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(Image: Construction of a masonry manhole) Since 2000, masonry structures in sewer systems that are newly built or rehabilitated have to be made of sewer bricks of a low porosity that are at least 24 cm thick (one brick) and have fully and evenly filled cement mortar joints without air inclusions. They have to be jointed on their inside (mortar group III with additives) [ATVA157]. The joints are to be smoothed out both on the inside and outside. In …
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As regards the sewer bricks, DIN 4051 differentiates between: -
All-side rectangular bricks – Shape K (Table left)
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Wedge-shaped bricks (Table right)
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Manhole bricks C
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Special dimensions (SF) (Round bricks for manhole bottom)
[DIN4051:2002] (Image: Wedge-shaped brick according to DIN 4051) (Table: Abbreviation, nominal size and permissible deviations from that the nominal size for bricks and brick veneers) (Table: Abbreviation, nominal size and permissible …
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(Image: Vitrified clay pipe - Icon) Pipes made of vitrified clay (formerly called clay pipes) count among the oldest pre-fabricated components in sewer systems. They are manufactured from suitable clays with the addition of fire clays and fired to the stage of sintering [FI-Stein96] [FVS78]. During the firing, a previously applied glazing mass permanently melts with the fragments for inner and, if required, outer glazing, which, contrary to all other …
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The standard cross section of pipes made of vitrified clay was and still is the circular cross section, which was mainly used for piping DN 100 to DN 600 so far.
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The graduations of the nominal sizes have remained almost unchanged up to the present. They increase by 25 mm steps up to DN 150, > DN 150 to DN 500 by 50 mm steps, > DN 500 to DN 800 by 100 mm steps and > DN 800 to DN 1400 by 200 mm steps. In the past, in-between sizes were manufactured …
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Vitrified clay pipes are is commonly used in drain and sewer systems because of their resistance to almost all domestic and industrial sewage, particularly the sulfuric acid that is generated by hydrogen sulfide. Only hydrofluoric acid and highly-concentrated caustic wastes are known to attack vitrified clay pipes.
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(Image: Reinforced steel pipe Icon) What is concrete? According to Schorn, concrete is a composite material comprising of natural or artificial aggregate particles that are coated by a binder (cement) in the liquid state (fresh concrete) and cemented together permanently in the hardened condition of the binder (solid concrete). [Schor83b] (Image: Production of concrete pipes)
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(Image: 50 Kg Cement bag) (Image: Aggregates) Materials used in the manufacture of precast concrete pipe consist of locally available aggregates and manufactured products. Each of the materials is covered by an EN, DIN or ASTM standard relative to its properties and methods of testing. The primary components of concrete are: -
Cement
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Fly Ash
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Water
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Aggregates
[FI-Lafarge]
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(Portland) Cement Portland cement, is a closely controlled chemical combination of calcium, silicon, aluminum, iron, and small amounts of other compounds, to which gypsum is added in the final grinding process to regulate the setting time of the concrete. Some of the raw materials used to manufacture cement are limestone, shells, and chalk or marl, combined with shale, clay, slate or blast furnace slag, silica sand, and iron ore [FI-Lafarge].
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Cage machines, mandrels and wire rollers are the three most common means of fabricating reinforcing cages in concrete pipe plants. A cage machine uses reels of high-strength, cold drawn steel wire. Using adjustable guides, it positions the longitudinal wires while wrapping the circumferential wires in a helix around the longitudinal. Intersections of the circumferential and the longitudinal wires are automatically resistance welded. The process produces …
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Today, according to the currently valid standards for gravity systems EN 1916 and DIN V 1201, it is distinguished among concrete-, reinforced concrete and steel fibre concrete pipes. [DINEN1916:2003] [DINV1201:2004] (Image: Reinforced concrete pipes with reference to [DIN4035] - Combi-Pipe [Image: S&P GmbH]) (Image: Reinforced concrete pipes with reference to [DIN4035] - Arch profile type 2 [Image: S&P GmbH]) (Image: Reinforced concrete pipes with …
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The differentiation of the term with reference to the design of pipes as concrete pipes, steel fibre concrete pipes and reinforced concrete pipes is included in EN 1916: (Image: Concrete pipe) A concrete pipe is a pipe made of concrete that is not equipped with a structural steel reinforcement or a reinforcement of steel fibres [DINEN1916:2003]. (Image: Reinforced concrete pipe) A reinforced concrete pipe is a pipe made of concrete that is structurally …
