钢纤维特种混凝土制备及应用技术研究

发布时间：2018-01-25 07:49

本文关键词： 钢纤维道路材料工作性能力学性能拌合工艺　出处：《哈尔滨工业大学》2014年硕士论文　论文类型：学位论文

【摘要】：水泥混凝土在道路工程中已得到了广泛的应用,但是,其存在抗拉强度低,韧性较差等缺陷。而钢纤维具有增强、增韧等作用,将混凝土与钢纤维进行复合可以提高混凝土材料的韧性和抗拉强度,提高道路的使用寿命和可靠性。本课题针对实际工程要求,在普通混凝土基础上研究掺加一定量的钢纤维,从而制备出能满足要求的钢纤维混凝土。本课题首先根据目标要求,研究不同水灰比、单位体积用水量、砂率及掺合料(粉煤灰、矿粉)用量对混凝土性能的影响,配制出普通混凝土。在此基础上根据现有两种不同水泥、外加剂、钢纤维,研究不同原材料种类对混凝土工作性能和力学性能的影响,研究并制备了C40和C55两种钢纤维混凝土,在制备过程中也研究了钢纤维混凝土的成型和拌合工艺。主要研究结果:在相同原材料条件下,钢纤维C40混凝土配合比为:W/C为0.36,钢纤维97.5 kg/m~3,砂率45%;钢纤维C55混凝土配合比为:W/C为0.32,钢纤维117 kg/m~3,砂率50%。两种混凝土单位用水量为180 kg/m~3,粉煤灰掺量为10%,矿粉掺量为20%,外加剂掺量都为1%。投料工艺为:先投砂、石子、钢纤维,搅拌1.5min;再投胶凝材料搅拌约1min;最后投水和外加剂,搅拌约3min;出机后的混凝土分散性较好。试验中发现随着钢纤维掺量的增加,混凝土的工作性能不断降低,过量掺加会导致工作性能急剧降低,极易发生团聚。C40和C55在不影响施工性能前提下钢纤维最大掺量分别为97.5kg/m~3和117kg/m~3。在此掺量下,相对于空白样,C40和C55混凝土28d抗压强度分别提高了20%和27%,而7d和28d的劈裂强度分别提高了约80%和100%。在道路材料混凝土中掺加钢纤维,可以有效改善混凝土的性能,提高混凝土的抗裂阻韧等特性,提高路面的使用寿命。本课题针对路面混凝土材料的缺陷,通过在路面工程材料中掺加钢纤维制备钢纤维混凝土,不但满足实际工程要求,同时也对钢纤维在我国路面材料的大范围应用提供重要的理论和应用指导。
[Abstract]:Cement concrete has been widely used in road engineering, but it has some defects such as low tensile strength and poor toughness, while steel fiber has the function of strengthening and toughening. The composite of concrete and steel fiber can improve the toughness and tensile strength of concrete material and improve the service life and reliability of road. On the basis of ordinary concrete, a certain amount of steel fiber is added to prepare the steel fiber concrete that can meet the requirements. Firstly, according to the objective requirements, the different water / cement ratio and water consumption per unit volume are studied. The influence of sand ratio and the amount of admixture (fly ash, mineral powder) on the performance of concrete is prepared. Based on this, two kinds of cement, admixture and steel fiber are used. The effects of different kinds of raw materials on the working and mechanical properties of concrete were studied and two kinds of steel fiber reinforced concrete (C40 and C55) were prepared. The main results are as follows: under the same raw material condition, the mix ratio of steel fiber C40 concrete is 0. 36% W / C. Steel fiber 97.5 kg / m ~ (3), sand rate 45%; The mix ratio of steel fiber C55 concrete is 0. 32, steel fiber is 117 kg / m ~ (3), sand ratio is 50. The unit water consumption of two kinds of concrete is 180 kg/m~3. The content of fly ash is 10, the amount of mineral powder is 20 and the amount of admixture is 1. The feeding process is: first throwing sand, stone, steel fiber, stirring 1.5 min; The gelation material was stirred for about 1 minute. Finally, water and admixture are added and stirred for about 3 mins; It is found in the experiment that with the increase of steel fiber content, the working performance of concrete decreases continuously, and the excessive addition of concrete leads to a sharp decrease in the working performance. It is easy to reunite. C40 and C55 are 97. 5 kg / m ~ (3) and 117 kg / m ~ (3) respectively without affecting the construction performance. Under this addition, compared with the blank sample, the maximum content of steel fiber is 97. 5 kg / m ~ (3) and 117 kg / m ~ (3) respectively. The compressive strength of C40 and C55 concrete increased by 20% and 27% respectively. And the splitting strength of 7d and 28d increased about 80% and 1000.The addition of steel fiber into road material concrete can effectively improve the performance of concrete, improve the crack resistance and toughness of concrete and so on. In view of the defects of pavement concrete materials, steel fiber reinforced concrete is prepared by adding steel fiber to pavement engineering materials, which not only meets the practical engineering requirements. At the same time, it also provides important theoretical and practical guidance for the wide application of steel fiber in pavement materials in China.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U414

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