EP1598504A2 - Method for protecting and for restoring construction elements subject to cracks like reinforced concrete elements - Google Patents

Abstract

The method involves determining the areas of the steel concrete part which are at risk of cracking, introducing a seam perpendicular to the main lines of stress and treating the seam with a pore-filling impregnating substance, introducing a gap filling hose (3) into the seam and then filling it out with a resilient mass (4). The walls of the seam are treated with a primer before the filler hose is introduced. The seam preferably has a width of less than 10 mm. Independent claim describes steel concrete part such as car park plate which has on underneath side a seam gap perpendicular to main stress lines filled as above.

Description

Description: (field of application)

This invention relates to the crack-bridging protection of new or crack-bridging Repair of existing crack-prone reinforced concrete or steel composite components. Independently from the static system is the according to DIN 1045 and the notebooks 525 and 526 of Durability and stability required by the German Committee for Reinforced Concrete Reinforced concrete or steel composite structures guaranteed by this invention. Of the Protection against the entry of concrete attacking (carbonation etc.) or corrosive (Tausalze, seawater, etc.) substances in the reinforced concrete or steel composite construction Parking garages, underground garages, floor slabs, flat roofs, etc. are thus ensured.

State of the art

The goal of protective measures is to increase the resistance of concrete components against the penetration of concrete attacking or corrosive substances and against mechanical effects on near-surface areas to ensure a required Useful life of 50 years. For the protection and in the given case the repair of concrete, come to ensure the durability of the structure after sufficient Preparation of the concrete substrate in principle next to the crack-filling and reprofiling Measures of the order of surface protection systems, mainly Crack-bridging systems. As binders are usually in these systems two-component, cold-curing reaction resins (epoxy resins, polyurethane-modified Epoxy resins, polyurethanes, etc.) used. Such coatings are significantly, extensive requirements. The main required properties are on the one hand high abrasion resistance and high chemical resistance and on the other hand good Crack bridging capability even under dynamic conditions.

Especially problematic is the simultaneous fulfillment of low wear and good static and / or dynamic crack bridging capability, since these properties are in opposite directions are and are almost mutually exclusive. To meet these requirements To be such coverings are applied in two layers. It should be the so-called soft, unfilled floating layer assume the function of crack bridging and the wear layer applied thereto ensures the abrasion resistance. Beside these Systems known as two-layer systems also use single-layer systems. Here, the system must meet both requirements.

As an alternative to the aforementioned RiLi-SIB crack-bridging systems, seals can also be used in accordance with ZTV ING, Part 7 Sections 1 to 3. The crack bridging becomes ensured in these systems by welding tracks or liquid plastics. The mechanical Resistance ensures a protective layer of cast or rolled asphalt.

According to DIN 1045-1, the exposure class XD 3 is decisive for directly driven parking decks, for which the calculated value of the crack width w _k = 0.3 mm under quasi-continuous loading must be proven for reinforced concrete components and under prestressing without composite. This value is also to be respected for the durability of the reinforced concrete decks of composite steel car parks. For flat roofs, this value is also sufficient to limit the crack width, unless lower crack widths are required by water impermeability requirements.

Disadvantages of the current procedure

Practice shows that the traditional crack-bridging surface protection systems According to the RiLi-SIB, the requirements of the combined crack bridging and wear resistance can not do justice, especially at low temperatures. The systems create a sufficient wear resistance at required crack bridging ability only insufficient. Therefore, these are also subject to permanent protection of the structure from concrete attacking or corrosive substances intended systems wear and must be serviced accordingly. In addition, it should be noted that a crack bridging Statics and structural design are not required in all areas is because these areas are permanently overstretched, i. H. are rude. So are the elaborate ones and wear-prone surface protection systems not necessary.

The seals according to ZTV-ING bring high construction heights with them. Therefore, the extra Loads of the protective layer in the statics. Likewise, the connection heights on ramps, stairs, etc. to observe. So sealing according to ZTV-ING usually find only in new buildings or in such repairs application, their buildings already were appropriately protected. Likewise put high costs, high machine use and elaborate application techniques further criticisms dar.

