Method of making sulfur extended asphalt modified with crumb rubber

A method of making a sulfur rubber asphalt binder composition comprising the steps of:

• mixing a crumb rubber material with a base asphalt at a first predetermined temperature in a shear blender for first predetermined amount of time to create an asphalt crumb rubber mixture;
• placing the asphalt crumb rubber mixture in a sealed container in an oven at the first predetermined temperature for a second predetermined amount of time to create an aged asphalt crumb rubber mixture;
• and
• adding elemental sulfur to the aged asphalt crumb rubber mixture and mixing for a third predetermined amount of time at a second predetermined temperature such that intimate mixing of the elemental sulfur and the asphalt crumb mixture is achieved;
• where
• the asphalt is about 54 weight percent, the elemental sulfur is about 40 weight percent and the crumb rubber material is about 6 weight percent, each by weight of the sulfur rubber asphalt binder composition.

A method of making a sulfur rubber asphalt binder composition comprising the steps of:

• mixing a crumb rubber material with a base asphalt at a first temperature in a shear blender for first amount of time to create an asphalt crumb rubber mixture;
• maintaining the asphalt crumb rubber mixture in a sealed container in an oven at the first temperature for a second amount of time to create an aged asphalt crumb rubber mixture wherein the asphalt crumb rubber mixture is cured and reacted in the sealed container free of external mixing for the second amount of time;
• and
• introducing elemental sulfur to the aged asphalt crumb rubber mixture and mixing for a third amount of time at a second temperature such that the sulfur rubber asphalt binder composition forms;
• where the elemental sulfur is in a range of from about 30 to about 50 weight percent and the crumb rubber material is in a range of from about 1 to about 6 weight percent, each by weight of the sulfur rubber asphalt binder composition.