Technology

Roll materials are mainly melted with the help of liquefied gas or liquid fuel hand burners. Mobile heaters are also used to heat the whole width of the roll to be pasted. They consist of a row of heaters fastened to a special frame on atwo-wheeled chassis. Hand rollers press the coils. Foreign producers (German Linnhoff Maschinenbau GmbH, for instance) use certain machines to apply rolled bitumen dampproofing. They are manufactured in 2 configurations: self-propelled and manually-operated. They can lay up to 80 meters at 2-4 m/min. The VBS self-propelled machine is fixed on a carriage frame fitted with a tandem-axle chassis and control unit. It allows automated monitoring of operations. An electric motor feeds a two-wheel rear axle drive, which is powered by a diesel engine. The front axle turning control is mechanical. 7 propane burners heat the waterproofing bitumen coil. As the machine moves, the roll is reeled out and heated, then pressed onto the covering by two rows of pressure rollers to be protected. A special control unit, drive and mechanized operations boost the performance, quality and reliability of the protective covering as well as automatize the process. The equipment of this kind was already used in St. Petersburg when constructing a cable-braced bridge. To implement this technology “TehnoNikol” company has created rolled-strip material Tehnoelastmost («Òåõíîýëàñòìîñò Ñ Ãèãàíò») with 50 m long rolls to be applied on any road covering; it is compatible with all asphalt concrete types. The technology of roll sealing with infrared bitumen heating units has been developed recently and is efficiently used. Infrared rays heat the under surface of the rolled material simultaneously with the upper surface of the foundation up to 140-160 °Ñ without damaging the external surface of the material. Sealing material sheet is tightly pressed onto the basement with a multisectional roll. Surface layers melt at 0.5-0.8 mm depth and form a roll of melted bitumen about 10 mm thick. It fills up the rough basement and enables the whole length of the roll to be adhered and have a monolith coating. The layers of sealing material are adhered at a molecular level. The advantages of this technology are high quality operation, no open flame, high productivity. It is environment-friendly and fire-safe. Another sealing technique applies on concrete and metal surfaces without flame is splashing hot and cold dampproof mastics and bitumen and latex emulsions. They are medium and highly viscous liquids in initial state. The liquid is applied mainly through airless spraying technique. Pneumatic spraying facilities are quite seldom applied. When applying sealing material by airless spraying the liquid is ejected under high pressure through a nozzle at high speed into air and turns into a jet of sputtered particles, which then settle on the surface. The formed coating has high adhesion to the basement. In comparison with pneumatic technique airless spraying by high pressure units saves applied material because losses due to fogging are considerably cut down. High jet speed boosts productivity and solvents can be decreased or excluded altogether. The principal construction arrangement of airless spraying units manufactured by different companies is similar. It involves a petrol motor (optionally), a hydraulic driven piston pump or inclined Archimedean screw pump, hoses, an injector fitted with a nozzle. Most units admit two or more atomizer pistols. Nozzles can be easily replaced and the pump, atomizer and supply hoses can be cleaned. Most modern units used for application of liquid sealing products are operated through an electronic module by one operator. Some models are fitted with a remote control unit. To start the unit it is necessary to set up spraying pressure and sealing products (one- or two-component) flow rate, heating temperature in case of hot mastics splashing.The display unit shows spray parameters and the amount of consumed material. The electronic module allows diagnostics of the whole system and the report about the performed operations. When choosing a unit for certain purposes it is essential to take into account its engineering data shown in the chart, as well as special technical performance capabilities which will be discuss below. Among leading producers of this kind of equipment we can name GRACO/GUSMER (USA); J. Wagner GmbH (Germany),including Titan Tool Inc.(USA ); Larius è Sinaer s.r.l. (Italy); “RASTROclosed company” («ÐÀÑÒÐλ). The most powerful and productive unit in the line is GH-ROOF RIGGSby GRACO/GUSMER, powered by a petrol motor with electric starter and hydraulically driven high pressure piston pump. It is designated for splashing highly viscous sealing products.The remarkable feature of the unit is that replaceable bottom pumps of any modifications can be quickly installed on it. The same unit can apply materials with different viscosity by replacing only one element. To spray viscous clearcole, latex, bitumen mastics, emulsions GRACO’s GMax Honda, ULTRA® MAX II è MARK V series units with hydraulic high pressure pumps are used. MARK V unit is fitted with two innovative SMARTCONTROL  system of operating parameters and AUTOCLEAN II system of pump, injector and hoses self-cleaning. To apply the above mentioned materials HeavyCoat (ÍÑ) piston pumps with indirect hydraulic drive by Wagner and EL NEW 16000 pumps by Sinaer are used. This system has the following advantages: a longer and slower piston stroke compared to direct drive pumps, and high wearing capacity and as a result longer life cycle. Materials of any viscosity consistence are pumped easily due to high suction capacity. It outstrips other units of the same capacity and enables application of more viscous products on the surface (including orthotropic slabs) at a shorter time than. Work surfaces of cylinders and piston rods of HeavyCoat è EL NEW 16000 units have wearproofhard chromium and are proof to hostile environment  and abrasion. Manufacturers use this protection in most cases. The HeavyCoat (ÍÑ) series pumps are fitted with a Wagner patented SSP system included in the base configuration of the ÍÑ 940 and ÍÑ 960 units. It makes the pump fill incessantly with the necessary amount of material. The pump operates without pulsing and irregularity. The units also have a SwingCart function to lift the suction element in upward position convenient for material intake from buckets and containers and in transport. The HeavyCoat units design allows electric motor to be changed with an optional Honda petrol motor in minutes and vice versa. It ensures energy-independence of the units and their application on construction sites where no power supply is available.Larius s.r.l. (Italy) has designed an unorthodox unit LARIUS VIKING to perform large volumes of sealing works. Its highlight is a pump with two suction systems and high pressure hoses that allow simultaneous application of two composites. s.r.l., DRIZORO S.A

Inclined Archimedean screw pumps produced by an Italian DRIZORO S.A. company are effectively used for the application of protective covering, bitumen emulsions and ground mixes.