The Analysis And Research On The High Performance Fair-faced Concrete

At preasent the high performance concrete is the main heading in development of concrete.Furthermore some foreign experts purport that it is the 21 century of concrete.Due to the high performance concrete have many excellent technical charcateristics which especially serves on the pile architectures,bridges and other structures that are exposed on the atrocious conditions,which accord with the use of qulification and performance of the fair-faced concrete.In our country,fair-faced concrete are ofen applied on bridges ,hydraulic structures and so on,which require the surface of concrete without stuck expose on the atmosphere.The fair-faced concrete require the appearance quality and durability of the concrete are highly enough,and it is just accord with the high performance concrete.This paper studied the combined performance of the both high performance concrete and fair-faced concrete in theory and practice. And that will make the performance concrete meet the requirements for the appearance from design to construction,and expecte this research can promote the development of construction technique of fair-faced concrete.Depends on the materials and construction conditions provides by the Chongqing XinPaiFang Interchange Modification Project items department,and the test equipments of Chongqing Jiaotong University, this paper collected many reference literature ,referred to other technology standards and engneering instances , carried on massive experimental studies for the research and taked part in an engineering construction project.This paper mainly summarized the data of tests and the construction technology of high performance fair-faced concrete,it also researched the durability and construction control measures of appearance quality of concrete.First,the paper analyzed work bility of fresh concrete and surface durability of high performance fair-faced concrete.Secondly,this paper studied the work perfermance as well as inflence factors of fresh concrete and the strength as well as durability(includes penetration resistance,anti-freezing feature,resistance of salt substance attack, resistance of sulfate attack) of hardening concrete,through scanning electricity physics test analysis, it also studied the performance characteristic from the microscopic level.The paper particularly illustrates the quality control measures of the high performance fair-faced concrete from raw materials choosing, proportioning,construction technology and so on ,with the exception of this ,it discussed the factors influenced appearance quality of concrete from formwork engineer,steel engineer,concrete casting and other aspects,in this part ,it also intruduced the maintenance and defect mending technology of concrete. In the end ,according to the engineering practicly experiments ,referenced correlative technical specification ,the paper brings forward the acceptance criteria of the fair-faced concrete,in order to guiding and regulating the construction of the fair-faced concrete. At last,the subject group finished the project—Chongqing"Technical specification for fair-faced concrete construction of municipal engineering(DBJ/T50-073-2008)"as a local standard.