When emulsified bitumen gets into contact with aggregates, emulsifiers lose their effectiveness, the emulsion breaks down, and an adhering bitumen film is formed referred to as 'breaking'.
wˌɛn ɪmˈʌlsᵻfˌaɪd bɪtˈuːmɛn ɡˈɛts ˌɪntʊ kˈɑːntækt wɪð ˈæɡɹɪɡˌeɪts, ɪmˈʌlsɪfˌaɪɚz lˈuːz ðɛɹ ɪfˈɛktɪvnəs, ðɪ ɪmˈʌlʃən bɹˈeɪks dˈaʊn, ænd ɐn ædhˈɪɹɪŋ bɪtˈuːmɛn fˈɪlm ɪz fˈɔːɹmd ɹᵻfˈɜːd tʊ æz bɹˈeɪkɪŋ.