Road test laboratory measurement

Correlation between Road Test Data and Laboratory Measurements.715... 

CORRELATION BETWEEN ROAD TEST DATA AND LABORATORY MEASUREMENTS... 

The basis of comparison is Similar log a v values and track surface stmctures for laboratory and road test conditions. As discussed under Section 26.3.6 side force measurements at constant slip angle and load over a suitable range of speeds and temperatures form a very good basis for comparison with road data. 

FIGURE 26.40 Correlation coefficient between road test ratings on a wet concrete track and laboratory measurements on a wet blunt Alumina 180 disk. Left as function of log a- v and right as function of log a-rv and log V. 

Figure 26.42 compares the correlation coefficient between a road test on wet concrete and the laboratory side force measurements of the six compounds of Table 26.2 on blunt, wet Alumina 180 (a) with a log oxv-log v evaluation and (b) with a temperature-log v evaluation. It appears that the... 

FIGURE 26.42 Comparison of the correlation coefficients between laboratory side force measurements with the six compounds of Table 26.2 on wet, blunt Alumina 180 and a concrete road test track as function of log ajv and log v (left) with function of temperature and log v (right). 

In fact, when using a low-oil SBR recipe in the laboratory and measuring abrasion loss of the same blacks used in the road test, we found excellent correlation between abrasion loss and treadwear. 

It is important to know the sound transmission loss of walls and floors in order to be able to compare different constructions, to calculate acoustic privacy between apartments or noise levels from outdoor sources such as road traffic, and to engineer optimum solutions to noise control problems. Laboratory measurements can be made for many different types of partitions, but it is impractical to test every possible design, and so it is necessary to have reliable methods for predicting the sound transmission loss of typical building constructions. 

Basically, a road traction test differs from a laboratory test only in that the temperature in the contact area is allowed to rise and is not really measurable, whilst in the laboratory the speed is kept so low that the temperamre rise may be neglected. 

In Part 1 [1] we described a protocol for the evaluation of measurement uncertainty from validation studies such as precision, trueness and ruggedness testing. In this paper we illustrate the application of the protocol to a method developed for the determination of the dyes Cl solvent red 24 and Cl solvent yellow 124, and the chemical marker quinizarin (1,4-dihydroxyanthra-quinone) in road fuel. The analysis of road fuel samples suspected of containing rebated kerosene or rebated gas oil is required as the use of rebated fuels as road fuels or extenders to road fuels is illegal. To prevent illegal use of rebated fuels, HM Customs and Excise require them to be marked. This is achieved by adding solvent red 24, solvent yellow 124 and quinizarin to the fuel. A method for the quantitation of the markers was developed in this laboratory [2]. Over a period of time the method had been adapted to improve its performance and now required re-validation and an uncertainty estimate. This paper describes the experiments under-... 

Fig. 4.14. The road-map for the isochronous measurement of stability shows when the bottles have to be taken out from the initial storage temperature of -20 to be set at the increased destabilisation temperature. At the end of the production, 100 bottles are set aside at -20 °C (could be lower e.g. -80 C). After the homogeneity study (month 0), 5 bottles are stored at each of the studied temperatures. Here a very extensive temperature study is performed (+4, +20, +40, +80 °C), usually materials are tested at room temperature and +40 °C unless feasibility studies have revealed risk of instability. After 6,9 and 11 months each time 5 more bottles are added at each storage temperature. All bottles (100 in total) are analysed together. Such a study can be planned over three years instead of 12 months. When the analyses do not reveal instability a new study can be started in the same conditions taking as time 0 the end of the measurements of the first study. The disadvantage of such an approach is that the study reveals a possible instability only at the end. Therefore, it is hardly usable for the development and first production of a CRM. It is an advantageous approach for the monitoring of stability by the suppliers as it allows an easy planning of the laboratory work if several materials have to be followed [49].

This method measures the elastic stiffness of bituminous mixtures by the indirect tensile test, using cylindrical specimens of various diameters and thickness, manufactured in the laboratory or cored from a road bituminous layer. The form of loading is pulse loading (see Figure 7.1a), and the test is carried out under controlled strain conditions. This test is perhaps the most popular of all other tests for stiffness determination. 

This method measures the stiffness of bituminous mixtures by the cyclic indirect tensile test, using cylindrical specimens, manufactured in the laboratory or cored from a road layer. 

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