Four-point bending beam-based bituminous mixture interlaminar shear strength testing device

Abstract

The invention discloses a four-point bending beam-based bituminous mixture interlaminar shear strength testing device. A first support and a third support are arranged at the bottom of a loaded I-shaped beam, the first support is hinged to a first bending beam clamp, and the third support is hinged to a third bending beam clamp; a second support and a fourth support are arranged at the top of a base, the second support is hinged to a second bending beam clamp, and the fourth support is hinged to a fourth bending beam clamp. By regulating the positions of the bending beam clamps and the supports, the four-point bending beam-based bituminous mixture interlaminar shear strength testing device can guarantee that the vertical load applied onto a test piece corresponds to the designed length of a moment arm, and due to the interaction of vertical load and hinging, the interlaminar of a test piece only bears shearing load without the influence from bending moment stress, thus facilitating reasonable explanation and analysis on the interlaminar cementation situation of bituminous pavements in a pure shearing state, and simultaneously lightening the influence of rigidity of the bending beam clamp on testing results.

Description

technical field [0001] The invention relates to the technical field of road engineering, in particular to an asphalt mixture interlayer shear strength testing device based on a four-point bending beam method. Background technique [0002] Asphalt pavement is a multi-layer system structure composed of different structural layers. In the process of pavement structure design and construction, it is generally assumed that each structural layer is in a completely continuous state. Then, a large number of early pavement disease investigations show that the combination of asphalt pavement layers is one of the important factors affecting the service life of asphalt pavement, especially in large longitudinal slope road sections, small radius road sections, and acceleration and braking areas. The layer will generate a large horizontal load, and the shear stress generated between the layers of the pavement structure will be several times larger than that of the general road section. A...

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Problems solved by technology

However, the oblique shear test mostly uses a fixture with a fixed inclination angle, which produces a constant ratio of vertical force and horizontal force, which cannot simulate the change of compressive stress and shear stress produced by the actual pavement structure under the driving load with the depth of the pavement.

It can be seen that in the existing shear test method, there are both shear force and bending stress on the cross-section, which makes it difficult to reasonably explain and analyze the interlayer bonding of asphalt pavement under the pure shear state.

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