AASHTO T370-18 pdf free download
AASHTO T370-18 pdf free download.Measuring Adhesion of Hot-Poured Asphalt Crack Sealant Using Direct Adhesion Tester.
3. TERMINOLOGY
3.1 . Definitions:
3.1 .1. adhesion—the maximum force and energy required to separate hot-poured asphalt crack sealant from a standard substrate.
3.1 .2. hot-poured asphalt crack sealant—hot-poured modified asphaltic material used in pavement cracks and joints.
Note 1—Based on the references, hot-poured asphalt crack sealant is typically applied at a temperature of 160°C or above.
4. SUMMARY OF METHOD
4.1. Hot-poured asphalt crack sealant material is homogenized, following the procedure given in ASTM D5 167. For each test including four replicates, cut 40 g of sealant and heat to the manufacturer’s recommended pouring temperature. Sealant will be poured in the mold placed between the two half-cylindrical aluminum end pieces. The mold confines the sealant at the bottom and between the two aluminum end pieces at the sides.
5. SIGNIFICANCE AND USE
5.1. This procedure is designed to measure the adhesion of hot-poured asphalt crack sealant to aggregate.
5.2. Hot-poured asphalt crack sealant must be homogenized (ASTM D5167) before measuring the adhesion by this method.
6. APPARATUS
6.1. Direct Tension Test (D77) Device—The DTT system consists of two metal grips to hold the specimen, an environment chamber, a loading device, and a control and data acquisition system. The instrument must meet the requirements stated in T 314.
6.2. Test C’hamher—A calibrated circulated temperature control system having a temperature range from —4 to —40°C. The insulated test chamber shall be capable of maintaining the set temperature within ± 0.1°C.
6.3. Laboratoiy Oven—Any standard laboratory oven capable of producing and maintaining temperatures ranging up to 200°C ± 2°C.
6.4. Release Agent—A proper release agent to prevent the crack sealant from sticking to the mold. A silicon-based release agent is recommended.
6.5. Specimen Molds—Specimen molds shall be made of aluminum Al-6061 with No. 32 grid interface surfaces. The aluminum molds shall have pieces and dimensions as shown in Figure 1.
Note 2—Mold interface is manufactured to No. 32 grid. It is recommended to perform a visual examination of the interface surfaces before every test for dents, scratches, or bents. If the interface is visually deteriorated, replacement of the mold is recommended.
9. CALIBRATION AND STANDARDIZATION
9.1. Temperature of the ovens should be calibrated according to each user’s quality assurance program.
9.2. Temperature of the test chamber should be calibrated according to each user’s quality assurance program.
9.3. Calibrated Thermometers—Calibrated liquid-i n-glass thermometers to verify the temperature transducer having suitable range with subdivisions of 0.1°C. These thermometers shall be partial immersion thermometers with an ice point and shall be calibrated in accordance with ASTM E77 at least once per year. A suitable thermometer is designated 133C. An electronic thermometer of equal accuracy and resolution may be used.
10.9. Prepare a can of sealant by cutting 35 g of homogenized sealant for each set of four samples. 10.10. Place the can in the oven for 15 min. Remove can from the oven, stir the sealant thoroughly, and place it back in the oven for another 15 min. 10.11. Remove the can from the oven, stir the sealant thoroughly, and pour into all the assembled molds. Use four replicates for each sealant. Care should be taken in filling up the molds to prevent trapping any air bubbles in the sample. 10.12. Let samples set for 1 h at room temperature. 10.13. Trim the excessive sealant away with a hot spatula. Move spatula once over and parallel to the interface of the sample. Trimming direction shall not be changed during trimming. Use a well- heated spatula to prevent any shearing of the sealant. 10.14. Remove the grip piece and place the specimens in the cooling bath.AASHTO T370-18 pdf download.
