|
|
(Image: Overview of the repair processes) According to EN 752-5 [DINEN752-5:1997], repair is understood to be measures to rectify local damages. These repair processes (Bild 5.2) include:
Repairs from outside are carried out to manhole structures as well as to the sewer itself. They require, among others the digging of an excavation. Repairs from … |
|||||
|
|
Protective handling of capillary pore materials that do not fill the inner pore system and do not form a surface film is called impregnation. When an impregnation hinders or makes more difficult the soaking of the surface of the structure with water and thus prevents the capillary suction of water, then one speaks of hydrophobic impregnation or, in short, of a waterproofing. Waterproofing is controversial as a stand-alone measure [Sasse94] and should … |
|||||
|
|
Sealing forms a continuous surface film that protects the pipe from external influences in the sense of a coat of paint. The thickness of the film on even surfaces is between 0.1 mm to approx. 0.3 mm, but somewhat more in rough depths. On rough peaks (aggregate grains or burrs) it declines towards zero. By means of infusion into the near-surface pore structure, this film adheres to the pipe and effects at the same time a fixing of the pipe in the … |
|||||
|
|
Film-forming coatings can consist of one or more layers. The type and quantity of the individual protective layers depends on the protective function, which result from the requirements and the loading [Sasse94]. |
|||||
|
|
The determining value for the thinnest layer thickness of mortar coating, according to [DAfStBa] is 5 mm for reaction resin bound mortar, 10 mm for plastics modified mortar and 20 mm for cement bound mortar. Besides this, the thickness of the layer should correspond to at least three times the largest grain diameter. The respective required layer thickness depends on the aims that are being pursued as well as the type of damage. If the coating is … |
|||||
|
|
An important differentiating feature of the coating process is the thickness of the coating. Thus there is differentiated (Bild 5.3.1.1) (Bild 5.3.1.1) (Bild 5.3.1.1) (Bild 5.3.1.1) :
|
|||||
|
|
Nov 23, 2004
The basic idea of the model of mechanical adhesion, according to [Biker68], assumes that the fluid adhesive (coating mortar) hardens in the pores and hollows of the adherent (concrete pipe) and is there -mechanically - anchored like a wall plug or press … |
|||||
|
|
Nov 23, 2004
The effective surface, as the sum of the contact surfaces between adhesive and solids, is the result of the wetting process. Under wetting (also dissemination) there is understood to include the adsorption and spreading of a fluid on a solid surface. Young [Young05] first reported on wetting experiments … |
|||||
|
|
Nov 23, 2004 Polarisation theory: In addition to the thermodynamic method of observation of border surface energies with the aid of wetting measurements and border surface energy characteristics, de Bruyn [Bruyn39] first created a connection between adhesion appearances and the electrical reciprocal effects of molecular dipoles. He traces the appearances of adhesion back to a sufficient approximation between molecules of the adhesive and those of an adherent to … |
|||||
|
|
Nov 23, 2004 (Image: Adhesive tensile strength between coatings without and with hydro-silicon content on mineral base [Sasse94]) With the availability of special spectroscopic analysis methods it has been possible since the 60's of the 20th Century to prove the existence of chemical adhesion bonds experimentally, especially between low molecular adhesives and adherents. To the adhesion bonds that have been experimentally proven several times, belongs the covalent … |
|||||
|
|
Nov 23, 2004 |
|||||
|
|
An important pre-condition for almost all the coatings carried out today is a fixed, powerful and durable bond to the pipe concrete. The creation of a bond rests on chemical/physical and mechanical processes that are defined as adhesion. Adhesion characterises the condition of the creation of a border surface layer between two material phases in contact. This condition is distinguished mainly in the cohesion of the participating phases, which are generated … |
|||||
|
|
Nov 23, 2004 The requirements to be made of coating materials for mortar coatings depend on the loading to be expected for the individual case. A separation must always be made between:
|
|||||
