Material Experimental And Technology Researches On Duct Grouting

With the development of prestressed concrete technology，prestressed concretestructure has been immensely applied in the project. As the extremely importantconstruction technology process in post-tensioning method prestress structure, ductgrouting has attracted lots of Scholars and engineering personnel attentions. Onceduct grouting incurs problems，the structure safety、durability and reliability willbe in danger during the using ages. Based on the bridge engineering of Nanning loopfreeway，this article mainly discusses the performance of grouts and its groutingtechnology.Through researching on papers home and abroad , laboratory testing, theoreticalanalysis and engineering experience , this paper has deeply researched the technologyof duct grouting with post-tensioning structure. The main contents include: the rawmaterial-selecting and technology assessment、the new mixed grout`s performancetest(fluidity、free bleeding rate and expansion ratio、filling volume、flexural andcompressive strength)、the orthogonal design of optimum mixture ratio、the influenceon size performance of temperature and humidity and mixer speed、the anti-corrosioncapacity test as well as duct grouting techniques and quality control standard.At first, the paper analysis the raw materials(cement、grouting material and water)of Nanning loop freeway, use HR cement calculation on working performance ofvarious grouting materials. Then, optimum mixture ratio and optimal raw materialswere determined based on variance analysis method and orthogonal test whichcontains of 3 factors and 3 levels. mixing these optimal raw materials with optimummixture ratio, research and verification temperature、humidity、mixer speed、accelerated corrosion test how to affect size performance under certainenvironmental conditions, recommend for the best choice to duct groutingconstructions. Finally, combined with the field experimentation research in realproject, construction cautions and quality control points are introduced in detail,through detection results the article carries out a comprehensive evaluation andanalysis on duct grouting quality.Experimental study shows that quality status of duct grouting can obtain reliableguarantees if we choose proper raw materials、determine optimum mixture ratio、paymore attention to the adverse effect of the external factors、master correct constructionmethod. Thus, various engineering hidden dangers will no longer exist in prestressedconcrete structure.