I. What is the Internal Pressure of Asphalt?
The internal pressure of asphalt mainly originates from its complex internal structure and temperature changes. First, it's important to understand that asphalt is a complex mixture composed of various hydrocarbon compounds and other additives, with various mechanical interactions existing within it. These interactions, including van der Waals forces and hydrogen bonds, exert pressure on the asphalt at the microscopic level.
Second, as a viscoelastic material, the properties of asphalt change with temperature. During temperature changes, due to thermal expansion and contraction, stress is generated within the asphalt, manifesting as internal pressure. This change in internal pressure due to temperature variations is particularly significant in areas with large diurnal or seasonal temperature differences.

II. What is the Compressive Strength of Asphalt and How Much Does It Measure?
The compressive strength of asphalt generally refers to its ability to resist compression or indentation under pressure. This performance indicator is crucial for understanding the durability, load-bearing capacity, and rationality of asphalt pavement design.
Compressive strength is typically measured using standardized testing methods, such as applying pressure to an asphalt sample under specified conditions and measuring its resistance to compression. The specific compressive strength value varies depending on factors such as the type of asphalt, its composition, production process, and testing conditions.
Generally, the compressive strength of ordinary asphalt mixtures ranges from approximately 2.0 to 5.0 MPa. Higher quality asphalt or specially formulated asphalt mixtures may have higher compressive strengths. However, these values ??are only for general reference; the actual compressive strength should be determined through professional testing.
It is important to note that higher compressive strength in asphalt mixtures is not always better. It needs to be considered in conjunction with other performance indicators such as fatigue resistance, abrasion resistance, and skid resistance to achieve optimal pavement performance and service life.
In summary, the internal pressure and compressive strength of asphalt are important indicators for evaluating asphalt performance. Understanding these concepts and values ??helps us better select and use asphalt materials to construct higher-quality and more durable pavements.