一外廊式砖混结构房屋,其外廊作法为现浇钢筋混凝土挑梁上放置预制板,用细石混凝土灌缝,再在预制板上现浇40mm厚C10混凝土层,最后做25mm厚水泥砂浆面层。我单位在某工程外廊做好后一个星期时,在挑梁上方的板端便出现了一条平行挑梁的纤细裂缝,随后不断发展,到 A porch-type brick-concrete structure house whose exterior porch is constructed by placing prefabricated panels on cast-in-site reinforced concrete cantilever beams, and is filled with fine stone concrete, then cast on a prefabricated panel with a 40mm thick C10 concrete layer, and finally made of 25mm thick cement. Mortar surface. One week after the completion of a project’s verandah, a flat crack in a parallel beam was found on the end of the beam above the beam, and then continued to develop.