Furthermore, due to the mathematical limitation of the crack width from early or later force a statically unnecessary amount of reinforcement to be installed got to. So construction reinforcement is inserted into the component, which only for crack width limitation is necessary.

Object of the invention

• Hoher Verschleißwiderstand und rissüberbrückender Schutz in einem System
• Große Rissüberbrückung* >> 1,0 mm (*Risse infolge Schwinden, Verformung, Zwang (Temperatur etc.))
• Vorrichtung zur Rissüberbrückung darf keinem mechanischen Verschleiß ausgesetzt sein
• Hoher Verschleißwiderstand (gemäß Anforderungen OS 3 nach RiLi-SIB)
• Einfacher Einbau
• Für Neubau und Instandsetzung einsetzbar
• Geringe Aufbauhöhe
• Die eingebauten Sollrissstellen führen zu keiner Änderung des statischen Systems. Es werden weiterhin sowohl die vollen Normal- und Querkräfte als auch Momente übertragen.
• schlaffe Konstruktionsbewehrung zur Rissbreitenbeschränkung soll entfallen bzw. signifikant reduziert werden

The object of the invention is therefore to provide a durable, crack-bridging protection of the structure, which meets both the requirement of high wear resistance and sufficient crack bridging. The following aspects and parameters are to be considered:

• High wear resistance and crack-bridging protection in one system
• Large crack bridging * >> 1.0 mm (* cracks due to shrinkage, deformation, constraint (temperature, etc.))
• Crack bridging device must not be exposed to mechanical wear
• High wear resistance (according to requirements OS 3 according to RiLi-SIB)
• Easy installation
• Can be used for new construction and repair
• Low construction height
• The built-in break points do not change the static system. Both the full normal and transverse forces as well as moments will continue to be transmitted.
• limp construction reinforcement for crack width restriction should be eliminated or significantly reduced

In particular, on the basis of the last-mentioned point, it is a further object of the invention, to specify a reinforced concrete element optimized with regard to risk of cracking.

Solution of the task

• Ermitteln rissgefährdeter Bereich des Stahlbetonbauteils
• Einbringen mindestens einer Fuge senkrecht zu den Hauptzugspannungen
• Behandeln der eingebrachten mindestens einen Fuge mit einer porenfüllenden Imprägnierung (Zur Vermeidung der Hinterläufigkeit mindestens ca. 50 mm breit)
• Einbringen eines Fugenfüllschlauches in die mindestens eine Fuge, und
• Auffüllen der mindestens einen Fuge mit einer elastischen Fugenmasse.

Vorteilhafte Ausgestaltungen sind Gegenstand der Unteransprüche.To solve the problem, a method for the protection and repair of fracture-prone reinforced concrete components is proposed, which comprises the following method steps:

• Determine crack-prone area of reinforced concrete component
• Introducing at least one joint perpendicular to the main tensile stresses
• Treating the introduced at least one joint with a pore-filling impregnation (at least approx. 50 mm wide to avoid the occurrence of back-roundness)
• Inserting a Fugenfüllschlauches in the at least one joint, and
• Filling the at least one joint with an elastic grout.

Advantageous embodiments are the subject of the dependent claims.

Based on the static calculations / measurements, the arrangement of Dummy joints in calculated number and geometry in the area of the crack-prone areas. The location of the expected load-related cracks will be calculated before the action is taken determined and based on this, a joint cutting plan is derived for each individual case. Here, the dummy joints are arranged as Sollrissstellen so that the structure in his Structural behavior is not affected. The static system is retained, the Cutting forces will continue to be fully transferred. The cuts are in the area of the tension zones of the components depending on the reinforcement overlap. The depth of cut is lower as the minimum reinforcement coverage / minimum concrete coverage. Through these dummy joints can anticipate the expected cracks from load on the top deck become. These cracks are safely introduced into the dummy joint by a Fugenfüllstoff permanently protected as planned. According to Figure 1 b, the joint filling with a Permanently elastic grout ensured.

To ensure the durability is after cutting the joints with a pore-filling Impregnation (see also EP 1 102 731 B 1) treated the entire joint surface, so that a roughness of the subsequent joint filling is permanently excluded.

