【作者】 刘春生；

【导师】 朱涵；

【作者基本信息】 天津大学 ， 结构工程， 2006， 硕士

【摘要】 橡胶集料混凝土作为一种新型混凝土材料,具有低弹性模量、大变形、高阻尼、能量耗散多及良好的抗裂性等特点,引起混凝土业界的广泛兴趣。本文首次采用国产材料研发出高橡胶掺量的橡胶集料混凝土并对其进行了大量的试验,同时借助数值和解析方法对橡胶集料混凝土的抗压性能进行理论分析,得到了若干新颖的研究成果。并且,在研发基础上,将橡胶集料混凝土用于铺设高速公路收费站,在国内创造了把橡胶集料混凝土应用在公路建设中的实例。在研究方法上,首先从砂浆入手,采用橡胶集料部分的取代砂料,进行了一系列物理力学性能的试验研究,配制出的掺入橡胶集料的砂浆,或称橡胶集料砂浆,其28天抗压强度达38MPa,同时其弹性模量降至3×103MPa以下;本文首次对橡胶集料砂浆的泊松比进行了试验分析,发现其泊松比可超过基准砂浆40%。在此基础上,研发出了一系列橡胶集料混凝土的设计配合比,并对其工程性能进行了全面和系统的分析,结果表明:在实验室条件下,对高橡胶集料掺量(100kg/m3或以上),完全可以配制出C30、C40或更高强度等级,同时综合满足工程设计和施工要求的橡胶集料混凝土,第一次对橡胶集料混凝土应用提供了工程和设计基础。这一点是本文的一个新工作和重点;同时,其弹性模量可以控制在2.30×104MPa以下;本文还对研发出的橡胶集料混凝土梁进行了四点弯曲试验,发现其抗弯极限拉应变可超过400×10-6,以抗弯曲线下的面积所表示的能量显示橡胶集料混凝土的抗弯能量吸收超过基准混凝土4倍;对高橡胶集料掺量下混凝土的阻尼比进行了初步探索,采用了新的试验方法,并对其阻尼比与动态应变衰减进行了比较,二者均表明其阻尼性能有大幅度的增长。在理论方面,本文针对橡胶集料混凝土的抗压性能,根据两维随机骨料的分布理论,首次对橡胶集料混凝土的抗压试件进行了数学模拟,在细观层次上将橡胶集料混凝土离散成为粗集料,橡胶集料,以及水泥砂浆体所组成的三相复合材料,并利用有限元对该模型进行分析。以此种方法建立的模型能够较真实的反映橡胶集料混凝土的受压破坏过程,并首次定量的表明,橡胶集料与砂浆体的界面强度是提高橡胶集料混凝土强度的关键。基于以上研发的工作,决定在青银(青岛～银川)高速公路栾城收费站完全采用橡胶集料混凝土铺筑试验段。面积为2000余平方米,并通过了验收。其橡胶集料掺量为110 kg/m3,共消耗橡胶集料混凝土550余立方米。采用小型机具施工,且养护温度低于10摄氏度,现场施工过程中塌落度在60分钟后大于100mm,28天实际抗压强度超过35MPa,表现出良好的工程适应性,也为形成橡胶集料混凝土的技术规程奠定了基础。更多还原

【Abstract】 Crumb Rubber Concrete (CRC), which is known as a new concrete material, characterized by low Young’s modulus, large deformation, high energy dissipation and extremely good crack resistance. The research on CRC is on the rise in engineering circle. This article presents an experimental analysis on CRC with high crumb rubber volume incorporation, which is firstly mixed using domestically produced materials. And the compressive performance of CRC is analytically and numerically illustrated. Through the researches mentioned above, a series of original research findings are obtained. Moreover, based on the laboratorial conclusions, CRC was firstly used as highway pavement material, which is paved on a 2000m2 highway toll fee area and has been put into practice. This is the first case of application of CRC in roadway construction in China.In this article, the physical and mechanical testes are initially carried on Crumb Rubber Mortar (CMR), which is composed of the ordinary mortar and the crumb rubber that partially substituted the fine aggregate. It’s 28day compressive strength reaches 38MPa with the Young’s modulus of 3×103MPa. For the first time, the CRM Poison Ratio, 40% greater than that of the controlled group, is experimentally analyzed. Then, CRC is compounded and a series of engineering characteristics are studied. What new result shown is that, under the laboratory condition, CRC 28day compressive strength can easily reach 40MPa or even higher and Young’s modulus maintains below 2.30×104MPa ,even the rubber content of CRC reaches more than 100 kg/m3. The four points bending test is conducted and the result expresses that CRC tensile failure strain, two times as much as that of the controlled group, reaches 400×10-6. And the energy absorbing value, calculated as the area under stress-strain curve, is over 4 times greater than that of the controlled group. Meanwhile, the article presents an unprecedented experiment on vibration amplitude and tensile strain attenuation of concrete beams. Result indicates a large increasing of CRC’s damping ratio.In view of compressive property of CRC, the specimen is numerically calculated under compressive load based on the random distribution model of aggregates in a two-dimensional field. CRC was simulated as a structure with three-phases: aggregates, mortar matrix and rubber crumbs. Also, the FEM was employed to calculate the stress and strain fields in the structure. Results obtained in this study更多还原