Structure of the Low-Temperature Asphalt Material Strength Performance Instrument and Meter

Structure of the Low-Temperature Asphalt Material Strength Performance Instrument and Meter

Temperature-Controlled Chamber: The temperature-controlled chamber for low-temperature performance testing of asphalt boasts a wide temperature control range, from -60℃ to +200℃. It can be used not only for testing purposes but even for maintaining the integrity of asphalt material specimens. The chamber is equipped with microprocessor-based control and features programmable constant cooling rates, with a maximum cooling rate of 40℃/hour. The chamber’s internal space is spacious (400mm wide × 280mm deep × 300mm high), allowing it to accommodate at least four sets of ABCD specimens or four sets of ACCD specimens for testing.

Low-Temperature Asphalt Material Strength Performance Instrument Data Acquisition System: The instrument’s built-in data acquisition system can simultaneously connect to 4 temperature sensors and 4 strain gauges, recording the temperature-strain curves for 4 specimens. This data acquisition system includes data cables connected to the sensors.

Low-Temperature Asphalt Material Strength Performance Tester Test Specimen Preparation Kit: The asphalt low-temperature performance tester is standardly equipped with 4 sets of ABCD test molds (including base plates, silicone test molds, steel rings with built-in strain gauges, and temperature sensors).

The low-temperature asphalt material strength performance tester’s steel ring for the ACCD test and the OCD test fixture are not included in the standard configuration and must be purchased separately at an additional cost. The ABCD sample preparation kit also includes a specially developed asphalt filling tool designed by the manufacturer. This tool heats asphalt samples to 220°C and uniformly injects them into the test molds under constant temperature conditions. With the aid of this specialized tool, different operators can achieve greater consistency when preparing specimens, and even the same operator can improve consistency when preparing multiple specimens, thereby enhancing the quality of the test results.

Low-Temperature Asphalt Material Strength Performance Instrument Data Acquisition Software: This specialized data acquisition software can be installed on computers running Windows systems. During testing, users can set acquisition parameters, view temperature and strain data in real time, and generate temperature-strain curves. Test results can be exported to third-party software such as Excel for subsequent processing.

Investigating the relationship between low-temperature performance evaluation indices for asphalt mixtures and pavement cracking conditions is an important basis for rationally establishing standards for evaluating the low-temperature performance of asphalt mixtures. To address the issue that traditional beam-splitting and bending tests exhibit low correlation with actual pavement cracking, field tests were conducted by examining crack spacing across different segments of core samples. Furthermore, a semi-circular bending test (SCB) was introduced to study the low-temperature fracture behavior of asphalt mixtures and to extract relevant data for the BBR test. A relationship was established between pavement crack spacing and key indicators such as fracture energy, fracture toughness, and stiffness modulus of asphalt mixtures. Comparative tests between the SCB and BBR demonstrated that the improved SCB test more accurately reflects the actual low-temperature cracking conditions of asphalt pavements in the Jilin region. Based on these findings, a criterion for assessing low-temperature cracking of asphalt pavements in cold regions was proposed. Through comparative analysis of fracture energy and fracture toughness, it was concluded that using the fracture energy from the SCB test as an evaluation index for the low-temperature performance of asphalt mixtures is more reasonable. These research results have enriched the methods for evaluating the low-temperature performance of asphalt mixtures and provided technical support for improving the design of asphalt pavements to enhance their resistance to low-temperature cracking.