Here is a constructive detachment of the substrate by driving a joint hose generated. Between joint hose and joint floor usually remains a cavity, so that a two-sided adhesion is realized. So the elongation at break of the Fugenfüllstoffes be fully exploited. A large crack bridging capability is thus realized. Due to very small joint widths (i.d.R. << 10 mm), the joint filler is protected against mechanical damage Load (car tires, etc.) protected. A conical rounding can be the cutting edges if necessary, depending on the quality of the concrete, against mechanical stress to back up.

The entire concrete surface is then rigidly protected after the joints have been filled (cf., EP 1 102 731 B 1: Method for sealing porous building materials and components).

Depending on the type of construction, not only the load-related cracks but also cracks can be obstructed Deformations (compulsion) arise. It is important to distinguish between cracks due to runoff the heat of hydration that occurs at an early age during the hardening of the concrete, and cracks due to later compulsion (eg, temperature, shrinkage).

Cracks of early compulsion (heat of hydration) are already released during the application of the Fugenfüllstoffes and the surface protection system (see EP 1 102 731 B1) treated and thus also permanently protected. By very early after treatment of the concrete with a suitable surface protection system e.g. EP 1102 may crack from early compulsion depending on Construction can also be completely prevented.

Due to the high crack bridging ability of the joint filler is in the individual case on the Shaped joint system coordinated concept for a reduced crack width limiting Minimum reinforcement worked out. This results in a considerable savings potential limp reinforcement, resulting in significant cost advantages for the entire construction project leads.

Advantages of the invention

• High wear resistance and crack-bridging protection in one system
• Large crack bridging * >> 1.0 mm (* Cracks due to shrinkage, deformation, constraint (temperature, etc.))
• Crack bridging device is not subject to mechanical wear
• High wear resistance (according to requirements OS 3)
• Easy installation
• Can be used for new construction and repair
• Low construction height
• The built-in break points do not change the static system. It continue to transmit both the full normal and lateral forces and moments
• No vertical and transverse offset of the cut edges, since the reinforcement layer continues to be the pending function takes over
• Targeted anticipation of static crack formation in the crack-bridging protected dummy joint
• slack construction reinforcement for crack width restriction can be omitted or be significantly reduced

The mentioned further object is achieved by a reinforced concrete component in which it is In particular od a parking garage door. Like. Can act, with at least one reinforced concrete Einfeldplatte and with at least one beam, which is characterized that the at least one Stehlbeton Einfeldplatte at the gates to the at least a sub-structure articulated by waiving the upper reinforcement and that each Unterzugseite a joint is provided perpendicular to the main tensile stresses.

In contrast to the described method, it is not the case that the Construction resulting cracks or crack zones accepted and then protected. Rather, by a process optimized reinforced concrete part itself the construction designed so that superfluous (only the crack width limitation serving) reinforcement is omitted and instead of usually several, z. B. parallel joint cuts, only a joint cut per Unterzugseite is required. This results in significant cost advantages.

For the transmission of shear forces and normal forces in the concrete joint, the at least a reinforced concrete single-span plate a diagonal, anchored in the beam suspension on.

characters

FIG. 1a

shows a section through a reinforced concrete component with beam

FIG. 1b

shows a joint of Figure 1a

FIG. 2a

shows a perspective view of a parking garage ceiling

FIG. 2b

shows a section through the parking garage ceiling of Figure 2a

FIG. 3a

shows the joint cutting guide and the torque curve in a conventional Reinforced concrete floor

FIG. 3b

shows the joint cut and reinforcement guide and the torque curve articulated suspension of reinforced concrete ceilings

FIG. 4

shows the application with a reinforced base plate.

Description of exemplary embodiments

By way of example, the use of this invention is based on a parking garage in solid construction be explained.

To ensure the durability after the production of concrete pavements the basis The static analysis and the joint plan corresponding Sollrissstellen / dummy joints 1 cut. The maximum width is 5 mm and the depth is 30 mm. It should be noted, the cutting depth is above the minimum concrete cover 2. Therefore, before cutting the joints to determine the concrete cover with appropriate measuring instruments.

