Platforms concrete

Methods like those dealt with in this section can be used on different structures, such as steel platforms, concrete platforms and pipelines. The best method to use depends on the type of structure. For pipelines, special problems exist and special adaptations of the methods are used [9.10]. 

Most turbomachinery is mounted on structural steel platforms sometimes referred to as base plates or skids. These platforms are then installed on a mass of concrete at the jobsite (either by direct grouting or mounting on sole plates) to become the machinery foundation. Platforms should always be considered as part of the foundation rather than as part of the machinery. 

Cement-based grouts will not bond well to the platform load-bearing surfaces. Over a period of time, lubricating oils will severely degrade both cement groups and concrete. This problem is further aggravated because... 

All platforms, regardless of the type of grout to be used, should be designed with oil drains. Epoxy grouts are recommended on platform installations because they provide an excellent oil barrier for the concrete below. Cement grouts should be used only for temporary installations. 

These materials are now widely used for coating both steel and concrete surfaces that are subject to a particularly aggressive environment (e.g. North Sea oil platforms). There is less validity for their use under normal atmospheric conditions since they are relatively expensive and tend to chalk on exposure to sunlight. However, their use as zinc phosphate, pretreatment or blast primers for blast-cleaned steel which is subsequently overcoated by any other paint system is an extremely valuable contribution to the painting of new steel work. 

By then I was halfway up Avery Hill, where the ack-ack guns I d never heard firing had long gone but the concrete platforms and bunkers remained, broken now, with twisted bones of rusting steel, and shadows and hollows, and stairs that led down to nowhere. 

Primary separation facilities process the produced fluids and gases into individual streams of gas, oil and water. These facilities are commonly referred to as Gas Oil Separation Plants (GOSP s), Central Processing Facilities (CPF) or if located offshore on drilling, production and quarters platforms (PDQ s). The offshore platform may either float on the sea or be supported on steel or concrete supports secured to the ocean floor, where it is capable of resisting waves, wind, and in Arctic regions ice flows. In some instances surplus oil tankers have been converted into offshore production and storage facilities. 

Platform carbonates Massive concretions of calcium carbonate in neritic sediments deposited by corals, corraUne algae and other organisms that deposit calcareous hard parts. 

FIG. 10-193 Cost ( 30 percent) of field-erected, domed, flat-bottom API 650 tanks, October 2005, includes concrete foundation and typical nozzles, ladders, and platforms. 1 gal = 0.003785 m. ... 

Fig. 7.15 The distribution of concrete cube tests for an oil production platform containing various admixtures.

The Hibernia offshore concrete platform on the Grand Banks off the coast of Newfoundland, Canada, is a 111 m structure and required about 165 000 m of superplaticized high-strength concrete. The typical mixture proportions and the properties of the concrete used for the skirt elements of the structure are shown in Table 7.18 [70]. The precast skirts are a series of reinforced concrete elements which were joined together to form continuous walls to support the base slab of the structure [69]. 

Hoff, G.C., Walum, R., Elimov, R. and Hisada, M. (1994). Production of High-Strength for Hibernia Offshore Concrete Platform, ACl SP-149, 37-62. 

The bunker entrance was built into the side of one of the more solid-looking loading platforms, a narrow trench leading down to a sturdy armour-plated door. The trench and the platform had been shored up with concrete and layered with satchels of energy-absorbent gel, a heavier-duty version of the padding in Sund s armour. Point-defence laser mines embedded in the concrete were clearly meant to be used on enemy aircraft, although the Doctor couldn t tell if any of them were currently active and in any case they were of no concern to anyone strolling up to knock on the door. 

Table 7.18 Hibernia offshore platform mixture proportions and strength test results of concrete for the precast skirt elements (Malhotra [69])... 

Figures 5.4 and 5.5 show typical elevation and plot plan section sketches of horizontal air-cooled exchangers. The essential components are one or more tube sections, called tube bundles, and one or more axial flow fans, all enclosed in a structural module made to anchor footings into concrete or to stand on an offshore platform. As shown, one fan may serve more than one tube bundle. A bay may be made up of multiple tube bundles and may also be served by one or more fans. Most important is the fact that one exchanger may be composed of any number of tube bundles. Tube bundles may be arranged in series or in parallel, just like shell/tube bundles.

Substances. A commercially available 193 nm resist based on a methacrylate platform was used. It was chosen due to its collapse behaviour at 75 nm dense lines. The surfactant under study is a commercially available cationic surfactant of high purity (> 99%). Surfactant solutions of various concentrations have been prepared by dilution with purified water. Since all concrete data of the surfactant are the subject of concealment, the surfactant concentration will be given in this paper on a relative scale. A relative concentration of 1 refers to the cmc which was determined from the surface tension of the solutions. 

---