Precast Concrete Pipe and Box Culvert Equipment Calibration To Trust What We Measure And To Maintain Consistency

Calibration of Testing / Inspection Equipment for RCP 6.2.7.6 Calibration of Equipment Check all quality control testing equipment and calibrate them, as required in ASTM C 497. A reputable licensed testing laboratory shall calibrate all jacks and gauges for the three-edge-bearing test equipment at least once every twelve-month period. Source: FDOT Materials Manual, Section 6.2, Vol. II

Calibration of Testing / Inspection Equipment for Precast RCB 6.3.7.6 Calibration of Equipment Check or calibrate all quality control testing equipment such as the batching scales, compressive strength testing machines, portable weighing scales, air meters, density buckets, and temperature recording devices for compliance with the applicable test methods. Source: FDOT Materials Manual, Section 6.3, Volume II

Equipment Calibration Three Edge Bearing (3EB) Rack Compressive Strength Tester Hydrostatic Pressure Gauge Water Meter Batch Plant Scales Laboratory Scales Admixture Dispenser Joint Gauging Equipment Temperature Gauge (Thermometer) Micrometers

3EB Test Equipment

What is the history of the 0.01 inch crack in RCP? ! What is the history of the 0.01 inch crack in RCP? In 1920s/1930s, everyone had their own idea of a “crack” when performing the 3EB test. There was no standard of d-load crack measurement. A 0.01-inch thick feeler gauge was decided to be the standard by which the d-load crack width would be defined. It is an arbitrary standard of measurement born out of the need for consistency and practical application.

3EB Calibration 4.4 Calibration—The loading device shall be one which shall provide an accuracy of  2 % at the specified test loads. A calibration curve shall be used. The machines used for performing the three-edge-bearing tests shall be verified in accordance with Practices E 4. Source: ASTM C 497 Standard Test Methods for Concrete Pipe, Manhole Sections, or Tile

Weighing Scales for Absorption 7.4.5 Scale Sensitivity—Weigh specimens weighing less than 1 kg to an accuracy of 0.10 % of the specimen mass. Weigh specimens weighing more than 1 kg to an accuracy of 1g. Source: ASTM C 497 Standard Test Methods for Concrete Pipe, Manhole Sections, or Tile

Hydrostatic Joint Test Pressure Gauge Calibration 16.3 Apparatus: 16.3.1 Hydrostatic pressure tests on joints shall be made on an assembly of two sections of pipe, properly connected in accordance with the joint design. The hydrostatic pressure shall be measured with a gage or manometer accurate to  5 % of the test pressure. 16.3.2 The testing machine shall be of any type that has sufficient capacity to apply the required test load, that is in addition to the weight of the pipe filled with water, or a suitable dead load shall be applied. Source: ASTM C 497 Standard Test Methods for Concrete Pipe, Manhole Sections, or Tile

Compressive Strength Calibration ASTM C 39 Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens Verify calibration: At least annually, not to exceed 13 months Upon installation or relocation After making repairs or adjustments… Whenever accuracy of loads is suspect Paragraph 5 (Apparatus) 5.3 Load Indication

Thermometer Calibration ASTM C 1064 Standard Test Method for Temperature of Freshly Mixed Hydraulic-Cement Concrete Calibrate using two thermometers Calibrate at two temperatures At least 30 degrees difference between tests

Calibration Summary Consistency in Measurements Applies to all Test Instruments / Devices Check FDOT and ASTM Specs ASTM Test Method Specification Allowable Limits Frequency of Calibration Method of Calibration