630 MPa高强钢筋混凝土大偏压柱受力性能试验

Experimental research on the mechanical properties of concrete column reinforced with 630 MPa high-strength steel under large eccentric loading

设计制作了17根630 MPa新型热处理带肋高强钢筋混凝土大偏心受压足尺柱试件,分析其破坏形态、侧向挠度、钢筋应变、混凝土应变及承载力,以研究630 MPa高强钢筋混凝土大偏心受压柱的受力性能和630 MPa高强钢筋的应力状态及抗压强度发挥水平。结果表明:630 MPa高强钢筋混凝土大偏心受压柱的典型破坏形态与普通钢筋混凝土相同;混凝土受压区所能达到的极限压应变大于现行规范采用的0.0033,有利于偏心受压构件中630 MPa高强钢筋抗压强度的充分发挥,达到与抗拉强度相同的值。各试件承载力试验值均远大于其承载力设计值,两者比值的平均值为1.887,用现行规范对630 MPa级高强钢筋混凝土柱构件进行设计计算是合理且安全的。提出了630 MPa高强钢筋在偏压构件中抗拉和抗压强度设计值取值均为545 MPa的建议,为制定高强钢筋混凝土结构应用技术规程和推广630 MPa高强钢筋的工程应用提供了试验依据。

To study the mechanical properties of high-strength steel reinforced concrete columns under large eccentric loading,and to determine the stress state and the compressive strength level of a new developed 630 MPa ribbed high-strength steel,17 concrete columns reinforced with 630 MPa highstrength steel tested under large eccentric compression were fabricated,and the failure pattern,lateral deflection,strain of steel and concrete,and the bearing capacity were analyzed. The results show that the typical failure pattern of 630 MPa high-strength steel reinforced concrete column with large eccentric compression is the same as that of ordinary reinforced concrete column. The ultimate compressive strain of concrete compression zone is greater than 0.0033 in the current code,which is conducive to give full play to the compressive strength of 630 MPa high strength reinforcement in eccentric compression member,so that the compressive strength reaches the same value as the tensile strength. The test value of bearing capacity of each specimen is much higher than its design value,with an average value of the ratio of 1.887. It is reasonable and safe to design and calculate the 630 MPa high strength reinforced concrete column members by using the current specification. The tensile and compressive strength design values as 545 MPa of the630 MPa high-strength steel in column member subjected to eccentricity is put forward,providing an experimental basis for the compilation of technical specification for high-strength bar in concrete structures and the promotion of 630 MPa high-strength steel in engineering application.