摘要
利用大型静动真三轴试验机,进行高强高性能混凝土和普通混凝土在不同应力比下的单轴、双轴、三轴压强度与变形试验研究。多轴压试块尺寸为100mm×100mm×100mm,减摩措施为3层黄油中间加3层塑料薄膜的减摩垫层,加载方式为单调比例加载。阐述试件的破坏形态和机制;测得多轴强度、峰值应变和应力-应变曲线,分析应力比对其影响规律;剖析2种混凝土多轴力学性能的差异。试验结果表明:多轴压下2种混凝土极限强度σ3f和峰值应变ε3p在所有应力比下都分别大于其单轴压强度fc和峰值应变εcp,尤其是在三轴压下更为明显;而且σ3f和ε3p相对于fc和εcp的提高倍数取决于混凝土的脆硬性、应力状态和应力比。建立在双轴压和多轴应力状态下的高强高性能混凝土和普通混凝土Kupfer-Gerstle和Ottosen破坏准则公式,为2种混凝土结构(如桥梁与隧道工程、地下工程、建筑工程等)在多轴压下的强度分析提供试验和理论依据。
The strength and deformation experiments of plain and high-strength high-performance concrete （HSHPC） and normal strength concrete（NSC） with various stress ratios under uniaxial, biaxial and triaxial compressions are completed, using the large static-dynamic true-triaxial machine. The multiaxial compression tests are performed on 100 min×100 mm×100 mm concrete specimens with friction-reducing pads（three layers of butter and three layers of plastic membrane） placed between platens and specimens under monotone proportional loading. Failure modes and failure mechanism of specimens are described. The multiaxial strengths, strains under peak stress and stress-strain curves are measured; and the influence law of the stress ratios and the difference of multiaxial mechanical property between HSHPC and NSC are also analyzed. The experimental results show that ultimate strength σ3f and principal strain e3p of HSHPC and NSC under multiaxial compression are greater than uniaxial compressive strength fc and strain ε3p under all stress ratios respectively, especially under triaxial compression. Moreover, the increasing multiple ratios of σ3f and ε3p relatively to fc and ε3p depend on brittleness-stiffness of concrete, stress state and stress ratios. The formula of Kupfer-Gerstle and Ottosen＇s failurecriterion for plain HSHPC and NSC under biaxial compression and multiaxial stress states is proposed, which provide experimental and theoretical foundation for strength analysis of HSHPC and NSC structures such as bridge and tunnel engineering, underground engineering, and building engineering, etc
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2008年第A02期3575-3584,共10页
Chinese Journal of Rock Mechanics and Engineering
关键词
建筑材料
高强高性能混凝土
普通混凝土
应力比
多轴压强度
峰值应变
应力-应变关系
building materials
high-strength high-performance concrete（HSHPC）
normal strength concrete（NSC）
stress ratios
multiaxial compression strength
peak strain
stress-strain relationship
