现浇板砼收缩与温差联合作用裂缝控制计算

Calculation of Crack Control in Cast-in-Situ Concrete Slab under Combined Action of Concrete Contraction and Temperature Difference

分析现浇板因砼收缩和温差影响的组合作用裂缝的产生机理。通过微元体建立建筑外周梁与室内板间的静力平衡关系,导出以砼极限收缩应变值ε反映砼材料质量影响的外梁温差内力计算公式。提出现浇板抗第二类荷载裂缝的计算模式和相应的强度计算式。

This paper analyzes mechanism of crack development in cast - in - place concrete under combined action of concrete contraction and temperature difference. A calculation formula for internal force of temperature difference in peripheral beam is deduced according to unit static equilibrium between the peripheral beam and interior slab, a calculation model and corresponding strength formula are proposod for the cracks induced by the second kind loads in cast - in situ concrete.