胶合木-混凝土组合结构在环境与长期荷载共同作用下的蠕变性能研究

Concrete floor systems have bigger stiffness and smaller vibration properties, while wood has high strength to weight ratio and thus the seismic loads and cost of the foundations will decrease. Also timber structure is a kind of green building and its use in structures makes it environmentally friendly and can reduce carbon emissions. For this purpose, through combination of timber and concrete, the generated timber-concrete composite members have the advantage of good structural properties as well as higher fire resistance and good acoustic performance. Also timber can reduce the carbon dioxide emissions compared with steel and concrete and the timber-concrete composite members are quite suitable to the structural industrialization. However, it found in the existing research that the design of this kind of composite members mainly depends on the serviceability limit state. And it is imperative for further research on the creep behavior under environmental and loading conditions...In this view, this project will investigate the creep behaviors of the timber-concrete composite members under environmental and loading conditions, in which to reveal the creep mechanism, study the structural and interfacial creep behaviors, and improve the long-term performance with the introduction of the ductile interfacial connections. Furthermore, it will also decrease the creep through the use of the low-shrinkage concrete and applying of prestress. The project focuses on the following: 1) Experimental and FE analytical behaviors of the interfacial connections of timber-concrete composite members under both short-term loading and long-term loading combined with various environmental conditions. 2) Experimental and FE analytical behaviors of timber-concrete composite members under both short-term loading and long-term loading combined with various environmental conditions. 3) Design method on the load bearing capacity of timber-concrete composite members take consideration of the creep.

混凝土楼屋面具有刚度大，振动小等优点；木材强重比高，其使用可降低地震作用和基础造价，同时木结构绿色环保、可降低碳排放。将木与混凝土结合，形成组合构件，具有结构性能好、适合工业化发展、绿色环保、防火隔声等特色。已有研究表明，此类结构的结构性能主要受正常使用极限状态控制，其在长期荷载与环境温湿度变化条件下的蠕变急需开展深入研究。鉴于此，本项目通过对木-混凝土组合结构在长期荷载与环境温湿度变化共同作用下的蠕变性能研究，揭示其蠕变机理、研究其结构及界面的蠕变性能；引入延性节点以提高其长期性能；同时利用低收缩混凝土和施加预应力等手段进一步降低结构蠕变。重点研究：1）短期荷载作用及长期荷载与环境温湿度变化共同作用下界面节点的结构性能试验研究、有限元分析；2）短期荷载作用及长期荷载与环境温湿度变化共同作用下组合构件的结构性能试验研究、有限元分析；3）考虑蠕变影响的木-混凝土组合构件承载能力设计方法。

混凝土楼屋面具有刚度大，振动小等优点；木材强重比高，其使用可降低地震作用和基础造价，同时木结构绿色环保、可降低碳排放。将木与混凝土结合，形成组合构件，具有结构性能好、适合工业化发展、绿色环保、防火隔声等特色。已有研究表明，此类结构的结构性能主要受正常使用极限状态控制，其在长期荷载与环境温湿度变化条件下的蠕变急需开展深入研究。鉴于此，本项目通过对木-混凝土组合结构在长期荷载与环境温湿度变化共同作用下的蠕变性能研究，揭示其蠕变机理、研究其结构及界面的蠕变性能；引入延性节点以提高其长期性能；同时利用低收缩混凝土和施加预应力等手段进一步降低结构蠕变。重点研究：1）短期荷载作用及长期荷载与环境温湿度变化共同作用下界面节点的结构性能试验研究、有限元分析；2）短期荷载作用及长期荷载与环境温湿度变化共同作用下组合构件的结构性能试验研究、有限元分析；3）考虑蠕变影响的木-混凝土组合构件承载能力设计方法。.项目研究开发了3种预制装配式连接技术，并获得授权发明专利2件、实用新型专利2件；本研究成果已在“Engineering Structures”、“Construction and Building Materials”和“建筑结构学报”等顶级期刊刊出；编制国家全文强制性规范1部、国家标准1部；创新性地提出了预制装配式木-混凝土组合梁的设计计算方法，提出组合梁蠕变变形的预测方法；培养博士研究生2名、培养硕士研究生5名，其中已毕业硕士研究生2名；研究成果作为主要内容之一获江苏省科学技术奖一等奖。.通过项目研究，为木-混凝土组合结构的科研设计、推广应用奠定基础。