超高性能混凝土（UHPC）高压水射流凿毛处理及修补材料研究

发布时间：2018-04-13 02:09

本文选题：超高性能混凝土 + 修补技术　；参考：《湖南大学》2015年硕士论文

【摘要】：超高性能混凝土(UHPC,Ultra-High Performance Concrete)是近20年发展起来的高强度、高韧性、低孔隙率的一种水泥基材料,因其具备多种优良特性,UHPC被公认为是在未来极具有发展前景和应用价值的一种复合材料。随着UHPC的推广应用,对它的修补技术研究就提上了日程。最常用的混凝土修补方法是首先对要修补的混凝土基体表面进行粗糙处理,然后抹上一层界面剂,以提高界面的粘结强度,最后浇上新的混凝土修补材料并养护。一般新老混凝土粘结界面在收缩差或荷载作用下往往先破坏,是修补后结构的薄弱界面,故粘结界面的性能是修补成败的关键。针对掺有钢纤维的超高性能混凝土高强特性,超高性能混凝土内部随机分布的高强钢纤维对抗折韧性有着大力增强作用,寻找合适方法有效的处理好界面,在修补界面处保留钢纤维并发挥其作用就显得极为重要。本文尝试探索研究超高性能混凝土的修补技术,对掺加了钢纤维的超高性能混凝土处理使用高压水射流来凿毛处理要修补的界面,试探采用聚合物改性超高性能混凝土作为修补材料,探索研究超高性能混凝土修补的可行技术方法,主要研究了以下内容:1、对掺加了钢纤维的超高性能混凝土修补界面,使用高压水射流进行冲击凿毛加工,通过分析凿毛处理界面对良好修补效果的需求,结合基材特性,调整高压水射流设备的各项设置参数(工作压力、刀口高度,刀口孔径,刀头行走速率,切割路线及间距等),得到凿毛处理的合适参数值;2、实验探索研究各种不同聚灰比的聚合物改性超高性能混凝土作为修补材料的可行性,通过测试抗弯拉强度、抗压强度,以及结合施工作业的可操作性能,筛选出较优聚灰比的聚合物改性超高性能混凝土材料。改性用的聚合物分别选用了丁苯乳液、可再分散胶粉、环氧乳液等;3、选用性能较佳的聚合物改性超高性能混凝土对UHPC基体进行修补实验,通过测试对比经修补后分别热养护72小时和标养28d试件的抗弯拉强度,分析确定适合的修补材料和方法,形成可行的超高性能混凝土修补技术工艺流程。
[Abstract]:UHPC-High Performance concrete (UHPC) is a kind of cement-based material with high strength, high toughness and low porosity, which has been developed in recent 20 years.UHPC has been recognized as a kind of composite material with great development prospect and application value in the future because of its many excellent properties.With the popularization and application of UHPC, the research on its repair technology has been put on the agenda.The most commonly used method of concrete repair is to first roughen the surface of the concrete matrix to be repaired, then apply a layer of interface agent to improve the bond strength of the interface, and finally pour in new concrete repair materials and maintain them.Generally, the bond interface of new and old concrete is usually destroyed first under the action of shrinkage difference or load, which is the weak interface of the repaired structure, so the performance of the bond interface is the key to the success or failure of the repair.Aiming at the high strength characteristic of UHPC with steel fiber, the random distribution of high strength steel fiber in UHPC has a great effect on strengthening the flexural toughness, so we can find a suitable method to deal with the interface effectively.It is very important to retain the steel fiber at the repair interface and play its role.This paper attempts to explore and study the repair technology of UHPC. The high pressure water jet is used to repair the interface of UHPC treated with steel fiber.Using polymer modified ultra-high performance concrete (UHPC) as repair material, the feasible technique and method of UHPC mending are explored. The following content: 1 is studied, and the interface of UHPC with steel fiber added into UHPC is studied.The high pressure water jet is used to carry on the impingement hair-chiseling processing, by analyzing the requirement of good repairing effect of the hair-chiseling treatment interface, combining with the characteristic of the substrate, adjusting the setting parameters of the high-pressure water jet equipment (working pressure, cutting edge height, cutting edge aperture, etc.)The suitable parameter value of hair-chiseling treatment was obtained by using the cutting speed, cutting route and spacing. The feasibility of polymer modified ultra-high performance concrete with different ratio of polymer to cement was studied experimentally, and the flexural tensile strength was tested.The compressive strength and the maneuverability of the construction work are combined to select the polymer modified super-high performance concrete material with the optimum aggregate cement ratio.Butadiene emulsion, redispersible rubber powder, epoxy emulsion and so on were used to repair the UHPC matrix.The flexural tensile strength of the specimens after 72 hours of hot curing and 28 days of standard maintenance were tested and compared, and the suitable repair materials and methods were analyzed and determined to form a feasible technological process of super-high performance concrete repair.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU528

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