钢管超高强混凝土的强度及本构关系预测

Prediction of the Strength and Constitutive Relationship of Very High Strength Concrete Filled Steel Tubular Columns

为安全有效的应用超高强混凝土,通过加载测荷载—应变关系的方法,对钢管超高强混凝土的力学性能进行了研究。研究结果证明,超高强混凝土经钢管约束后,塑性得到很大的改善,改善的幅度随套箍指标Φ的增加而增加,为彻底改善超高强混凝土的塑性,套箍指标Φ应≥0.48。推导出钢管高强超高强混凝土强度的计算公式和预测其本构关系的数学模型,结果证明强度计算值和本构关系预测结果与实测值吻合良好。

The mechanical properties of very highstrength concrete filled steel tubular columns (VHSCFST) were studied.The test results showed that under the confinement of steel tube,the ductility of very highstrength Concrete (VHSC) was improved significantly.The extent of improvement increases as the confinement index Φ increases.In order to thoroughly improve the ductility of VHSC,the value of confinement index Φ should be equal or bigger than 0.48.The formula for the calculation of strength of VHSCFT and the mathematical model for the prediction of constitutive relationship of VHSCFST were obtained based on the test results.They agreed well with measured ones.