The static function of the reinforced concrete component is retained without restriction, as by the joint cut only anticipated the formation of cracks anyway expected in the tensile zone and the crack site is located at the location defined by the crack. The bending and shear resistance becomes - as usual in solid construction - for condition II (torn condition) determined.

Subsequently, in the course of the application of the surface protection system 5 joint hose 3 and 4 filler introduced according to Figures 1a and 1b.

Accordingly, the invention can also Hoesch additive blankets (as an example of a steel composite construction) be applied (see Figure 2).

With the so-called Hoesch Additive blanket, the same principle results. According to the Construction experience and static calculation result in cracks of constraint and bending always above the undercarriage, while the field area in parking garage interchanges non-cracked remains. Therefore, the cuts are guided to the left and right of the beam and filled, so that the reinforcement and the steel components are protected against corrosive media become. The stainless steel reinforcement can be omitted, since the crack width movement of the grouting is absorbed and the cross section is thus tight. The joint thrust from tiled beam effect can be done over the unattenuated residual cross section.

Hereinafter, an exemplary embodiment of a parking garage is still shown. This is a reinforced concrete single-plate, which at the gates to the beams is hinged up. The absorption of the lateral forces is carried out by an oblique and Longitudinal reinforcement, which connects the plate with the beams frictionally. At the top The plate is a Fugenschnitt, which is resistant to the ingress of chlorides etc. protected by the method described. Compared to reinforced concrete flow systems, in which as a result of the torque curve usually requires several cuts can, with the illustrated system, the location of the crack site through the concrete joint can be specified with a specific cut per unit side. This will make the system very economical, as the field areas remain unscheduled, and thus no need further protection. In the reinforced concrete slab, the usual upper reinforcement is dispensed with, and replaced by a diagonal suspension bracket anchored in the beam is. Thus both lateral forces and normal forces can be transmitted in the concrete joint. The crack width results in bending from the Tangentenverdrehung the Einfeldplatte and at train from the elongation of the lower reinforcement and is determined by the method described permanently protected.

The system can also be used for the protection of reinforced floor slabs (Figure 4). Here, in the gusset areas section A is the (possibly only there existing) upper and sever the (continuous) lower reinforcement. In the standard areas, the bottom reinforcement (section B) not cut. Thus, a Aufschüsseln the bottom plate avoided in area A.

Claims (10)

Method for protecting and repairing crack-prone reinforced concrete components, comprising: Determining crack-prone area of Stahlbetunbauteils Introducing at least one joint perpendicular to the main tensile stresses Treating the introduced at least one joint with a pore-filling impregnation Inserting a joint filling hose into the at least one joint Filling the at least one joint with an elastic grout A method according to claim 1, characterized in that prior to the introduction of the joint filling hose, the walls of the at least one joint are treated with a primer. Method according to claim 1 or 2, characterized in that the at least one joint has a width of less than 10 mm, A method according to claim 3, characterized in that the at least one joint has a width of less than 5 mm. Method according to one of the preceding claims, characterized in that the maximum depth of the at least one joint is smaller than the concrete cover of the reinforced concrete component. Method according to one of the preceding claims, characterized in that the pore-filling impregnation consists of a substance / substance mixture according to EP 1 102 731 B1. Method according to one of the preceding claims, characterized in that after introduction of the joint filling hose into the at least one joint between the joint filling hose and the bottom of the joint, a cavity remains. Reinforced concrete component, in particular parking garage door od. Like., With at least one reinforced concrete Einfeldplatte and with at least one beam, characterized in that the at least one reinforced concrete Einfeldplatte articulated at the gates to the at least one beam by dispensing with the upper reinforcement and that ever Unterzugseite a joint is provided perpendicular to the Hauptzugspannungen. Reinforced concrete component according to claim 8, characterized in that the at least one reinforced concrete Einfeldplatte has a diagonal, anchored in the beam suspension reinforcement. Reinforced concrete component, namely elastically bedded bottom plate, characterized by a continuous lower reinforcement, vertically crossing, spaced joints, the bottom plate in the region of the crossing points has an additional upper reinforcement, and wherein the joints in the region of the crossing points sever the upper and lower reinforcement layer and in the remaining area the maximum depth of the joints is smaller than the concrete cover of the reinforced concrete component.

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