Prospects  for  the  development  of  methods  for  improved  concrete  hardening  in  the  XXI  century.  PART  2
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Protect the surface of the concrete floor
To protect the concrete floor, which is operated in the normal mode, or is subject to wear in areas with high traffic, there are several ways to protect the surface.
   Comparable ways: their cost, appearance and ability to perform the task to protect.
   In this article, we consider three ways to finish and protect the floor. Each of them has its advantages and disadvantages.
   Thin fil...

Finishing compositions based on water glass. Part 3
When used as part of exhaustion moderator comes coagulation and solidification of liquid glass. However, due to the presence in the composition of Portland cement with a finishing time is an increase strength of the coating due to hydration of cement minerals. Thus from colloids formed during the coagulation liquid glass are actively assigned to the water for hydration of cement, a porous media formed tumors filled Portland cement, which leads to...

Finishing compositions based on water glass. Part 2
Studies in Berlin Institute Federal institute for Materials Research and Testing, show that the average density of 1730 kg/m3 brick large proportion of pores having a size in excess of 1 micron is more than 90% [3] and they are responsible for the increased migration of fluids through brickwork.
   Most fully meet these requirements structure obtained by coagulation and water-soluble potassium silicate forming silica with a high sp...

Modernization and repair of self-propelled machines. (3)
Hardening electrolysis BORATING hinge pins and bushings mates working equipment hydraulic excavators EO-4121 (EA-4321) gives an increase in wear resistance 4-6 times compared to the bulk quenching details.
   Taking into account the high wear resistance of brazed blades, hardened sintered alloys (see Table 1), are recommended for carbide knives dumps graders DZ-122 and RS-98, combined machine E-405 based on KAMAZ, for front dumps a t...

Specialized exhibition Architecture. Construction (END)
Mari-lime brick and gas silicate blocks
   JSC "MZSK" produces silicate brick and a half, color (white, yellow, black, red, blue, green, brown).
   For the production of silica brick used quartz sand from quarries near the plant. Limestone enters the factory with Dobryatinskogo deposit Vladimir region. Silicate brick (Table 1) is used for masonry exterior and interior walls of buildings and structures, as well as ...

Geophysical processes primers and security. Part 5
In the center of Moscow can distinguish vertical structure comprising a crashing into the Earth`s crust magma elongated cylinder (Fig. 2) [5]. In the center section marked lack of extensive vertical zone converted waves ("blind spot"), going from the depths of 70-80 km to 7.5 km. Such "blind spots" are characteristic of the earth`s crust with the introduction of monolithic dense mantle rocks such as gabbro, diabase, etc. In such a zone Tashkent e...

Finishing compositions based on water glass. Part 1
The quality of the decoration of buildings for new construction and reconstruction depend not only on their aesthetic, but also the operational parameters, as good-quality finish - a guarantee of durable service basic designs, long maintenance-free operation, the costs for maintenance and care. Traditional binders used for the production of finishing compositions, liquid glass is widely used, but it has some drawback: coatings based on it gaining...

On possible amendments to the equation Griffiths
Griffith presented a picture of destruction allowed to formulate the problem of determining conditions of the beginning of crack propagation and find its general solution.
   As seen from the above schemes, in the process of crack propagation material directly adjacent to it "coasts" unloaded relaxes. This means that the stress and strain it decreases, and the elastic energy stored earlier in this area of ​​the body is re...

Construction skyscrapers - the requirements of modernity. Part 4
The program is a high-rise building in Moscow
   The project is now a high-rise building in Moscow is implemented in two main areas: the construction of business center "Moscow City" and implementation of the program of the Government of Moscow "New Ring of Russia."
   1. Moscow international business center "Moscow - City"
   The project includes the construction of buildings on the territory of abou...

Degree project - beginning of the road. (3)
Given the great diversity of subject matter and content of diplomas in various specialties, the jury is faced with great difficulties in determining the winners - "Who better violinist or a dancer?". Nevertheless, often based on emotional perception and can estimate the relevance and novelty, and the author`s contribution to the thesis project or job. Absolute winners in recent years have been graduates of Rostov CSO GASU St. Petersburg, Nizhny N...


