively clear here and after reading the example of a completed magazine, many questions have disappeared, but still I will try to explain some points to you.

The magazine consists of a title page and a table of 14 columns. The first 8 columns are filled in by the responsible contractor, and from 9 to 13, the one who tests concrete structures for strength is filled out. Strength is tested at intermediate and design (28 days) age.

When you fill in the 4th column, try to indicate all the symbols for concrete. For example, if the project specifies to apply concrete B20F100W6, then indicate all this data in the log. If you indicate only the class B20 concrete in the concrete work log, then during the inspection the inspector of the state construction supervision may doubt the concrete used and demand proof of its compliance with the requirements of frost resistance and water resistance.

And you will have to prove this by presenting a quality document for the concrete mixture, and there, too, they may miss and not write data on frost resistance and water resistance. And you will have to do additional technical inspection of concrete structures. Do you need it?

The Concrete Works Journal, like all other magazines, must be numbered, laced and secured with the seal of the organization. Also, corrections and blots are not allowed in it. It is included in the list of as-built documentation and, upon completion of construction, is transferred to the developer, and then to the operating organization.

If concrete work is carried out at an outside air temperature of less than + 5 ° C, especially in winter, it will be necessary to keep a concrete care log. We will talk about him.

P.s If you still have questions, feel free to ask them in the comments, and I will try to answer them. Subscribe to the blog and be the first to receive new articles.

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P.s. Friends, I want to recommend you the program "Executive documentation" from the company "ALTIUS SOFT"... If you want to automate and speed up the process of maintaining executive documentation, then you cannot do without this program. Thank!