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(1 四川大學水利水電學院，成都 610065； 2 西北核技術研究所，西安 710024；3 中國人民解放軍77573部隊，拉薩 850000)

［摘要］運用MTS815 Flex Test GT巖石力學試驗系統(tǒng)對C30和C50混凝土圓柱體試件進行單軸、三軸壓縮試驗，得到了混凝土的應力應變全過程曲線，研究了不同圍壓下混凝土的強度和變形特性。結果表明：Newman非線性方程較Richart線性方程更為準確地表達了強度與圍壓的變化規(guī)律，隨著圍壓的增加，兩種強度等級混凝土對應圍壓的強度差別逐漸減小；混凝土的抗壓強度和破壞形態(tài)存在一臨界圍壓σ3c，高于此臨界圍壓時破壞階段為應變軟化，且抗壓強度受混凝土強度等級影響較小，反之為應變硬化；隨圍壓的增大，混凝土材料由脆性逐漸過渡為延性，變形能力增大，彈性模量、割線模量減小，泊松比增大，峰值軸向應變增大，其變化關系可用Ansari線性方程表示。

［關鍵詞］混凝土；高圍壓；強度；變形

中圖分類號：TU528-1文獻標識碼：A文章編號：1002-848X(2011)05-0085-04

Experimental study on concrete strength and deformation characteristics under high confining pressure

Li Qingsong¹, Xu Jin¹, Xiong Yibo², Liu Yazhou¹, Wu Ping¹, Li Ganglin¹, Zhao Lin³(1 College of Water Resource & Hydropower, Sichuan University, Chengdu 610065,China；2 Northwest Institute of Nuclear Technology, Xi’an 710024, China；3 77573 Army of CPLA, Lhasa 850000, China)

Abstract:The uniaxial compression tests and triaxial compression tests were performed on the concrete cylinder specimens of C30 and C50 using MTS815 Flex Test GT rock mechanics test system. During the whole loading process, the stress-strain curves of the concrete specimens were obtained and the strength and deformation characteristics were investigated under different confining pressures. The experimental results show that Newman nonlinear equation can describe the evolution rule of strength with the changing of confining pressure more accurately than Richart linear equation, and with the increase of the confining pressure the difference of strength corresponding to the same confining pressure between these two strength grades concrete becomes gradually smaller. According to the compressive strength and failure mode of concrete specimens, there is one critical confining pressure σ3c, when the confining pressure applied above the critical confining pressure the specimens will behave strain softening and the compressive strength is hardly affected by the concrete grade, when the confining pressure applied below the critical confining pressure the specimens will behave strain hardening. With the increasing of the confining pressure, the concrete materials behaves as brittle and transfers to ductile gradually, and the deformation capacity will enhance, elastic modulus and secant modulus reduce, Possion’s ratio increases, the axial strain corresponding to peak value of stress also increases, as well as the stress-strain relation describes well by the Ansari linear equation.

Keywords:concrete; high confining pressure; strength; deformation

作者簡介：李青松，碩士研究生，Email：sophia_2081@163.com。

參考文獻

［1］宋玉普.多種混凝土材料的本構關系和破壞準則［M］.北京：中國水利水電出版社，2002.

［2］閆東明，林皋.三向應力狀態(tài)下混凝土強度和變形特性研究［J］.中國工程科學，2007，9(6)：64-70.

［3］過鎮(zhèn)海，王傳志.多軸應力下混凝土的強度和破壞準則研究［J］.土木工程學報，1991，24(3)：1-14.

［4］過鎮(zhèn)海.混凝土的強度與變形—試驗基礎和本構關系［M］.北京：清華大學出版社，1996.

［5］陳惠發(fā)，薩里普 A F.混凝土和土的本構方程［M］.北京：中國建筑工業(yè)出版社，2004.

［6］謝和平，董毓利，李世平.不同圍壓下混凝土受壓彈塑性損傷本構模型的研究［J］.煤炭學報，1996，21(3)：265-270.

［7］RICHART F E，BRANDTZAEG A，BROWN R L.A study of the failure of concrete under combined compressive stresses ［R］.Bulletin No.185，Engineering Experiment Station，Unviersity of Illinois，Urbana，1928.

［8］NEWMAN J B.Concrete under complex stresses ［R］.Development in concrete technology 1，Lydon F D(ed)，Applied Science，London：1979.

［9］ANSARI F，LI Q.High-strength concrete subjected to triaxial compression ［J］.ACI Materials Journal，1998，95(6)：747-755.