文档介绍：
冻融循环对钢筋混凝土简支梁的影响#
吴海亮,慕儒**
(河北工业大学土木工程学院,天津 300401)
5
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摘要:研究了冻融循环对钢筋混凝土简支梁承载力、挠度的影响。理论计算和有限元分析表
明,冻融循环作用下,简支梁的承载力下降、跨中挠度增加。当简支梁顶面受冻受压区混凝
土劣化时,梁的挠度增加较多;当简支梁底面受冻受拉区混凝土劣化时,梁的挠度变化较小。
关键词:冻融循环;耐久性;挠度;承载力
中图分类号:TU528. 01
Influence of freeze-thaw cycles on reinforced concrete beams
WU Hailiang, Mu Ru
(School of Civil Engineering, Hebei University of Technology, Tianjin 300401, China)
15
Abstract:
The effect of freeze-thaw cycles on the properties of a simple supported reinforced
concrete beam was investigated. The results of theoretical analysis and finite element method
show that after freeze-thaw cycles the bearing capacity of the beam decreases, whilst the
deflection of the beam increase. When the top surface of the beam subjected to freeze-thaw cycles,
which means the degradation of concrete mainly occurs pression region of the beam, the
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deflection of the beam decreases significantly. However, when the bottom surface of the beam
subjected to freeze-thaw cycles, saying the degradation mainly takes place in tension region of the
beam, the influence on the deflection of the beam is little.
Key words: freeze-thaw cycles, durability,deflection, bearing capacity
0 引言
混凝土的抗冻性问题受到普遍重视[1],自 Powers 于 1945 年提出了混凝上冻融破坏的静
水压假说[2]之后,有学者陆续提出了混凝土冻融循环破坏的渗透压理论[3]、极限饱水值理论
[4]
为冻融循环作用下,混凝土中形成微裂缝,使得混凝土材料变得疏松、孔隙粗化、孔隙率增
大,宏观表现为相对动弹性模量下降、表面剥落等现象。