防范砖混结构住宅顶层砌体温变裂缝的措施

Measures Preventing Temperature Change Cracks of Top Brickwork of Residences of Brick and Concrete Structure

砖混结构住宅顶层砌体受温度变化产生裂缝现象,是砌体和混凝土构件的不同线膨胀率而产生的质量事故。文章通过在规范规定防止砌体裂缝技术指导下,对顶层纵向圈梁上增置伸缩缝措施:在最冷时段对圈梁钢筋施加预应力,同时在最冷或最热时段时,对圈梁分段设置后浇段并增设外墙圈梁保温。再合理划分顶层预制板上刚性层的分隔缝和现浇板分割缝等措施,能有效防止和减轻砌体裂缝的产生。

Crack of top brickwork of residences of brick and concrete structure because of temperature change is a quality accident caused by different linear expansion of brickwork and concrete member.Under the guidance of the technology preventing brickwork cracks in the regulations,this article proposes addition of dilatation joint to top longitudinal ring beam：prestressing the steel bar of the ring beam in the coldest period,in addition,setting up post-pouring section for the ring beam by sections and adding thermal insulation of ring beam of exterior wall in the coldest or hottest period,and then the measures such as rational division of diving joint of rigid layer on the top precast slab and diving joint of cast-in-situ concrete slab are adopted,which can effectively prevent and reduce brickwork cracks.