An acid modified asphalt binder is combined with an emulsifier solution to produce an emulsified asphalt binder. The acid modified asphalt binder may be formed by combining an asphalt binder, a phosphorous-based acid, and, optionally, a polymer modifier. The emulsifier solution may be produced by forming an aqueous solution of an amine and a phosphorous-based acid, which forms an aqueous solution comprising an amine phosphate. The emulsified asphalt binder may be combined with an aggregate to form a paving material. In other examples, the emulsified asphalt binder may be used alone, for example in a chip seal application, or in a diluted form, for example in a fog seal application.