摘要
泡沫混凝土在应用中存在强度偏低、开裂、吸水等缺陷,在长期荷载作用下,泡沫混凝土会产生开裂,需要研究泡沫混凝土的刚度软化与剪力传递关系模型,准确描述混凝土结构长期变形及受力行为的徐变耦合特性,掌握服役期内的结构的长期变形及受力状态,为建筑结构防护提供参考。传统模型中仅考虑未开裂部分混凝土的徐变及开裂混凝土对整体刚度的影响,在裂缝的存在,使得混凝土结构刚度降低。提出一种基于裂缝坐标系下泡沫混凝土刚度软化与剪力传递关系模型,分析泡沫混凝土徐变产生及载重分配的机理,得到单轴受压条件下本构关系,按等效应力-应变关系来计算变化的切线弹性模量,在裂缝坐标系下,较准确地描述了泡沫混凝土的平均盈利比率变化与温度和刚度软化之间的关系,经算例验证表明,计算结果可靠,计算精度满足工程使用要求。
The foam concrete has low intensity, cracking, water and other defects in application, under long-term load, foam concrete cracking, it needs to study the foam concrete stiffness softening and shear transfer model, describe the creep coupling characteristics of long-term structural deformation and stress behavior, grasp the long-term deformation. In the period of structure and stress state, it provides reference for building structure protection. In the traditional models only consider the creep and cracking of concrete cracking of concrete is not part of the impact on the overall stiffness, in the presence of cracks, the concrete structure stiffness reduction. A foam concrete crack coordinates is proposed based on the stiffness softening and shear transfer model, the mechanism of bubble of concrete creep and load distribution is analyzed, the condition of uniaxial compression constitutive relationship is obtained, tangent modulus of elasticity according to equivalent stress-strain relation to calculate the change in crack, it can accurately describe the foam concrete average profit ratio change with temperature and the relationship between the stiffness softening, through example validation shows that, the calculation results are reliable, the calculation accuracy can meet the engineering requirements.
出处
《科技通报》
北大核心
2015年第2期230-232,共3页
Bulletin of Science and Technology
基金
内蒙古自治区教育厅"稀土添加剂对轻型墙体节能材料泡沫混凝土的性能研究"(NJZC13344)
关键词
裂缝坐标系
泡沫混凝土
刚度软化
crack coordinates
foam concrete
shear stiffness softening