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There are two methods of precast concrete production employed at Lafarge facilities across Western Canada; drycast and wetcast production. Dry Cast The dry cast method uses zero slump concrete and vibration to produce a dense, durable concrete. This process allows the product to be removed from the forms after the concrete has been consolidated. Concrete pipe, boxes and manhole products are manufacture with this method. Wet Cast Wet casting of concrete …
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The European Standard EN 1916 is valid for pipes and fittings made of concrete, steel fibre concrete and reinforced concrete and distinguishes two different types of pipes and fittings. Only pipes of type 2 comply with the German quality standard for drains and sewers. [DINEN1916:2003] Type 1 for surface water drains and sewers with a degree of resistance against attacks from the outside that complies with a “lowly aggressive” chemical environment (…
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According to the currently effective EN 1916 and DIN V 1201, the pipes are classified as illustrated in Table according to their type of: [DINEN1916:2003] [DINV1201:2004] (Table: Designation of different types of pipes, regarding design, cross sectional shapes and pipe joints)
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Since November 2004, the dimensions of concrete pipes with circular and ovoid cross sections have to comply with DIN V 1201 in Germany [DINV1201:2004]. (Table: Concrete pipes with circular cross section with or without base according to DIN V 1201)
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Where is the application of reinforced concrete pipes suitable? Reinforced concrete pipes are particularly suitable for higher loads, such as those that act due to levels of earth burial or dynamic stresses caused by heavy traffic with low depths. Furthermore, these pipes are also used for special laying conditions, as e.g. in the trenchless installation methods [Stein03]. As a matter of principle, reinforced concrete pipes with circular cross section …
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In accordance with DWA-M 168, concrete pipes (made from "normal concrete") are considered to have sufficient corrosion resistance when: -
a permanent loading of inorganic and organic acids does not fall bellow a pH value 6.5.
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a temporary loading (up to one year for every ten years) with inorganic acids, with a pH of not less than 5.5 (for organic acids not less than pH = 6.0).
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a short-term loading (maximum of one hour per week) by inorganic and organic …
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The advantages of various materials are combined in concrete and reinforced concrete pipes with a corrosion protection applied directly during the production of the pipes for use in sewer systems with unavoidable and constantly "very strong" chemical aggressors according to DIN 4030 and DWA-M 168. These pipes are composed of two layers, the carrier layer on the outside and the corrosion protection layer (lining or coating) on the inside [Stein82b] […
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The latest development in the field of concrete- and reinforced concrete pipes is the “Optimised Pipe” for the nominal size range DN 500 to DN 1,200, which has an optimised outer contour with regard to structural and engineering factors. Pipe laying is facilitated because of the smooth bottom surface of the pipe and a gap in its centre. As the side walls are vertical, the difficult procedure to compact the spaces either side of the bottom half of …
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As the work space is no longer needed, which results in a reduction of the trench width, a considerably smaller quantity of excavated soil can be achieved in comparison to the “traditional” open cut method (for DN 700 about 25% less excavated soil), which saves carrying- and dumpsite capacities. The laying of optimised pipes is also eco-friendly with respect to natural resources of sand and gravel, as it requires no additional backfill material […
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Polymer concrete consists of a mixture of mineral, quartzite fillers in the minimally porous grading curve range according to DIN 1045, and reaction resin based on unsaturated polyester resins with properties according to DIN 16946 Part 2, Table 3. The polyester resin is very resistant to aggressive media (pH range 1.0 to 10) and the quartz aggregates are not chemically vulnerable. Since the material microstructure is free of capillaries, it does …
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The following list illustrates the material properties of polymerised concrete for the example of POLYCRETE® pipes: [FI-Meyer2015] (Table: Material properties of polymerised concrete for the example of POLYCRETE® pipes)
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Polymer concrete pipes are suitable for laying in the open cut- as well as trenchless method of construction. POLYCRETE® pipes for the open cut method are produced with circular cross section and bell socket from DN 300 to DN 1,000; with rebate joint from DN 1,200 to DN 2,000 as well as with ovoid cross section according to DIN 4263 in the nominal size range b/h of 400/600 to 1,400/2,100 [FI-Meyerb]. The bell socket has a rigidly inserted sealing medium; …
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Cast basalt is created by melting non-metallic components at 2000°C and by their subsequent crystallization. The final product is a three-phase system consisting of corundum, baddeleyite and glass phase with a very smooth surface. These minerals give the cast basalt a high compressive strength and especially great hardness (Mohs' hardness 8) and resistance to high temperatures, corrosion and abrasion. Cast basalt pipes are created in the centrifugal …
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