DE8902256U1 - Test facility for a waterproofing system for civil engineering structures - Google Patents

Description

· ^: ··'·&Tgr;&Idigr;89··02"256.'4'/··23.05.1989

-3- G89

Description

Annette Becker 5300 Boan

IC test device for a seal

for civil engineering

The innovation relates to a test device for a seal for engineering structures or the like, containing at least one sealing layer composed of plate-shaped elements made of corrosion-resistant sheet metal, such as stainless steel sheet, for application and bonding to a solid structural base layer, such as a concrete layer with a fine layer, in order to test the welded joints for possible leaks after completion of the seal.

Sealing on buildings is intended to prevent water or liquids, regardless of type and origin, from having a harmful effect on the building and its construction. This includes corrosion protection, i.e. protection against chemical attack. In addition, sealing on engineering structures has the task of preventing the controlled sealing off of harmful liquids. This particularly affects industrial basins, such as oil collecting basins, tank basins, cooling water basins, fire ponds, wet operations, shielding of tanks, apparatus and systems in the chemical industry, sewage treatment plants, waste disposal sites, etc.

-4-

Sealing of industrial buildings has so far been carried out mainly on the basis of plastic foils as a sealing layer in one or more layers. However, there are buildings in which plastic foils as a sealing layer do not fulfil all ⁵ functions, for example they do not allow access or are subject to combined chemical attack.

H cannot adequately withstand various harmful substances. It is therefore already a waterproofing for civil engineering structures

has been proposed in which a sealing layer made of plate-shaped elements made of corrosion-resistant sheets, such as stainless steel sheets, is applied and glued to a structurally solid base layer, such as a concrete layer with a thin layer, and the joints between adjacent elements are designed as expansion joints and welded together tightly. In particular, the sealing layer is formed from plate-shaped elements made of stainless steel sheets, possibly with angled edge strips on the sides, which are glued to the substructure using a reaction resin adhesive, particularly over the entire surface. Such a sealing layer is able to absorb thermal expansion during temperature fluctuations of up to 100 ⁰ C and more, without being subject to warping or stress cracks. The use of stainless steel sheets, for example in accordance with OIN standardized

Qualities V4a or V2, ensures the long-term

chemical resistance and corrosion resistance. The use of stainless steel sheets with a thickness of 0.8 mm to 1.0 mm is sufficient to achieve the desired resistance and strength of the sealing.

However, the requirement is regularly made to be able to check the tightness of such a seal immediately after completion, but also at later points in time. In the case of seals based on plastic films, it is known (see DE-PS 30 ?&Lgr; 811) to install an electrical conductor in the area to be sealed and seams made of insulating material, and to

-5-

Scanning the sealing layer with a search electrode to detect defects in the sealing by means of the spark discharges that occur at the defects. However, this test method cannot be used for a sealing layer based on metallic elements.

The innovation is therefore based on the task of creating a testing device for a seal based on metallic elements, with which the tightness of the seal can be tested immediately after completion and at any later

Time can be checked, ö&pgr;&eegr;6 the nbuiCntüii'j ZU

to damage.

According to the innovation, the task set for a seal of the generic type is solved by a tubular perforated test line that can be inserted in the area of the expansion joints and has an external diameter of less than 4 mm, in particular equal to or less than 3 mm, and an internal diameter of less than 2 mm, in particular equal to or less than 1 mm. According to the innovation , the tubular test lines to be arranged in the area of the expansion joints under the sealing layer can be tested for any leaks by detecting escaping gas after the seal has been completed using an inert gas, in particular a noble gas, introduced into the test lines and scanning the seal and the welded joints. The space available in the expansion joints is therefore used to install the test device according to the innovation, which does not hinder the seal. The innovation makes it possible to test the seal along all expansion joints in sections at any time without destroying them. By using an inert gas, especially a noble gas, no harmful effects are exerted on the sealing elements, so that corrosion or stress cracks cannot occur later. The test line built into the seal in the expansion joints requires

no additional space.
35

(For a possible even distribution of the in the lines

··» t·t

·*■· * ««It

-5a- ·

To ensure the correct flow of the gas introduced, the test lines are perforated, for example with holes or slots that allow the noble gases to escape at greater intervals along the line into the joints and gaps. To ensure that only small amounts of the test gas can escape, the holes in the test line are very small and made using a laser beam.

-6-

This introduction of a test gas into the test lines can be repeated at any time, even years later, so that leaks in the welds or stress cracks or other leaks in the seal can be detected.

r can be found. The escaping test gas can be detected at the exit points using a leak detector and displayed optically and/or acoustically.

The seal can be tested for leaks section by section at any time without damaging it by introducing a test gas under pressure that has no harmful effects on the seal.

The test cables are laid in individual sections,

for example in a continuous expansion joint, formed 15

along the side edges of the plate-shaped elements of the sealing layer. The test lines are advantageously made of corrosion-resistant metal pipes with an outside diameter of less than 4 mm, in particular equal to or less than 3 mm, and an inside diameter of less than 2 mm, in particular equal to or less than 1 mm. However, it is also possible to make the test lines from high-temperature-resistant plastics which are welded together by welding. The elements are not ^welded together with the same dimensions. The perforation of the pipes or hoses consists of very small holes which are machined into the pipe or hose walls, for example using a laser beam.

In order to ensure that the test lines can be connected at any time in order to introduce test gas and at the same time the sealing layer is not interrupted, a further proposal of the innovation is to equip the test lines, which are arranged in individual sections, with an external connection, such as a pipe socket.

In particular, the external connections, if the structure 35

permitted to be installed on rising walls.

• · 4 « t

* β f I

-7-

According to another suggestion, the test lines in a larger seal do not form an interconnected system but rather individual sections that can be checked separately. This also makes it possible to specifically check only certain particularly vulnerable or conspicuous areas during inspections.

The butt joints of the plate-shaped elements of the waterproofing layer are also subjected to

The protective cover is welded throughout in order to ensure that 10

To prevent the occurrence of crevice corrosion on the elements.

The invention can also be used advantageously here by inserting the test lines into the expansion joints before welding the joints of the elements of the sealing layer.

and welding of the joints under protective gas by 15

The protective gas is introduced into the test lines.

The shielding gas during welding and the test gas during subsequent leak testing can be identical, for example based on helium. By introducing the shielding gas during

Welding into the test leads can not be as

quickly and it is ensured that it remains in the expansion folds and gaps along the joints of the elements to be joined during welding.

The invention is explained by way of example in the drawing.

show

Figure 1 the perspective view of a c ¹ =»ttenf örmi element

Figure 2 Partial view of a seal made of welded elements

Figure 3 Cross section AA according to Figure 2 for a transverse joint

Figure 4 perspective section of the seal with longitudinal joints of the elements

Figure 5 schematic cross-section through a tank with sealing

Figure 6 schematic cross section through a test line

Figure 7 Cross section through a test line in the seal with external connection

Figure 8 schematic view of the structure of a seal with elements according to Figure 1 and test lines.

The base element for the sealing layer made of corrosion-resistant sheets, in particular made of stainless steel, and possibly also copper, for large flat surfaces, which are arranged at a slight incline to drain the liquids to be collected, is formed by the plate-shaped element 1 according to Figure 1. These plate-shaped elements are combined to form a closed

Sealing surface joined together, see Figure 2, and under Expansion of expansion joints, along their abutting

Edges are welded tightly together. This creates continuous longitudinal weld seams 6 and transverse weld seams 2. In particular, these weld seams 6 and 2 must be welded immediately after

be tested for leaks during production and during the Years again and again to check for possible

to detect corrosion damage at an early stage. The elements 1, for example made of stainless steel sheet, must be connected to one another to form the continuous sealing layer via expansion joints in order to compensate for thermal expansion, for example as a result of

^u weather influences. According to the invention, the test lines in the form of pipes or hoses are also introduced into these expansion joints, through which a test gas under pressure can be introduced to any point. This gas escapes at leaks in the sealing layer, ie the elements and welds, and can be detected.

