高强珊瑚混凝土配合比工艺与抗压特性研究

发布时间：2018-03-05 21:21

本文选题：珊瑚礁混凝土　切入点：抗压强度　出处：《广西大学》2017年硕士论文　论文类型：学位论文

【摘要】：我国南海珊瑚礁分布广泛,岛礁建设对国家海洋经济的发展起着至关重要的作用。在不破坏岛礁生态环境的前提下,利用岛礁自有的珊瑚碎屑及礁灰岩拌制混凝土,不仅能够有效利用岛礁有限的资源,还能降低陆源建筑材料运输成本,缩短工程建设周期,对于建筑新材料的推广应用和岛礁工程建设开发均具有很重要的科学意义和工程价值。本文在分析国内外珊瑚混凝土室内试验和工程应用研究的基础上,针对国家发改委《关键材料升级换代工程实施方案》中要求50MPa珊瑚混凝土工艺配合比、立方体抗压强度、过渡区结晶矿物种类、钙质砂砂浆与礁灰岩凝结物变形特性等方面进行研究。具体研究成果如下:1、对实验所用钙质砂和礁灰岩碎块的物理性能进行测定,通过单因素实验选定50MPa珊瑚混凝土主控因素及正交设计基准值为:水泥用量700kg/m3,水灰比0.33,砂率50%,粉煤灰掺量10%。2、利用正交实验对珊瑚混凝土立方体试块进行抗压强度测试,经极差和方差分析后得出水泥用量、砂率、水灰比、粉煤灰掺量等影响因素对珊瑚混凝土立方体抗压强度的影响程度逐渐减弱。最终确定50MPa珊瑚混凝上最优配合比为:水泥用量700 kg/m3,水灰比0.33,砂率45%。3、龄期对珊瑚混凝土立方体抗压强度的影响研究表明,珊瑚混凝土属于早强混凝土,其7天抗压强度基本能够达到28天抗压强度的85%以上,但随着水化过程的进行,强度增长趋势逐渐减缓。4、对比不同种类水泥砂浆及水泥砂浆与礁灰岩凝结物的变形特性,发现钙质砂水泥砂浆与礁灰岩凝结物、普通水泥砂浆与礁灰岩凝结物、钙质砂水泥砂浆、普通水泥砂浆、礁灰岩的压缩模量依次增大。5、通过对珊瑚混凝土骨料与水泥浆体界面过渡区位置材料进行X射线衍射实验发现,成分占比相对较高的碳酸镁对珊瑚混凝土骨料与水泥浆体界面过渡区强度的发展具有重要影响。
[Abstract]:Coral reefs in the South China Sea are widely distributed in China, and the construction of reefs plays an important role in the development of the national marine economy. Without destroying the ecological environment of the islands and reefs, the coral debris and limestone of the reefs are used to produce concrete. Not only can the limited resources of the islands and reefs be utilized effectively, but also the transportation costs of land-based construction materials can be reduced, and the construction cycle of projects can be shortened. It is of great scientific significance and engineering value for the popularization and application of new building materials and the construction and development of island and reef projects. This paper analyzes the indoor tests and engineering applications of coral concrete at home and abroad. In view of the requirements of 50MPa coral concrete process mix ratio, cube compressive strength, and the type of crystalline minerals in the transition zone, the National Development and Reform Commission's "key material upgrading Project implementation Scheme" requires 50 MPA coral concrete process mix ratio. The deformation characteristics of calcareous mortar and reef condensate are studied. The concrete research results are as follows: 1. The physical properties of calcareous sand and reef limestone fragments used in the experiment are measured. The main control factors and orthogonal design datum values of 50 MPA coral concrete were selected by single factor experiment: cement dosage 700 kg / m 3, water cement ratio 0.33, sand ratio 50 and fly ash 10. 2. The compressive strength of coral concrete cube test block was tested by orthogonal test. After range and variance analysis, cement content, sand ratio and water-cement ratio are obtained. The influence of fly ash content on cubic compressive strength of coral concrete was gradually weakened, and the optimum mixing ratio of 50 MPA coral was determined as follows: cement dosage 700 kg / m 3, water cement ratio 0.33, sand ratio 45. 3, age to coral coagulation. The study on the influence of the compressive strength of the soil cube shows that, Coral concrete belongs to early strength concrete. The compressive strength in 7 days can reach more than 85% of the compressive strength in 28 days, but as the hydration process goes on, The increasing trend of strength gradually slowed down .4.Compared with the deformation characteristics of different kinds of cement mortar and cement mortar and reef limestone condensate, it was found that calcium sand cement mortar and reef limestone condensate, ordinary cement mortar and reef limestone condensate, The compression modulus of calcareous sand cement mortar, ordinary cement mortar and reef limestone increased by .5. the results of X-ray diffraction experiments on the transition zone between coral concrete aggregate and cement slurry were carried out. Magnesium carbonate, which has a relatively high ratio of composition, has an important influence on the development of the strength of the interfacial transition zone between coral concrete aggregate and cement paste.
【学位授予单位】：广西大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU528

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