Classifications

• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04B—GENERAL BUILDING CONSTRUCTIONS; WALLS, e.g. PARTITIONS; ROOFS; FLOORS; CEILINGS; INSULATION OR OTHER PROTECTION OF BUILDINGS
  • E04B1/00—Constructions in general; Structures which are not restricted either to walls, e.g. partitions, or floors or ceilings or roofs
  • E04B1/62—Insulation or other protection; Elements or use of specified material therefor
  • E04B1/70—Drying or keeping dry, e.g. by air vents
  • E04B1/7007—Drying or keeping dry, e.g. by air vents by using electricity, e.g. electro-osmosis

Definitions

• the invention relates to a method for drying and protecting masonry from re-moistening by capillary water drawing from the substrate.
• a method is known from PL-PS No. 103 633 which enables this goal to be achieved.
• the water is transported downwards and the hydrophobic agent is transported upwards.
• the change in the transport direction of the liquid medium takes place by changing the polarity of the voltage applied to the electrodes versus the polarity that ensures downward water transport during drying.
• the introduction of the hydrophobic agent into the masonry is based on the principle of drawing the water upwards, which is caused by electroosmotic negative pressure which is directed upwards, this direction resulting from the change in the polarity of the voltage.
• the penetration area of the hydrophobic agent is not increased significantly above the level determined by capillary application of this agent.
• the change in the voltage applied to the electrodes of the electroosmotic system which takes place during the hydrophobization, which is preceded by drying, thus increases the penetration area of the hydrophobic agent. only insignificant and does not ensure that the possible sizes of the completely hydrophobized areas are reached.
• the reversal of the voltage applied to the electrodes of the electroosmotic system leads to a reduction in the hydrophobized region compared to the region which is penetrated by gravity in the previously electro-osmotically dried masonry by the hydrophobic agent.
• this method does not allow the masonry areas below the earth to be secured.
• the method also does not protect against the effects, which specialists in the field of architectural monuments maintain, which can be caused by changing the salt concentration in the wall. These changes are associated with the ion current during the current flow through the masonry, the ion conductivity, as well as with the electrolysis of the water. With regard to the slow salt enrichment with salt solutions that are taken up from the soil, which sometimes takes a few tens or even a hundred years, these changes are sudden and cause an increase in the salt content due to the inflow of migrating ions and electrolytic water decomposition to hydrogen and oxygen in the area of the masonry where the electricity flows. The progressive crystallization of the salts is the cause of the frequent formation of hard-to-remove stains and seizures on the surfaces of electro-osmotically dried masonry, in the immediate vicinity of the electrodes.
• the plus electrodes are arranged above the holes for hydrophobization after the masonry has been impregnated with a hydrophobic agent, the current flow through the hydrophobized area and the drying process are practically interrupted.
• the invention has for its object to increase the penetration of the hydrophobic agent into the masonry, to increase the uniformity of its distribution in the hydrophobization zone, to increase the resistance of the hydrophobic film on the walls of the pores and capillaries and the time it takes to dry and Shutting off the moisture related technological processes.
• the upper row of the plus electrodes is used in the masonry at a distance of up to 1 m from the minus electrodes, preferably in the vicinity of the floor surface.
• the distances between the electrodes within a row are determined depending on the size of the moistened area and divided into sections, which are fed by separate sources.
• the holes for the hydrophobic agent are drilled outside the area of influence of the electric field of the upper row of electrodes. In these holes during the Current flow continuously introduced the hydrophobic agent, which penetrates into the capillaries and pores according to the effect of the continuity of the current and the capillary and gravitational promotion and transmission and spreads where the electrokinetically transported water has been removed, thereby blocking the Moisture is formed.
• the method ensures that the drying efficiency is increased by the fact that the current appears in the circuit when the compulsory DC voltage is switched on and, the drying process begins, the effectiveness of which increases with the current value
• this current is its initial value, which occurs when the feed devices are switched on.
• electrochemical polarization phenomena occur in the masonry, the effect of which is the formation of a cell in the masonry which is charged by external force and whose direction of voltage is opposite to that of the external supply sources.
• the polarization voltage always increases with the current flow through the masonry. In the beginning it grows very quickly; it then approaches asymptotically to the specified value, which is approx. 6 V in typical electroosmotic systems, but often reaches up to 10 V.
• the electrochemical reaction of the masonry to the current flowing through it corresponds to the principle of "action-reaction", a reduction in the current flowing through this masonry, which is particularly visible in the initial period of drying.
• the aim is to limit the specified value of the polarization voltage as much as possible.
• this is achieved by reducing the expansion of the polarization source.
• the penetration range of the hydrophobic agent is expanded in relation to the area which is achieved by gravitation in previously dried masonry, and all the more in relation to the hydrophobization process according to PL-PS 103 633.
• the reduction of the area of the masonry located between the upper and lower electrodes enables the. Decrease and decrease the area where salinization occurs on the surface of the walls to be dried.
• the hydrophobized area is more extensive, more stable and more workable because the introduction of the hydrophobic agents takes place outside the current flow area, that is to say at the point where no additional salinization associated with water electrolysis occurs.
• the final salinity is even smaller than the initial salinity because part of the salt is removed with the water.
• the moistened masonry is divided into sections along which the plus electrodes are placed, which form independent sections, which are connected to mutually independent feeding devices, depending on the amount of moisture and performance of the feeding devices.
• Electrodes were distributed on the masonry at a height of 30 cm above the floor area with a distance of 40 cm.
• the electrodes were divided into two sections, each of which was connected to a positive pole of a separate supply device with a voltage of up to 24 V and a current of up to 1 A.
• a common minus electrode was connected to the minus poles of the feed devices.
• the minus electrode was placed in the ground around the building at a depth of 50 cm below the surface of the earth.
• the electrode was in the form of a galvanized flat iron, which was in the floor at a distance of 60 cm from the outer walls.
• holes with a diameter of 20 mm were drilled for the introduction of the hydrophobic agent. These holes were drilled every 20 cm at an angle of 30 ° to the horizontal and with a depth of 30 cm with a wall thickness of 51 cm.
• the individual sections of the plus electrodes were connected to the plus poles of the separate feed devices and the common minus electrode to the minus poles of the feed devices.
• Holes with a diameter of 24 mm were drilled at a distance of 20 cm above the plus electrodes for the introduction of the hydrophobic agent.
• the holes were made at an angle of 40 ° to the horizontal at a distance of 20 cm and with a depth of 45 cm with a wall thickness of 65 cm. drills.
• the hydrophobic agent which was prepared on the basis of silicone resins, was introduced into the holes. After one month from the completion of the work, the amount of moisture in the walls had dropped from the initial value to 8 to 10% and was less than 5% after four months.
• results obtained indicate the masonry of the building on significant shortening of the drying time.
• the chemical compounds were salted out intensively below the plus electrodes, specifically outside the zone of the hydrophobic barrier. In this way not only an acceleration of the drying process and an increase in the thickness of the hydrophobized zone in the masonry, son also achieved a significant increase in the resistance of the hydrophobic barrier.

