楼板模板早拆施工技术是一种加快模板周转、降低施工成本的先进施工方法,是当前该领域研究和推广的重点。为了保证楼板模板早拆施工技术的安全度,进行了基于结构设计和施工技术最不利条件的混凝土楼板的模板早拆计算分析,从而界定了第一次拆模时混凝土强度值和拆模时间。简述了楼板模板早拆施工技术原理,归纳了楼板结构设计和施工技术中的各种最不利因素,讨论了模板早拆后楼板存在的破坏形态,针对最不利条件的楼板计算模型进行了数值分析,并进行了混凝土冷凝3d时的强度试验。研究表明,对于支承间距、板厚满足一定条件的楼板,其第一次拆模条件为混凝土强度值≥10MPa,且混凝土冷凝时间≥3d。
The early dismantling formwork construction of concrete floor slab can quicken the formwork turnover,reduce construction cost, and as an advanced technology, has become a key technology for present research and popularization. In order to guarantee security, constructive design/construction technology-based least favorable factors of concrete slab early dismantling formwork was analyzed, then the concrete strength and time of the first time dismantling formwork were defined. Principle of the early dismantling formwork technology of slab was presented. Both several least favorable factors in constructive design and construction technology and destruction pattern of early dismantling formwork slab were also discussed, then the concrete slab model for least favorable condition was analyzed. Strength experiment of concrete after condensation for 3 days was conducted. It is included that the quali-fication for the first time dismantling formwork of a slab with a thickness not less than 100mm and a supporting space not more than 2m is that concrete strength is not less than 10MPa, and concrete condensation time not less than 3 days.