• a····· ·· UlL ·♦ ··

The element 1 should have a manageable length 1 of about 1 ra to 2 m, a width bl of the support surface 12 of about 50 to 100 cm and a thickness of about 0.8 to 1.2 mm. The element 1 is rectangular and tubular in shape, in which an edge strip 10, 11 is angled upwards along two parallel sides. The angle OC is about 85 to 88°, ie the edge strips are slightly angled outwards. The elements 1 are arranged next to one another on a substructure, see Figure 4. In the longitudinal direction, the edge strips 10, 11 form a V-shaped expansion joint 20, the size of which is determined by the height h of the edge strips 10, 11 and the angle OC . The height h of the edge strips 10, 11 should be approximately 20 to 50 mm, the distance a at the foot of the expansion fold approximately 3 to 6 mm. The substructure, see Figure 4, is e.g. a concrete layer 3, which is covered on the top with a smooth fine layer 4, such as a screed. The fine layer can be slightly inclined in a desired direction with a gradient of 1 to 2 % . A cold-setting reaction resin adhesive 5 is applied over the entire surface of the fine layer 4, e.g. an adhesive based on polyisocyanate reaction resins, which sets by contact pressure and does not require a long curing time. The elements 1 are placed one after the other on the adhesive layer 5 and the test line 40 is inserted along the edge strips 10, 11 into the expansion joint 20 that is being formed. The test line 40 is, for example, as shown in Figure 6, designed as a stainless steel pipe with an outer diameter of 3 mm and an inner diameter of 1 mm, in the pipe wall of which small holes 41, which are produced, for example, by means of a laser beam, are provided as perforations at intervals of 30 to 40 mm. Such a pipe 40 as a test line is, for example, continuously introduced into the longitudinal expansion joints 20 of the sealing layer formed by the raised edge strips 10, 11, see also Figure 2. At one or both ends of the seal or the continuous expansion joint 20, the pipe end 46 of the pipe is led out of the seal, as shown in section in Figure 7, for example. Such a

-;—&igr;.&igr;

The pipe end 46 accessible for connection is preferably provided on a rising wall 3C of the structure to be sealed. The elements 1 are also led up such rising walls with bends 13, forming expansion joints, and are also sealed at the end opposite the wall 30 in the area 18. The test line 40 is laid in the cavity H formed by the expansion joint and is led out at an angle through the recess 43 in the element 13 of the sealing layer. In order to seal this breakthrough, the pipe socket 42 is welded onto the element 13 of the sealing layer, for example, see weld seam 44, and the test line 40 is attached to the end of the pipe socket in a sealed manner using brazing. Now, by means of a gas cylinder 50, by placing it on the pipe end 46 in the direction of arrow F, a test gas, for example helium, can be introduced into the pipe 40 and via the holes 41 into the cavity H in the expansion joints below the sealing layer of the elements 1. The test gas introduced through the test line 40 will fill all the cavities within the sealing layer and will tend to escape upwards through the sealing layer if there are gaps. Such test gas escaping from the sealing layer, e.g. at weld seams, can then be detected and displayed using a leak detector. This allows corresponding leaks in the sealing layer to be found and resealed. After the test process has been completed, for example of an expansion joint 20 running along the length of the elements, the gas supply is turned off and the pipe socket 42 is closed by screwing on the screw cap 51. The next section can now be tested by introducing the test gas into the test line of the next expansion joint 20, see Fig. 1g. ü.

When producing the seal, after the test line 40 has been inserted, the butt joint, see Figure 4, is sealed almost without a gap and the elements are weighted down with stones in their final position so that they bond to the substrate through contact pressure. The butt joints are pressed together and, at the same time,

int «·· «·_■»&♦ · ··

Inert gas is injected into the expansion joints 20 and the pipes 40 are fixed to one another at intervals by spot welding 9. When all elements 1 are glued to the substrate and spot welded along their edge strips, the final sealing and sealing of the sealing layer formed from this can be carried out by welding the butt joints continuously under inert gas. The inert gas entering and remaining in the area of the expansion fold 20 prevents stress and crevice corrosion of the stainless steel sheets of the elements from occurring as a result of welding. The seal created in this way, see Figure 8, is both impermeable to liquids in arrow direction B to the substructure and in arrow direction C out of the substructure. It is also possible to place gratings 7 or the like on the elements 1 for walking on. By fully bonding the elements 1 to the substructure, they are protected against slipping and warping. The expansion folds 20 allow the necessary thermal expansion compensation and provide space for the permanent accommodation of the test cables 40. The elements 1 can be relatively long, but it is not to be forgotten that in the case of large surfaces to be sealed, abutting elements must be connected to one another at the transverse sides, see Figure 2, the transverse weld seams 2.

