Study On Character And Construction Technology Of Hydraulic Pump Concrete

The riverhead defending project of leading Luan River to Tianjin in Tianjin city is not only the key project item of Tianjin city but also a very famous large-scale across-valley long water diversion project. In the light of the reality of the project, looking for an optimum construction technique, which can meet the demand of time limit, quality, security and environmental protection and reduce the investment of project, is worthy of being researched and is a very realistic significance topic. Under this situation, the author did some researches on construction technique of hydraulic concrete, mix proportion design of pump concrete and alkali aggregate reaction. The main work and results shows as follow:1. Hydraulic pump concrete, which is different from common building and industry building pump concrete, has both the characteristic of hydraulic concrete and the performance of pump concrete. Basing on the practical characteristic of project linear structure, the paper did technology economics compare between plans and select correctly box culvert pump concrete construction technique. On the basin of the selected technique, the article explored the need of raw materials of pump concrete and the characteristic of pump flyash concrete.2. The paper focused on the studying of mix proportion optimum design of hydraulic pump concrete. Firstly, this research checked and measured the raw materials, designed concrete mix proportion optimum according to concrete mix proportion design principles, method and steps, and compounded 19 kinds of concrete mix proportion, so the relationship between the amount of flyash and intensity and the relationship between ratio of water to glue and intensity can be summarized. Next, this research did some test on concrete performance indexes for studying the performance indexes of flyash pump concrete. Adding flyash to concrete can not only increase concrete quality, improve concrete performance and reinforce the enduring of concrete, but also reduce project cost and increase concrete performance indexes.3. Considering the serious destroy of alkali aggregate reaction, internal and foreign experts in this field pay much attention to aggregate alkali activity. The northern part of the project is near to Swallow Mountain, which is the main source of sandstone material. Swallow Mountain contains plentiful alkali activity material. In consideration of the importance of project, we did some systematic test study on reaction between concrete alkali and material. Thus, reasonable settlement can befound: adopting low cement in which the content of alkali is smaller than 0.6 %( calculate by sodium);adding some amount of flyash to concrete and so on. Because admixture can primely restrain alkali aggregate reaction, flyash should be added to concrete.4. Because of the demand of time limit and quality of the riverhead defending project of leading Luan River to Tianjin, it is very crucial for carrying out successfully this project to find optimum construction plan. Pump concrete, a fast job speed and high mechanization construction technique, is now usually applied in high-profile construction in industry and civil structural engineering. If this technique can be used in large-scale hydraulic project construction, it will be the breakthrough in both construction technique and concept. The paper studied pump concrete construction technology and expatiated on concrete mill technique, concrete transportation technique and calculate method of concrete discharged quantity, sendout and pump quantity in the view of construction. At the same time, the article designed concrete pump disposition and pump pipe confection in formal construction, explained the method of stopping pipe from plugging and the measure after plugging pipe, which has reference meaning to pump concrete construction.