【作者】 李达；

【导师】 彭自强；

【作者基本信息】 武汉理工大学 ， 土木工程， 2018， 硕士

【摘要】 在远海地区的工程建设逐渐增多,珊瑚礁砂混凝土便于就地取材,加快建设速度,提高保障能力,降低修建与维护成本。但主要材料组成的改变,必然影响到材料的力学性能,特别是在海洋区域复杂使用环境,对其力学性能提出了更高的要求。严峻的服役环境,需要设计者对混凝土的力学性能有更为深入的掌握,对材料的损伤行为及发展有清晰的认识,同时,复杂的力学分析需要更为有效的多轴材料模型。目前常规混凝土已经进行了较为充分的基于声发射的损伤行为试验研究,也开展了不少多轴力学性能试验与理论研究,但对于珊瑚礁砂这种新的建筑材料,尚缺少有效的研究成果。本文从力学加载试验与声发射试验两个角度描述了珊瑚礁砂混凝土在单轴以及双轴受压状态下的力学性能,试验主要成果如下:(1)获得了单双轴受压状态下珊瑚礁砂混凝土受压过程的全曲线,对于各阶段的变化特征予以分别描述,构建了受载全过程的应力应变本构方程。(2)获得了不同应力比下珊瑚礁砂混凝土的声发射特征参数,研究加载过程中的裂缝开展,并建立声发射活性函数,为后续损伤演化研究提供依据。(3)通过不同水胶比混凝土对比试验,获得了混凝土强度随着水胶比改变的变化规律;通过同种配合比混凝土在不同应力比下的对比试验,获得了应力比对双轴抗压强度的影响。(4)获得了描述每种配合比混凝土损伤演化方程,包括Weibull方程与Ramberg-Osgood方程等。(5)获得了双轴加载下珊瑚礁砂混凝土的破坏准则。(6)通过声发射试验得到了该种混凝土在双轴受压状态下的损伤演化方程。更多还原

【Abstract】 The number of construction projects in the far sea area has gradually increased,and coral reef sand concrete is easy to get as local materials,speeding up the construction speed,increasing indemnity capabilities,and reducing construction and maintenance costs.However,the change of the main material composition will inevitably affect the mechanical properties of the material,especially in the complex environment in the marine area,and it need higher requirements for its mechanical properties.The severe environment requires the designer to have a deeper understanding of the mechanical properties of the concrete,and has a clear understanding of the damage behavior and development of the material.At the same time,complex mechanical analysis requires a more effective multi-axial material model.At present,the ordinary concrete has been subjected to a relatively experimental study on the damage behavior based on acoustic emission,and a number of multi-axial mechanical properties tests and theoretical studies have also been conducted.However,there is no effective research for coral reef sand,a new building material.In this paper,the mechanical properties of coral reef sand concrete under uniaxial and biaxial compression are described from two aspects of mechanical loading test and acoustic emission test.The main results of the test were as follows:(1)The full curves of the coral reef sand concrete subjected to uniaxial and biaxial compression are obtained.The characteristics of the changes in each stage are described separately,and the stress-strain constitutive equations of the entire load process are constructed.(2)Acoustic emission characteristic parameters of coral reef sand concrete under different stress ratios were obtained.The development of cracks in the loading process was studied and the acoustic emission activity function was established to provide basis for subsequent damage evolution research.(3)Through the comparative test of concrete with different water cement ratio,the change law of increasing concrete strength with water cement ratio was obtained;through the comparative test of concrete with different mix ratio under different stress ratios,the stress ratio biaxial resistance was obtained.(4)The damage evolution equation describing each concrete ratio is obtained,including Weibull equation and Ramberg-Osgood equation.(5)The failure criteria of coral reef sand concrete under biaxial loading was obtained.(6)The damage evolution equation of the concrete under biaxial compression was obtained by acoustic emission test.更多还原