ASTM D1195:21 pdf free download – Standard Test Method for Repetitive Static Plate Tests of Soils and Flexible Pavement Components for Use in Evaluation and Design of Airport and Highway Pavements.
6.3 This subsection describes the digital system using a displacement transducer and load cell to capture the data during the test procedure. The description below is in compliance with DIN 18134.
6.3.1 Plate Loading Apparatus. consisting of a loading plate. an adjustable spirit level, and a loading system with hydraulic pump and jack assembly with high-pressure hose.
6.3.2 Dcviccs for measuring thc load applicd and the settlement of the loading plate at right angles to the loaded surface, and means of calculating the strain modulus.
6.3.3 The reaction loading system shall produce a reaction load which is at least 10 kN greater than the maximum test load required. ft may be a loaded truck or roller or any other object of sufficient mass.
6.3.4 Loading plates shall be made of Specilication A5721 A572M Or. 50 (EN 10025 grade S355J0) steel or equivalent material with the same stiffness and hardness. They shall be machined so as to have the flatness and roughness tolerances in accordance with Figs. 2 and 3. The loading plate shall have two handles (see Fig. 2).
6.3.5 Loading plates with a diameter of 300 mm shall have a minimum thickness of 25 mm.
6.3.6 Loading plates with a diameter of 6(X) mm or 762 mm shall have a minimum thickness of 20 mm and be provided with equally spaced stitkners with even upper faces parallel to the plate bottom face to allow the 300-mm plate to be placed on top of it. Centering pins, and also clamps, if necessary. shall be provided to hold the upper plate in position (see Fig. 3).
6.3.7 Loading System:
6.3.7.1 The loading system consists of a hydraulic pump connected to a hydraulic jack via a high-pressure hose with a minimum length of 2 m. The system shall be capable ol applying and releasing the load in stages.
6.3.7.2 Uor the pressure to be properly applied, the hydraulic jack shall be hinged on both sides and secured against tilting. The pressure piston shall act through at least 150 mm.
6.3.7.3 The height of the plate loading apparatus during operation should not cxcccd 600 mm. In order to compcnsatc for differences in the heights of the vehicles used as reaction loads, elements shall be provided that allow the initial length of thc hydraulic jack to be increased to at cast 1.000 mm. Suitable means shall be provided to prevent buckling of these elements.
6.3.8.1 A mechanical or electrical force transducer shall be lutted between the loading plate and the hydraulic jack. It shall measure the load on the plate with a maximum permissible error of I of the maximum test load.
6.3.8.2 The stress shall be indicated at a resolution of at least 0.001 MPa for a 300-mm loading plate and at least 0.000l MPa for 600-mm and 762-mm loading plates.
6.3.8.3 The resolution of the force-measuring system shall be equivalent to that of the force transducer.