 Information for builders



 Prospects  for  the  development  of  methods  for  improved  concrete  hardening  in  the  XXI  century.  PART  2

   For structures and massive middle massiveness expands the use of pre elektrorazogreva concrete mixtures. Improved installation elektrorazogreva concrete "pipe in pipe" constructive solution which is made in St. Petersburg LM Kolchedantsevym and Vladimir A. Arbenevym, minimize power consumption, make the process elektrorazogreva easier and more convenient. It should be noted that in constructions of concrete concreted preheated mixture formed favorable Thermo-stressed state, which eliminates the occurrence of cracks therein.

   In massive structures are still profitable and technically and economically feasible to withstand concrete method thermos. Laying preheated concrete mixes such structures greatly enhances the thermos method at the lowest cost of electricity (40-60 kWh/m3 concrete).

   Will expand the use of electric heating in the form of concrete formwork heating with different types of heaters in the construction of monolithic and precast concrete products. Promising are heaters designed AA Afanasyev, providing a completely uniform temperature field on the surface of the deck. Will be used as a heater heating wire. In the future, will be applied to the polymer wire heating the conductor design VP Lysova is flexible and easy to work.

   For structures with a large surface neopalublennoy appropriate use of heating will be covered (mats). With the installation of insulation on top of them will significantly increase the uniformity of the temperature field in the design and reduce the heat loss to the environment, thus reducing energy consumption.

   In factories defroster is advantageous to use as heating stands. In the production of sandwich panels heating stand will be used in the completion of the heating blankets.

   Electrode heating is used, etc., but its application is reduced due to the difficulties in the heat treatment of reinforced structures. In addition to the traditional rod and strip electrodes will apply sputtered zinc electrodes, allowing 20 times to reduce the consumption of the metal on the electrodes.

   The factories receive widespread heating of products in an electromagnetic field (induction heating), in particular in the heat treatment of reinforced concrete pipes, masts for the grid and other structural elements with dense uniformly distributed over the cross section reinforcement.

   On construction sites, this method is economically and technically advantageous to warm the joints of precast concrete with lots of reinforcement.

   In the new century, undoubtedly, will be used for heating concrete unconventional alternative energy sources. At the end of the twentieth century developed highly effective techniques in the production of heating concrete precast products in landfills with solar energy (solar technology). For solar technology has made millions of precast products in the southern regions of the country (in the Astrakhan and Volgograd regions, Krasnodar and Stavropol territories, as well as in Kalmykia and the Caucasus), thus saving large amounts of electricity.

   Ample opportunities are open to concrete, hardening in the cold, that extremely important for Russia. Now developed a new environmentally friendly antifreeze additives with freezing -45 C. Their use in the autumn and spring can give a good effect. In winter, especially when severe frosts, they are small quantities will be useful in combination with the heating. This will easily be laid in concrete mix gustoarmirovannye columns, walls, piers, beams high altitude and other similar structures without it freezing of rebar and formwork, and you can start heating concrete. This method worked well in the important construction sites in Moscow.

   It is possible that there will be effective supplements that produce large amounts of heat in the alkaline environment of concrete, resulting in rapid heating of the concrete before laying into the design.

   Economical use of electricity is primarily dependent on the correct method of heat treatment in the manufacture of concrete products, features or construction companies and a number of other factors. No universal methods, each method has its advantages and optimal application.

   When using technically and economically rational method of heat treatment of concrete greatest effect can be obtained in the automatic control process warming. Automation of heat treatment of concrete will not only ensure economical use of electricity, but also make the process of managing this process easier, more efficient and more reliable.

   In general, before the science of the next century the task of production workers to give effective, environmentally safe, low-power and cost-effective methods of intensification of concrete hardening while ensuring the highest quality and durability of precast and monolithic reinforced concrete structures.