In recent years, the laboratory of the pavement branch has strengthened the investigation and connection between the rear mixing and front paving and rolling of asphalt mixtures, and strengthened the exploration of the relationship between the properties of raw materials and the mixing characteristics of asphalt mixtures. With the continuous and steady increase in asphalt mixture mixing production, the workload of the laboratory continues to increase. In order to timely grasp the quality situation and meet the needs of production development and engineering construction, laboratory staff actively explore and work hard on the basis of following experimental principles and procedures.
Based on specific work situations, for example, there is an important indicator of fine aggregate called sand equivalent, which has a significant impact on the quality of asphalt pavement. According to the test procedure, the sand equivalent test takes at least 6 hours from the sampling of raw materials to the production of test results. During the construction process, the raw material consumption for mixing asphalt mixture is high, and the storage capacity is also limited. In this situation, it is urgent to quickly determine whether the transported fine aggregate is qualified. Once judged qualified, using qualified aggregates for mixing the mixture can ensure normal production progress. In the actual testing process, it is often unnecessary to know the specific test results, only to know whether the detection indicators of the raw materials are within the qualified range. Under this concept, by accumulating a large amount of experimental data to control quality errors, it is possible to determine whether the sand equivalent is qualified in a relatively short period of time. For example, for the grading of aggregates and asphalt mixtures, whether using dry screening method or water washing method, the specific process takes more than 6 hours. By measuring the grading error between the dry sieving method and the water washing method within a certain period of time, an error correction data table can be obtained, which can provide sufficiently accurate data for adjusting the mixing grading of the mixture in a relatively short period of time. In terms of asphalt indicators, mixture porosity, and other aspects, the laboratory has conducted a large amount of experimental data analysis and continuously improved working methods to better serve the quality management of asphalt mixtures. |
