Panel specimens

Pararosaniline was used for formaldehyde analysis, rather than chromotropic acid, using the same panel specimens as those used in the test whose results are reported directly above. 

Thin section panel results. The results of the thin section panel evaluation are presented Table 3. Trial mixes PINR and PINT offered very similar workability and mesh bond characteristics. The difference in mesh concrete bond can be seen in Fig. 5 which compares the bond between the mesh and mix PINT with that of the control mix CL. The trial mixes PINR and PlNl gave the best all round balance between workability and finish. As can be seen from Table 3, the trial mix P2NL may suit an extrusion process very well. This possibility was identified during the construction of the thin section panel specimens and will require further research. During the application of the mix mortar it was noticed that additional trowel pressure gave the mortar a putty like appearance which also served to improve the surface finishes of the manufactured specimen. 

Steel) response levels. Accuracy of the presented modeling approaches were demonstrated via comparismi of the model predictions with test results conducted on reinforced concrete wall, column, and panel specimens. The modeling approaches presented are believed to be a significant improvement towards reaUstic representation of the nonlinear response of reinforced concrete walls and columns. ImplementatiOTi of the model formulations into a computational structural analysis platform will allow improved seismic response predictions for existing buildings, for obtaining more reliable performance assessment results and arriving at more informed decisions oti rehabilitation. 

Specimens may be of ciny practical size or shape. However, it is advisable not to use too small a specimen since visual examination is the key evaluation method. It is recommended that flat specimens at least 50 mm by 75 mm in size and full section thickness be used with the specimen length oriented in the direction of principal deformation of the mill product. Larger sized panel specimens are desirable for salt spray testing or outdoor exposures. 

Figure 12.57 TEM images of (SI-t-COONa)/Cloisite 30B nanocomposite at 70 and 150 °C (upper panel), and TEM images of (SI-t-COOH)/Cloisite 30B nanocomposite at 70 and 150 °C (lower panel). Specimens were first annealed at 70 °C for 24 h or at 150 for 6 h and then stained with osmium tetroxide, followed by a rapid quench in ice water. (Reprinted from Zha et al.. Macromolecules 38 8418. Copyright 2005, with permission from the American Chemical Society.)...

E.S. Bernard, Correlations in the behaviour of fibre reinforced shotcrete beam and panel specimens . Mater. Struct (RiLEM). 35, 2002,156-164. 

In the case of a panel painting, a small sample of the wooden support can be removed, from which a microscopic specimen can be prepared in order to identify the wood used for the panel. 

The reproducibility of test results between labs using the neutral salt spray tests has not been consistent, but the repeatability, within one lab, is better, and the test has value in comparing variations in coating systems. Correlation of hours of exposure in the salt spray test to actual performance of the plated part in service, even in marine atmospheres, is not consistent and usually avoided. A classic example is that cadmium deposits outlast zinc deposits on steel in salt spray tests and clean marine atmospheres, yet zinc outlasts cadmium when exposed to real, industrial atmospheres, because of the presence of sulfur-bearing corrodents in industrial environments. An important variable in salt spray testing is the position of the surface to be tested. Whereas the surface of test panels is specified to be 15—30° from the vertical (40), when salt spray testing chromated zinc-plated specimens, this range has appeared excessive (41). 

It is significant that most of the data from which a remarkable uniformity of attack is deduced are derived from small isolated panels. This is the most convenient form of specimen for measurements of corrosion rates by loss of weight but it eliminates the important effect of galvanic currents passing between remote parts of a large structure. It is believed that the experience of civil engineers and other users would not support the conclusion suggested by panel tests that corrosion is no faster in tropical than in temperate waters. 

A fairly direct way of observing galvanic effects, which also permits changes in mechanical properties to be measured, involves the preparation of a composite specimen formed by attaching a strip, or strips, of one metal to a panel of another one. Tensile test specimens that include the areas of galvanic action can be cut from these panels after exposure, as shown in Fig. 19.30. 

