AASHTO T307-99 pdf free download

AASHTO T307-99 pdf free download.Determining the Resilient Modulus of Soils and Aggregate Materials.
3. TERMINOLOGY
3.1. untreated granular base and subbase materials—these include soil-aggregate mixtures and naturally occurring materials. No binding or stabilizing agent is used to prepare untreated granular base or subbase layers. These materials may be classified as either Type 1 or Type 2 as subsequently defined in Sections 3.3 and 3.4.
3.2. subgrade—subgrade soils are prepared and compacted before the placement of subbase and/or base layers. These materials may be classified as either Type I or Type 2 as subsequently defined in Sections 3.3 and 3.4.
3.3. Material Type 1—for the purposes of resilient modulus testing, Material Type I includes all untreated granular base and subbase material and all untreated subgrade soils that meet the criteria of less than 70 percent passing the 2.00-mm (No. 10) sieve and less than 20 percent passing the 75-rim (No. 200) sieve, and that have a plasticity index of 10 or less. Soils classified as Type 1 will be molded in a 1 50-mm diameter mold.
3.4. Material Type 2—for the purpose of resilient modulus testing, Material Type 2 includes all untreated granular base/subbase and untreated subgrade soils not meeting the criteria for material Type I given in Section 3.3. Thin-walled tube samples of untreated subgrade soils fall into this Type 2 category.
3.5. resilient modulus of untreated materials—the modulus of an untreated material is determined by repeated load triaxial compression tests on test specimens of the untreated material samples. Resilient modulus (M,.) is the ratio of the amplitude of the repeated axial stress to the amplitude of the resultant recoverable axial strain.
3.6. haversine-shaped load form—the required load pulse form. The load pulse is in the form (1 — cos 0)/2 as shown in Figure 1.
4. SUMMARY OF METHOD
4.1. A repeated axial cyclic stress of fixed magnitude, load duration (0.1 s), and cycle duration (1.0 to
3.1 s) is applied to a cylindrical test specimen. During testing, the specimen is subjected to a dynamic cyclic stress and a static-confining stress provided by means of a triaxial pressure chamber. The total resilient (recoverable) axial deformation response of the specimen is measured and used to calculate the resilient modulus.
5. SIGNIFICANCE AND USE
5.1. The resilient modulus test provides a basic relationship between stress and deformation of pavement materials for the structural analysis of layered pavement systems.
5.2. The resilient modulus test provides a means of characterizing pavement construction materials, including subgrade soils, under a variety of conditions (i.e., moisture, density) and stress states that simulate the conditions in a pavement subjected to moving wheel loads. Such material characterization may also be correlated with results from other tests such as T 88, T 89, T 90, T 100, andT233.
6.3.3.1. A positive contact between the vertical LVDTs and the surface on which the tips of the
transducers rest shall always be maintained during the test procedure. In addition, the two LVDTs shall be wired so that each transducer can be read and reviewed independently and the results
averaged for calculation purposes.
Note 3—Misalignment or dirt on the shaft of the transducer can cause the “sticking” of the shafts of the LVDT. The laboratory technician shall depress and release each LVDT prior to each test to assure that there is no sticking. An acceptable cleaner/lubricant (as specified by the manufacturer) shall be applied to the transducer shafts on a regular basis.AASHTO T307-99 pdf download.