Landscapes

• Engineering & Computer Science (AREA)
• Architecture (AREA)
• Civil Engineering (AREA)
• Structural Engineering (AREA)
• Water Supply & Treatment (AREA)
• Physics & Mathematics (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Electromagnetism (AREA)
• Chemical & Material Sciences (AREA)
• Electrochemistry (AREA)
• Investigation Of Foundation Soil And Reinforcement Of Foundation Soil By Compacting Or Drainage (AREA)
• Lining And Supports For Tunnels (AREA)
• Compositions Of Oxide Ceramics (AREA)
• Polyurethanes Or Polyureas (AREA)
• Separation Using Semi-Permeable Membranes (AREA)
• Drying Of Solid Materials (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (3)

Family

ID=20014972

Family Applications (1)

Country Status (5)

Cited By (2)

Citations (4)

• 1982
  • 1982-12-09 PL PL1982239422A patent/PL139278B1/pl unknown
• 1983
  • 1983-12-07 EP EP83112312A patent/EP0111306B1/fr not_active Expired
  • 1983-12-07 AT AT83112312T patent/ATE20935T1/de not_active IP Right Cessation
  • 1983-12-07 DE DE8383112312T patent/DE3364770D1/de not_active Expired
  • 1983-12-08 NO NO834523A patent/NO834523L/no unknown

Patent Citations (4)

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