BHMA A156-21:2019 pdf download.STANDARD FOR THRESHOLDS
4.1.1 Test Fixture Provide a loading device having a flat bed large enough to accept a threshold test specimen and that will not deflect when the specified load is applied. The load shall be measured with a dial or digital gage having a combined calibration and reading accuracy within 2%. All threshold measurements are to be taken with a gage accurate within ± 001 in.(.025mm). Use a 1/4 in. (6.3 mm) thick cold rolled steel plate 3/4 in. (19 mm) wide and 3 in.(76.2 mm) long connected to a 3/4 in. (19 mm) diameter steel rod with a maximum length of 6 in. (152mm) for transferring the load to the threshold surface. The fixture shown in the Figure below shall be used to apply the load to the specimen surface, and with support on one side only to prevent the specimen from sliding. The swivel mount is intended to maintain full plate contact on sloping thresholds.
4.1.2 Procedure Place a 12 in. (305mm) long threshold specimen on the flat bed. The before and after measurements shall be taken at the same position. This single position shall be at the center of the length of the specimen and at the center of the widest span between two adjacent support points, including those which contact the bed under load. Orient the steel plate centered with the 3 in. (76mm) dimension in the direction of the threshold length. Gradually apply a downward compressive load within 20 seconds±5 seconds until a reading of 1000 lbf (4448 N) is reached. After 15 minutes±30 seconds at the specified load, remove the load and re- measure the height of the specimen. Permanent set shall not exceed 0.040 in. (1.02mm).
4.2 Threshold Compressive Load Test for Heavy Duty Thresholds (10,000 lbf load)
4.2.1 Test Fixture Provide a loading device having a flat bed large enough to accept a threshold test specimen and that will not deflect when the specified load is applied. The load shall be measured with a dial or digital gage having a combined calibration and reading accuracy within 2%. All threshold measurements are to be taken with a gage accurate within ±.001 in.(.025mm). Use a 3 in. (76.2 mm) thick cold rolled steel plate 1 /2 in. (38.1 mm) wide and 3 in.(76.2 mm) long connected toa 1 / 2 in. (38.1 mm) diameter steel rod with a maximum length of 6 in. (152 mm) for transferring the load to the threshold surface. The fixture shall be configured to apply the load to the specimen surface, and with support on one side only to prevent the specimen from sliding. The swivel mount is intended to maintain full plate contact on sloping
thresholds.BHMA A156-21 pdf download.