黄河超细砂泵送混凝土配合比设计及抗压强度试验研究

发布时间：2018-04-15 08:30

本文选题：黄河超细砂 + 泵送混凝土　；参考：《华北水利水电大学》2017年硕士论文

【摘要】：砂,作为混凝土细骨料的主要成分,主要来源于天然河道,其中细度模数在2.2以上的被称为中砂,3.1以上的被称为粗砂,建筑工程大量使用的是中砂。由于目前我国河砂开采泛滥,中、粗砂产量逐年下降,剩下的都是细砂。其中细度模数小于1.5大于0.7的砂称为特细砂,而对于细度模数小于0.7的砂则称为超细砂(或者称为粉砂),黄河面砂即黄河超细砂是一种类似面粉一样的超细砂。黄河超细砂来自于黄河小浪底库区及其下游地区,其储量丰富、易开采,如果被合理使用对于缓解郑州地区天然砂及人工砂匮乏的严峻形势具有很好的效益。因此,本试验的目的是,用部分黄河超细砂与人工机制砂混合使用,配制出能够满足施工性能和强度要求的黄河超细砂泵送混凝土。本文选取了黄河超细砂及人工砂为主要细骨料,并对其进行了相关的材料性能试验,得出黄河超细砂的部分物理性能指标;通过计算、人工和机器拌合试配、调试,分别得出了C20、C30、C40、C50和C60强度等级混凝土的配合比;然后在人工机制砂内掺入10%、20%、30%、40%和50%的黄河超细砂作为细骨料,制作黄河超细砂混凝土试块,测试黄河超细砂混凝土3d、7d、28d龄期立方体抗压强度值,分析了黄河超细砂掺量对混凝土坍落度、扩展度、保水性、黏聚性的影响,同时也分析了龄期、黄河超细砂掺量对混凝土抗压强度的影响,并对试验数据进行作图分析,得出了不同强度等级泵送混凝土黄河超细砂的适宜掺量。通过试验分析,对比掺有黄河超细砂和未掺有黄河超细砂的混凝土的工作性能和抗压强度,得出C20和C60泵送混凝土中黄河超细砂的最佳掺配比为20%,C30、C40和C50泵送混凝土中黄河超细砂的最佳掺配比为30%。
[Abstract]:Sand, as the main component of concrete fine aggregate, mainly comes from natural river, in which the fineness modulus above 2.2 is called coarse sand above 3.1, and the medium sand is widely used in construction engineering.Due to the flood of river sand mining in our country, the output of coarse sand decreases year by year, and the remaining sand is fine sand.The sand whose fineness modulus is less than 1.5 > 0.7 is called ultrafine sand, while for sand whose fineness modulus is less than 0.7, it is called ultrafine sand (or silt sand). The surface sand of the Yellow River is a kind of super fine sand similar to flour.The ultrafine sand of the Yellow River comes from Xiaolangdi Reservoir area of the Yellow River and its downstream area, which is rich in reserves and easy to be exploited. If reasonably used, it will have a good benefit in alleviating the severe situation of the shortage of natural sand and artificial sand in Zhengzhou area.Therefore, the purpose of this experiment is to prepare the pumping concrete of the super-fine sand of the Yellow River which can meet the requirements of construction performance and strength by mixing some of the ultra-fine sand of the Yellow River with artificial machine-made sand.In this paper, the fine sand and artificial sand of the Yellow River are selected as the main fine aggregate, and some physical performance indexes of the ultra-fine sand of the Yellow River are obtained through the relevant material performance tests.The mix ratio of C20 / C30 / C40C _ (50) and C _ 60 strength grade concrete is obtained respectively, and then the concrete test blocks of the Yellow River ultrafine sand are made by adding 10% (40%) and 50% of the Yellow River ultra-fine sand into the artificial sand.The cube compressive strength value of the ultra-fine sand concrete of the Yellow River at the age of 3 days to 7 days and 28 days was tested, and the influence of the amount of superfine sand added in the Yellow River on the slump, extensibility, water retention and cohesion of the concrete was analyzed, and the age of the concrete was also analyzed.The influence of superfine sand content of Yellow River on compressive strength of concrete is analyzed and the suitable amount of superfine sand for pumping concrete from different strength grades is obtained by drawing and analyzing the test data.Through the test and analysis, the working performance and compressive strength of concrete mixed with and without the superfine sand of the Yellow River are compared.It is concluded that the optimum mixing ratio of the superfine sand of the Yellow River in C20 and C60 pumping concrete is 20% C 30 C 40 and C 50 pumping concrete with the best mix ratio of the Yellow River super fine sand 30.
【学位授予单位】：华北水利水电大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU528

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