AASHTO T 336-15 pdf free download

AASHTO T 336-15 pdf free download.Coefficient of Thermal Expansion of Hydraulic Cement Concrete.
4. SIGNIFICANCEAND USE
4.1. Measurement of the CTE permits assessment of the potential for length/volume change of concrete due to a uniform temperature change and of the potential deformation of a concrete structure due to a temperature gradient through the concrete. As an example, for pavement slabs on grade, uniform temperature change will affect the openings at joints and a temperature gradient through the thickness of these same slabs will produce curling of the slabs. The results of this test can be used to better estimate slab movement and stress development due to temperature change.
5. APPARATUS
5.1. concrete Saw—Capable of sawing the ends of a cylindrical specimen perpendicular to the axis and parallel to each other.
5.2. Balance—A scale or balance having a capacity of 20 kg (44 ib) and an accurateness of 0.1 percent over its range.
5.3. Caliper—Comparator or other suitable device to measure the specimen length to the nearest
0.1 mm (0.004 in.).
5.4. Calibration Specimeii—A calibration specimen with a known coefficient of thermal expansion shall be used to determine the correction factor of the equipment. The specimen shall be composed of a material that is essentially linearly elastic, noncorroding, nonoxidizing, nonporous, and nonmagnetic, and it shall have a known thermal coefficient of expansion not to exceed 20 micro strainl°C determined over the temperature range of 10 to 50°C (50 to 122°F) (see Note 1). Option 1: An ISO 9001 or equivalent laboratory should determine the CTE of the calibration specimen according to ASTM E228 or ASTM E289 within the temperature range of 10 to 50°C (50 to 122°F) and provide a certificate of the CTE value (see Note 2). Option 2: Manufacturer determines the CTE of the calibration specimen determined from a properly calibrated CTE device meeting T 336 requirements. The CTE device used to determine the CTE of calibration specimens must be calibrated and verified using specimens that have previously been determined following Option 1. The CTE value and date tested shall be marked on the calibration specimen. The diameter of the calibration specimen should be large enough to firmly rest on the semispherical support buttons of the frame described in Section 5.7 and the length should be 177.8 ± 2.5 mm (7.0 ± 0.1 in.) (see Note 3).
Note 1—Grade 304 stainless steel, titanium, and nickel are suitable materials.
Note 2—Testing of a full-height specimen is preferred. If coupons are used to determine the CTE of the calibration specimen, care must be taken to ensure that the longitudinal direction of the coupon is in the same direction as the calibration specimen it represents. The coupons shall be obtained adjacent to the location where the full-height specimen was obtained.
Note 3—Different-length concrete specimens can be tested provided the frame is recalibrated and verified with specimens with lengths that are ±2.54 mm (±0.1 in.) of the concrete specimen to be tested.
5.5. Length change Measurement Device—The sample length change shall be measured using any suitable apparatus that has sufficient resolution and gives reproducible results. In this standard, the use of a linear variable differential transducer (LVDT) is described. The LVDT with excitation source and digital readout shall have a minimum resolution of 0.000125 mm (0.000005 in.) and a range suitable for the test. The semi-spherical contact tip (at the point of contact between the measuring device and the specimen) must be firmly attached to the length change measuring device to prevent loosening during a test (see Note 4).
Note 4 Submersible and nonsubmersible LVDTs are suitable.AASHTO T 336-15 pdf download.