A second mechanism is the matrix swelling when the encapsulated hygroscopic salts exposed to water or moisture start to rehydrate and to dissolve.
ɐ sˈɛkənd mˈɛkənˌɪzəm ɪz ðə mˈeɪtɹɪks swˈɛlɪŋ wɛn ðɪ ɛŋkˈæpsjʊlˌeɪɾᵻd hˌaɪɡɹəskˈɑːpɪk sˈɔlts ɛkspˈoʊzd tə wˈɔːɾɚ ɔːɹ mˈɔɪstʃɚ stˈɑːɹt tə ɹᵻhˈaɪdɹeɪt ænd tə dɪsˈɑːlv.