瀝青的發泡特性：瀝青在高溫（一般為160℃左右）條件下，加入少量（2%左右)的水，由于水的急速氣化，使瀝青劇烈膨脹，發生“爆炸”產生大量泡沫，同時瀝青表面積迅速增大，體積膨脹數倍數十倍，但在很短的時間內（約1s）瀝青又恢復原狀。

The foaming characteristics of asphalt: when the asphalt is added at a high temperature (generally around 160 degrees Celsius), a small amount (2% or so) of water is added. Due to the rapid gasification of water, the asphalt expands drastically, and a large number of bubbles are generated by the "explosion". At the same time, the asphalt surface area rapidly increases and the volume expands several times to tens of times, but in a very short period of time (about 1s) the asphalt is restored to its original state.

泡沫瀝青發泡性能的評價指標：

Evaluation index of foaming properties of foamed asphalt:

◆膨脹率：泡沫瀝青的大體積／初始瀝青的體積。本工程的膨脹率為20倍。

Expansion rate: the maximum volume of the foamed asphalt / the volume of the initial asphalt. The expansion rate of the project is 20 times.

◆半衰期：泡沫瀝青的大體積縮減1/2大體積時，所用的時間（秒）。本工程的半衰期為20秒。

Half life: the time (seconds) when the maximum volume of foamed asphalt is reduced to the maximum volume of 1/2. The half-life of the project is 20 seconds.

膨脹率越大、半衰期越長的泡沫瀝青拌和效果越好，泡沫瀝青混合料的質量越好。

The greater the expansion rate and the longer the half life, the better the mixing effect of the foamed asphalt, the better the quality of the foamed asphalt mixture.

影響瀝青發泡特性的主要因素：

Main factors affecting asphalt foaming characteristics:

◆瀝青的品種、組分及等級

◆ type, composition and grade of asphalt

◆瀝青發泡時的溫度

◆ temperature during asphalt foaming

◆發泡用水量

◆ foaming water consumption

◆瀝青和水的噴射壓力

◆ spray pressure of asphalt and water

◆加入的表面活性物（發泡劑）

◆ added surfactant (foaming agent)