|
|
The main field of application for cement mortar coatings has ranged since the start of the 20th Century to the works or in-situ applied corrosion protection of steel or cast iron drinking water piping. Much experience has been gained and many publications are available that provide information on the requirements, the composition of mortar, layer thicknesses, types of application as well as the method of action of this corrosion protection. The following … |
|||||
|
|
Silicate mortar is a two-component pure mineral inorganic building material. As a rule, alkali silicate mortar consists of a modified, highly alkaline, silicate solvent as a fluid component. The powder components contain mixtures of various synthetic and natural latent-hydraulic substances, crystalline aggregates as well as other accompanying substances. In the alkaline silicate mortars, other than with cement-bound building materials, an amorphous … |
|||||
|
|
Nov 23, 2004 Mineral mortars are understood to be materials that have no plastics additives. In the following, the mortars belonging to this group will be described as cement mortars (Abschnitt 5.3.1.3.2.1) and silica mortars (Abschnitt 5.3.1.3.2.2). |
|||||
|
|
Nov 23, 2004 One possibility of targeted improvement of, among others, the bending-tensile strength, the adhesive-tensile strength, the resistance to chemical attacks as well as the resistance to diffusion, of pure cement mortars for coating is offered by the use of plastics additives to the cement mortar [Fiebr85]. These mortars are designated as plastics-modified cement mortars and in the English usage also as polymer-modified cement mortar (Polymer Cement Concrete - … |
|||||
|
|
Nov 23, 2004 By UP resins there is understood the solvents of unsaturated polyester in a polymerisable fluid monomer (e.g. styrol). The hardening reaction is a co- and mixed- polymerisation (among others between the unsaturated polyester and the vulcanised styrol) that requires the formation of a radical for completion. The radicals are contributed mainly by the organic peroxides (hardener) whose effecting mechanism is triggered either by heat (> 80° C) or, for … |
|||||
|
|
Nov 23, 2004 Only two basic types are used in structural work as standard resins, Bisphenol-A and Bisphenol-F as well as mixtures of the two. As the viscosities of the usual basic resins are not under approx. 6000 to 8000 mPa×s, viscosity reducers or so-called reactive thinners are used. Also, for lowering the viscosity, low molecular organic solvents are used above all for sealing. They must soften completely before the chemical reaction as otherwise substantial … |
|||||
|
|
Nov 23, 2004 Polyurethane is the generic term for plastics materials ranging from hard to elastic that are manufactured from polyalcohols and poly-isocyanates. The hardening reaction is a poly-addition. Two components are required in this reaction that must be available in an exact mixture relationship. Polyurethanes are characterised by their suitability for a large range of applications. It is possible, to a much larger extent than with other reaction resins … |
|||||
|
|
Feb 16, 2011 PMMA resins are polymerisates of monomers or pre-polymerised methyl-methacrylates with modified components. The hardening of the reaction resins takes place in the presence of a catalyser through peroxide to thermoplastics or duromers. In this process, the powdered hardener is added either to the solution of polymerisate in associated monomers (casting resin system) or in a mixture with polymer powder to the fluid monomer mixture (MoPo system). Whereas … |
|||||
|
|
Nov 23, 2004 If a mortar contains no cement and if the whole binding medium consists of a synthetic resin mixture capable of reaction at the usual construction temperatures, then one talks of a reaction resin mortar or, in short, of a PC (Polymer Concrete). In use are reaction resin systems based on unsaturated polyesters, epoxy resins and methacryl resins that are "cold hardening", i.e. they can harden completely at room temperatures. As a result of the lack … |
|||||
|
|
||||||
|
|
|
|||||
|
|
The testing of coatings of a sewer system also includes the general testing of the mortar, for example to DIN 18555 Parts 1 to 5 [DIN18555] or DIN 1164 Part 1 [DIN1164b], originally designed for testing cement, and EN 196 Part 1 [DINEN196], as well as the testing with respect to the specific requirements … |
11094 search results:
