Method for measuring density of mixture of compacted asphaltum

Abstract

First, mass of dried test piece in air is weighed. Then, sealed test piece is prepared by using liquid silicone rubber as sealing medium to seal dried test piece. Weighing masses of sealed test piece in air and in water obtains density of test piece. Steps of sealing procedure are as: mixing round bicomponent of liquid silicone rubber evenly; coating liquid silicone rubber on surface of dried test piece evenly to seal surface of the test piece; after liquid silicone rubber being solidified at normal temperature, sealed test piece by silicone rubber is obtained. Features of the invention are: good sealability, and accurate testing result.

Description

technical field [0001] The invention relates to a method for measuring parameters of asphalt and asphalt mixture, in particular to a method for measuring the density of compacted asphalt mixture. Background technique [0002] The density measurement test of compacted asphalt mixture is a very common and important test in the detection of high-grade asphalt pavement and asphalt mixture test, and its accuracy directly affects other important indicators of compacted asphalt mixture such as void ratio, mineral aggregate Accuracy of calculations such as gaps. At present, the "wax seal method" is commonly used at home and abroad to measure the relative gross volume density of asphalt concrete or asphalt macadam mixture specimens with a water absorption rate greater than 2%; In the "Compacted Asphalt Mixture Density Test (Wax Seal Method)", the number is T0707-2000 in the "Compacted Asphalt Mixture Density Test (Wax Seal Method)", the "wax seal method" ...

AI Technical Summary

Problems solved by technology

The shortcomings and shortcomings of using the "wax seal method" to measure the density of compacted asphalt mixture mainly include: (1) The test procedures are relatively cumbersome, and the requirements for test operators and equipment are relatively high, especially for temperature control equipment. If it is required to have a refrigerator with precise temperature control (the specification requires 4°C-5°C), an electric furnace or a gas furnace with good temperature control performance to accurately control the melting temperature of paraffin, because when performing the "wax sealing method" test, whether the test temperature control is accurate It has a great impact on the accuracy of the test results. The temperature control is not accurate, and the proportion of paraffin entering the voids in the compacted asphalt mixture specimens will also be inconsistent, which will definitely affect the comparability of the test results. Advanced temperature control equipment needs to spend a lot of money, and it is difficult to carry out the "wax seal method" test in a laboratory equipped with ordinary equipment; (2) During the test process, at the junction of each surface of the wax seal The paraffin wax at the junction of the two planes) may crack after cooling or accidentally knocked during the process of moving the wax-sealed specimen, causing the paraffin to fall off from the surface of the specimen, resulting in the inability of the paraffin to completely seal the specimen, which will affect The accuracy of the test results; (3) The sealing process of the test piece requires a special fixture, but no matter what kind of fixture is used, the process of taking the test piece out of the paraffin liquid and disengaging it from the test piece will affect the paraffin sealing of the test piece. The appearance of the test piece will even stick away the paraffin wax on the surface of the test piece (this often happens when talcum powder is applied), thus affecting the sealing performance of the wax-sealed test piece; (4) For test pieces with large gaps, even if After the specimen is frozen, the high-temperature paraffin liquid will not immediately solidify on the surface of the specimen, and part of the paraffin liquid will still enter the internal pores of the specimen. At the same time, there are still some large pores that cannot be sealed, which will also affect the test results. Accuracy; (5) If other tests need to be done on the test piece after the density is measured, in order to facilitate the removal of paraffin, it is also necessary to apply a thin layer of talcum powder on the surface of the dry test piece in advance, and then weigh the talcum powder and the dry test piece The total mass m s But this is difficult to operate in the actual process, because there is no adhesion between the dry talcum powder and the dry test piece, and the talcum powder is easily dropped or stuck to other contact objects during the moving of the test piece , which will lead to large errors in the whole test results. In addition, the relative density of talcum powder to water must be measured first to calculate the density of the test piece after smearing talcum powder, which makes the whole test process more complicated and Increased factors of experimental error

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