A modification of the specimen shown in Fig. 19.30 may be made simply by lapping a panel of one material over a panel of another one. The greatest effects may be observed when such panels are exposed with the laps facing up so as to favour retention of corrosive liquids along the line of contact. To permit observations of secondary effects of corrosion products, or exhaustion of corrosive constituents, the relative positions of the dissimilar metals should be changed from top to bottom in duplicate test assemblies. 

Specimens will normally be flat panels, large enough to avoid any effects caused by nearby edges of the specimen. Edges and backs are usually coated... 

Field and Plant Tests Field exposure of test panels offers the benefit of a high degree of control over surface preparation and application. Moreover, through standardised exposure conditions, broader comparisons between both paint systems and locations are possible. More importantly, since replicates may be removed and laboratory tested periodically, changes in properties can be followed in considerable detail. At least four replicates should be examined for each exposure period to minimise the effects of atypical specimens. 

Tinplate and Solder. The tests were carried out to determine the effect of low temperature irradiation on the metallurgical properties of the tinpalte, solder, and soldered lap joints. Two types of tinplate were used 43 kg (95 lb), Type MR-TU and 43 kg (95 lb), Type MR-T2, both coated with No. 25 electrolytic tinplate. The test specimens were 20 X 20 cm panels. 

Films, for both mechanical and spectroscopy studies, were affixed to the specimen panels of the weatherometer. Upon completion of the UV exposure, which occurred at 37°C 1°C in the presence of air, the films were removed and kept at room temperature in the dark for at least 24 hours in order to remove any volatile oxidation products. 

Figure 2. The Radiant Panel Test was designed to measure both critical ignition energy and rate of heat release. A sample is mounted facing a controlled heat flux but at a 3CP angle to it such that the upper part of the specimen is more severely exposed. Since irradiance decreases down the specimen, the time progress of ignition down the specimen serves to measure central ignition energy. Thermocouples in the stack above the specimen serve as a measure of heat release rate.

Experimental results are presented that show that high doses of electron radiation combined with thermal cycling can significantly change the mechanical and physical properties of graphite fiber-reinforced polymer-matrix composites. Polymeric materials examined have included 121 °C and 177°C cure epoxies, polyimide, amorphous thermoplastic, and semicrystalline thermoplastics. Composite panels fabricated and tested included four-ply unidirectional, four-ply [0,90, 90,0] and eight-ply quasi-isotropic [0/ 45/90]s. Test specimens with fiber orientations of [10] and [45] were cut from the unidirectional panels to determine shear properties. Mechanical and physical property tests were conducted at cold (-157°C), room (24°C) and elevated (121°C) temperatures. 

Mechanical Property Testing. Mechanical tests were performed on both unirradiated and irradiated materials at -157°C, 24°C, and 121°C. Specimens were kept dry prior to testing in an environmental chamber mounted in a tensile testing machine. Tensile test specimens of [0]4, [10]4, [45]4, and [90]4 laminates were cut from 4-ply composite panels. All specimens were straight-sided coupons. For tension and shear tests the length/width aspect ratio was 8. For the compression tests the aspect ratio was 0.25 and the unsupported length was 0.64 cm. The [0]4 laminates were used to measure the ultimate tension and compression strength, Xit the axial... 

An industrial standard method has been developed to test the lightfastness of polymers in accelerated test equipment [103]. The apparatus consists of a quartz-xenon tube with a special optical filter between the light source and the specimen to produce light that resembles window glass-filtered daylight [104], Samples are mounted at a specific distance from the arc and are supported on a frame which revolves around the arc 1 to 5 times per minute for uniform exposure. A blower unit in the base provides a flow of air which makes it possible to maintain a black panel temperature of 45°C, measured by a black panel thermometer which is positioned at level with the samples. A black panel unit consists of a bimetallic thermometer mounted on a steel frame. Both faces of the frame plate and also the stem of the thermometer are coated with a heat-resistant glossy black enamel. The relative humidity level in the exposure cabinet is closely controlled. 

The black panel temperature is measured with a thermocouple mounted on a flat black painted panel which is placed on the sample rack of the Weather-Ometer. As such, the temperature registered is meant to indicate a maximum temperature of the specimens under the same irradiation. 

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