Test method for porosity of asphalt mixture, and apparatus thereof

Abstract

The present invention relates to a test method for porosity of an asphalt mixture, and an apparatus thereof. With the present invention, the volumes of the pore with an opening and the pore with a semi-opening can be determined. The test apparatus mainly comprises a sealed container, a pressurization device of the sealed container, a hydraulic cylinder, a water pump and a flow control valve. The sealed container is provided with a pressurization piston. A piston rod of the hydraulic cylinder is connected with the pressurization piston arranged inside the sealed container. The flow control valve is connected between a water inlet of the sealed container and the water pump. The test method comprises that: a specimen is sealed with a thin film, and is placed in the sealed container; with thehydraulic cylinder, the piston inside the container is pushed, such that the air pressure in the container is increased to more than two standard atmospheric pressures; water is slowly injected to the container until the height of the water is the preset height, and the water injecting amount is recorded as L1; the specimen is taken, and the thin film is removed, then the specimen is placed in the container again; under the same air pressure condition, water is slowly injected in the container, and the water injecting amount is recorded as L2; the difference between the two water injecting amount is the amount that the water enters the inner pores of the specimen, and the porosity of the specimen can be calculated, wherein the difference is calculated by the following formula, L2-L1.

Description

technical field [0001] The invention belongs to the field of solid porosity testing, in particular to a testing method and device for the porosity of asphalt mixture. Background technique [0002] The porosity of asphalt mixture is an important evaluation index for the performance of pavement structure, especially for drainage asphalt pavement structure, the porosity directly determines the drainage and noise reduction effect of the pavement. In highway engineering asphalt and asphalt mixture test regulations (JTJ 052-2000), the test methods for testing relevant indicators using the water absorption performance of asphalt mixture include surface dry method and wax seal method. Calculate the pore size and volume parameters by using the difference between the weight of the part in air and the weight in water. [0003] The pores in the asphalt mixture structure include open pores, closed pores and semi-open pores. Open pores refer to two or more openings communicating with the...

AI Technical Summary

Problems solved by technology

For open pores, water can easily enter under normal pressure; for closed pores, no matter what method is used, water is difficult to enter; for semi-open pores, the air in the pores cannot be discharged immediately under normal pressure

Therefore, when measuring the porosity in the asphalt mixture structure with the existing method, it is easy to mistake the semi-open pores for the closed pores, and the measured results cannot truly reflect the porosity in the asphalt mixture structure, while the open and semi-open pores have a significant impact on the structure of the asphalt mixture. Water permeability, strength, asphalt oxidizability and other properties of asphalt mixture structure have important influence

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