Modulus tests

Compare flexural and tensile modulus testing methods. Why is it reasonable to say that both methods describe the rigidity of a material ... 

The classical means for following vulcanization by physical methods is to vulcanize a series of sheets for increasing time intervals and then measure the stress strain properties of each and plot the results as a function of vulcanization time. A modification of this test generally called a rapid modulus test is widely used in the industry as a production control test. A single sample taken from a production batch of compounded rubber is vulcanized at a high temperature and its tensile modulus is measured. Temperatures as high as 380°F are used to reduce the vulcanization test time to only a few minutes. Any modulus value deviating from a predetermined acceptance limit indicates that the batch is defective and is to be rejected. 

The variation of the damping factor (tan 5) with temperature was measured using a Polymer Laboratories Dynamic Mechanical Thermal Analyzer (DMTA). The measurements were performed on the siloxanfe-modified epoxies over a temperature range of — 150° to 200 °C at a heating rate of 5 °C per minute and a frequency of 1 Hz. The sample dimensions were the same as those used for flexural modulus test specimens. 

This is the same relationship, but different symbols have been used, as given in Chapter 8, Section 7.3 for torsional modulus tests and in Chapter... 

In the compression modulus test, the movement of the crosshead can be taken. Precautions also must be taken to prevent overrun of the crosshead by having stops installed to prevent damaging the load cell with an overrun. 

There are two alternative test procedures. The first requires the tensile and modulus tests to be carried out immediately after removal from the test solution, and the second after drying and stabilization of the sample. The results obtained, like all tensile results, are arbitrary and used for comparison purposes. The percentage changes in properties are normally reported. 

Specimen disintegrated in final resilient modulus test. 

Mechanical Characterization of Sulfur-Asphalt. The serviceable life of a pavement comes to an end when the distress it suffers from traffic and climatic stresses reduces significantly either the structural capacity or riding quality of the pavement below an acceptable minimum. Consequently, the material properties of most interest to pavement designers are those which permit the prediction of the various forms of distress—resilient modulus, fatigue, creep, time-temperature shift, rutting parameters, and thermal coefficient of expansion. These material properties are determined from resilient modulus tests, flexure fatigue tests, creep tests, permanent deformation tests, and thermal expansion tests. 

Fig 4. Typical arrangement for Fig 5. Quasi-static and dynamic modulus results for the dynamic modulus test. each of the three materials. 

TABLE 7.29 Flexural modulus test results (center-point load) with a Trex and GeoDeck samples and PTL... 

TABLE 7.31 Flexural modulus test results (third-point load) for Trex composite deck board... 

Table 7.37 shows lower values for flexural modulus determined by using 3-pt load compared to 4-pt load. On average, the difference is 9 + 7% in favor of third-point load compared to center-point load in terms of flexural modulus test values. The difference is very close to that (9 + 3%) for flexural strength values (see above). 

It should be re-emphasized that this analysis was only preliminary and based on assumed elastic properties of the sulfur-asphalt material. A more representative analysis using dynamic properties obtained from fatigue and resilient modulus tests is now in progress. 

The beams, fabricated in the material testing laboratory, having dimensions of 7.5 cm x 7.5 cm X 30 cm were tested for relative dynamic modulus in accordance with ASTM C 666-97. Three-inch cubes were sawn from each of the beams after the relative dynamic modulus test. The cubes were tested using procedures presented in ASTM C 116-90, Test Method for Compressive Strength of Concrete Using Portions of Beams Broken in Flexure. When the specimens were 28 days old, the freeze-thaw durability specimens were cured in lime-saturated water until testing was begun. 

Methods of Testing. ASTM tests for various concrete masonry units are available. These consist of compressive strength and sometimes per cent moisture and rupture modulus tests at a 28-day period. Compressive tests are often made by core-sampling actual construction work during early stages. To avoid waiting, 7-day tests are made and related to 28-day tests as follows ... 

For measuring compressive modulus, the. v// ratio should not be less than 0.08. while for other tests it should not be less than 0.4. The smaller ratio for the modulus test is permitted since the strain range required for the test is so small and hence the point of buckling is unlikely to be reached. As with other ISO test methods, preferred specimen sizes (Fig. 5) arc given, which in this case arc... 

Singh, R. K., Dev, C. (1988). Strength and modulus tests on jointed specimens of plaster of Paris. M. Tech Thesis, IIT-Delhi, India. 

P = proportional rut depth, determined in accordance to CEN EN 12697-22 (2007), large device. S = stiffness, determined by either the complex modulus test (trapezoidal or parallelepiped specimen) or the uniaxial tensile test (cylindrical or parallelepiped specimens), according to CEN EN 12697-26(2012). 

This chapter describes stiffness modulus tests under dynamic or static loading, wheeltracking tests and fatigue tests, and also provides the relevant nomographs still in use. 

The dynamic modulus test is conducted in accordance to the AASHTO T 342 (2011) or AASHTO TP 79 (2013) procedures. Both determine the dynamic modulus and phase angle over a range of temperatures and loading frequencies. 

Figure 7.10 Schematic representation of the dynamic modulus test, (a) Sample In testing device, (b) Details on the position of the LVDT (GL, gauge length d, specimen diameter). (From AASHTO T 342, Determining Dynamic Modulus of Hot Mix Asphalt [HMA], Washington, DC American Association of State Highway and Transportation Officials, 2011. With permission.)...

More details for the dynamic modulus test can be found in AASHTO T 342 (2011). 

Additionally, in the resilient modulus test, the loading time is approximately 0.1 s and the resting period is approximately 0.9 s, compared to approximately 1 s loading time and 2 s resting period used in the indirect tension test. 

In the resilient modulus test, the cylindrical specimens have a diameter of 101.6 3.8 mm or 152.4 9 mm and thickness ranging from 38.1 to 63.5 mm. The specimens are compacted in the laboratory with a gyratory compactor, or a Marshall compactor, or derived from field coring compacted asphalt layer(s). 

Permanent shear strain and complex shear modulus test using the SST... 

The permanent shear strain and complex shear modulus test, procedure B (at constant height), using the SST can be used to assess the performance of the bituminous mixture in wheel rutting, by using the shear strain parameter. 

Sampling and testing of soil materials are carried out according to established procedures. It is recommended to test all subgrade material within 600 mm of the planned elevation and in embankment areas to test the expected source of the fill material. Apart from the resilient modulus test (AASHTO T 307 2007 Asphalt Institute 1997), all other tests required... 

Nanoform Content Polymer Modulus Test Hardness Wear F.C. Ref. 

Tensile strength (tensile modulus) tests with or without preloading, according to specifications ASTM D638-03 [4], DIN EN ISO 527-1 [5] and DIN EN ISO 572-2 [6],... 

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