Figure 3 shows a possible design of a cross weld seam according to section AA of Figure 2. The cross weld seams must also be designed as expansion joints. At the same time, they are laid in the element plane so that the drainage of liquids in the direction of arrow E with a slight gradient is possible and is not hindered by an upstanding weld seam. The expansion joint of the cross connections is therefore laid in the substructure, see Figure 2. The groove 31 is milled into the fine layer 4 and, if applicable, the concrete layer 3. This groove is created before the adhesive layer is applied. A cover, for example a copper sheet profile 22 with a U-shaped cross section with lateral support flanges, is hung in the groove 31 and attached to the support flanges with the

Adhesive layer 5 is glued. The elements 1 are designed according to Figure 1 to produce the transverse joints, which is not shown in more detail, with downwardly angled edge strips 14, see Figure 3, on the transverse sides. The elements 1 are then hung in the groove 23 of the profile sheet 22 with the downwardly angled edge strips. The expansion joint 19 remains between the two adjacent edge strips 14 of the adjacent elements 1 and is tightly sealed on the top in the element plane by the weld seam 2. There is enough space _in the groove 23, which as a whole represents the cavity for the expansion joint of the transverse weld seams 2, to insert the test line 40, for example a perforated pipe according to Figure 6, continuously over the elements arranged next to one another, see Figure 2. At the lateral ends of the transverse weld seam 2 or groove ti, the test line can be led up at least on one side and led out of the sealing layer in order to form a connection, as shown schematically in Figure 7, for example, for blowing in test gas. This connection can then be tightly closed by means of a screw cap.

Figure 5 shows a schematic cross section through a

sealed collecting tray with substructure made of concrete 3, which is bordered by laterally rising walls 30 and has the collecting channel 21 for waste water or the like on one side. The tray runs to the collecting channel 21 with

slight slope in arrow 1 direction E. The sealing is applied to the bottom of the collecting tray as described above and see also Figure 8. The elements 1 are led up from the bottom of the tray to the adjacent rising wall surfaces 30 via bends marked 13.

The expansion joints are also formed and

and all joints are welded tightly. The collecting channel 21 is also lined with a sealing layer made of elements made of stainless steel sheets Ib, which are glued to the substrate via the adhesive layer. **** Expansion joints are created, if required, in the manner of the cross joints, see Figure 3, or where permitted, by means of raised

Edge strips with expansion joints 20 and weld seams 6 are formed. Outside of flat surfaces, the sealing elements are made of corrosion-resistant sheets in the necessary configuration, for example as a U-profile 1b or angle la. Sealing elements adapted to these special configurations of the structure are also formed, as far as possible, at suitable points, expansion folds, in particular at the transition to the flat elements of the sealing layer or the lateral connections.

After completion of the sealing layer from elements 1 and special additional elements adapted to the structure configuration such as Ib, la, the entire sealing, see Figure 8, is tested section by section with test gas, which is filled into all gaps and joints via the pipes 40. The

Weld seams 6, 2 are scanned from the outside with a

Leak test device to locate escaping helium. Leaks can be re-welded. After the test procedure is completed, a cap is screwed onto the pipe socket and the pipe outlet is thus tightly sealed. Such a

Leak testing for leaks in the seal can lead to

can be repeated at any time. When producing seals for aggressive media, high-quality corrosion-resistant materials must be used for all materials used in the sealing layer, for which

Stainless steel sheets and pipes are particularly suitable. Depending on the requirements of the sealing, other metals and possibly plastics can also be used.

Claims (6)

G 89 012 17.04.1989 Protection claims 1. Testing device for a seal for engineering structures or the like, containing at least one sealing device composed of plate-shaped elements made of corrosion-resistant sheets, such as stainless steel sheet, for application and bonding to a solid structural base layer, such as a concrete layer with a thin layer, the joints of adjacent elements being designed as expansion joints and welded together continuously in order to test the welded StQBe for any leaks after completion of the seal, characterized by a tubular perforated test line that can be inserted 1 m into the area of the expansion joints and has an outer diameter of less than 4 mm, in particular equal to or less than 3 mm and an inner diameter of less than 2 mm, in particular equal to or less than less than 1 mm.
20 2. rrUf ei&Pgr;&Ggr;iCntüriy riöch claim I, characterized in that the test lead has holes or slots. 3. Test device according to one of claims 1 or 2, characterized in that the holes in the test line are very small and are produced by means of a laser beam. 4. Test device according to one of claims 1 to 3, characterized in that the test line is provided with a connection, such as a pipe socket. 5. Test device according to one of claims 1 to 4, characterized in that the test line consists of corrosion-resistant metal tube. - ¹ Z- * 6. Test device according to one of claims 1 to 4, characterized in that the test line is formed from a hose made of high-temperature-resistant plastic.