The right mixing temperature for creating an asphalt mixture sample is typically specified by the relevant industry standards or project specifications. While Bitumen Test Data Chart (BTDC) values are important for determining the properties of the bitumen binder, the mixing temperature involves considerations for the entire asphalt mixture.

Commonly, the mixing temperature is determined based on the type of asphalt binder used, the gradation of the aggregates, and the specific project requirements. It is often specified in the mix design process, taking into account factors like workability, coating of aggregates, and achieving proper compaction during construction.

Consult the relevant standards or project specifications, such as those from ASTM (American Society for Testing and Materials) or AASHTO (American Association of State Highway and Transportation Officials), for guidance on the recommended mixing temperature for the specific asphalt mixture gradations and binder types you are working with. These standards provide guidelines to ensure the durability and performance of the asphalt mix in the given conditions.

I consider the right mixing temperature is an variable that depending on your purpose and the properties of asphalt. My previous research focused on the temperature of rubber asphalt and aimed to obtained the best paving performance. So I also recommend that you can design the temperature based on lab and site conditions, respectively.

The right mixing temperature depends upon the asphalt binder, more specifically its viscosity. There are local and international standards available to facilitate the selection of temperature but these are also dependent upon the quality of binder recommended for design. As per my experience it is somewhere in the range of 180-200 degree celcius if the asphalt is not mixed on site. The time elapsed enroute to site is another important consideration since there temperature requirements to be maintained during the laying out of the asphalt mix layers.