Method for determining void saturation of large-void asphalt mixture in seepage state

Abstract

The invention relates to a method for determining void saturation of a large-void asphalt mixture in a seepage state. The method comprises the following steps: according to the volume and the voidage of a large-void asphalt mixture plate type sample, calculating void volume in the sample, weighing the dry mass of the sample, then performing a seepage test, and taking the minimum water head height of runoff appearing on a runoff surface of the sample as a water head of the sample in a seepage state; then under the water head, seeping water on the plate type sample, after seepage is started for 10min, quickly removing a water storage tank of a seepage meter, collecting permeating water in a period from this moment to a moment when water does not permeate from a permeation surface of the sample, and calculating a dry-wet mass difference value of the plate type sample before and after seepage, thus determining the volume of the water in the voids of the mixture in the seepage state; finally taking a ratio of the volume of the water in the plate type sample to the void volume in the sample as the void saturation of the large-void asphalt mixture in the seepage state. The method is simple, and the water retaining property of the large-void asphalt mixture plate type sample is visually reflected.

Description

technical field [0001] The invention relates to a method for determining the void saturation of a large-void asphalt mixture in a seepage state, and belongs to the technical field of testing and evaluating the internal structure of the asphalt mixture. Background technique [0002] Open Gradation Antiskid Wear Course (OGFC) asphalt mixture is a kind of large void asphalt mixture. The asphalt mixture is used to construct the drainage asphalt pavement of the upper layer, which has excellent drainage, anti-skid, waterproof fog, waterproof splash, anti-glare and noise reduction and other functions. Engineering practice shows that drainage pavement can have the above-mentioned excellent performance, which mainly depends on the large number of interconnected voids in the large-void asphalt mixture. In order to ensure that the large-void asphalt mixture has enough interconnected voids, the current design code in my country requires that its porosity should not be less than 18%, an...

AI Technical Summary

Problems solved by technology

Although some scholars have used this method to successfully calculate the void saturation in the seepage state, the shortcomings of this method are very obvious, as follows: (1) This method relies on CT scanning, which is not used in the field of road engineering; (2) CT scanning is only a few sections of the mixture specimen, and it is too rough to reflect the entire mixture specimen by the water distribution of a few sections; (3) The effect of CT scanning of the mixture mainly depends on Due to the difference in density between voids, mineral materials and water, since the density difference between water and voids is smaller than that between water and mineral materials, this may cause the scanned cross-sectional image to be unable to distinguish voids and water well, thus giving subsequent (4) This method only calculates the void saturation indirectly through the ratio of water to void area, which does not conform to the physical meaning of void saturation.

It can be seen that this method has defects such as lack of equipment, cumbersome process, and rough calculation.

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