suitably within the range from 10 to 90 and preferably within the range from 20 to 85 to obtain the desired species of polyaluminum compound the ph of the bitumen emulsion should suitably be below 8 preferably below 7 5 more preferably below 7 0 even more preferably below 6 5 still more preferably below 6 0 and most preferably below 5 5 the most preferred ph range for the emulsion is 4 0 5 5 acids may also be added to the composition these acids may be organic or inorganic and monovalent or polyvalent examples of organic acids are carboxylic acids such as formic acid acetic acid oxalic acid malonic acid tartaric acids maleic acid succinic acid and citric acid other organic acids are alkyl esters of phosphoric acid examples of inorganic acids are hydrochloric acid sulfuric acids ortophosphoric acid and phosphorous acid especially preferred acids are hydrochloric acid orthophosphoric acid formic acid acetic acid and propionic acid the alkoxylated amines having formula i could be based on mono or dialkylamines preferably monoalkylamines as starting materials and the hydrocarbyl group s could be straight or branched saturated or unsaturated examples of suitable hydrocarbyl groups are decyl dodecyl myristyl cetyl stearyl oleyl coco alkyl tallow alkyl tall alkyl rapeseed alkyl linseed alkyl as well as hydrogenated unsaturated hydrocarbyl groups such as hydrogenated.