The Application Of Construction Technology For Shrinkage Compensation Concrete In The Subway Station

The underground space of central business district of economic and technological development zone in the south of Changchun city is an important transportation junction,including subway line 1,line 6,city underpasses,underground parking and business development.The whole structure of this project is based on reinforced concrete materials,which usages are about 0.3 million cubic meters.This project belongs to typical structure of reinforced concrete in the underground project,which has relatively higher requirements to the waterproof capability.The harmful cracking is the main problem for the general reinforced concrete when this kind of material used in large size reinforced concrete structure,which will adversely affect structure safety.According to the requirements of GB 50108-2008 rule in Technical Code for Waterproofing of Underground Works,42 days after pouring concrete in both sides,post-cast strip can be worked.Therefore,the traditional construction of post-cast strip drags the whole construction process greatly.According to the researches,blending expending agents into general reinforced concrete can improve the compactibility of reinforced concrete structure,as well as increase the impermeability of reinforced concrete,which can effectively restrain the generating of harmful cracking.Meanwhile,using expansion reinforcing band substitutes traditional post-cast strip can avoid the second pouring concrete,shortcutting construction period.This article introduced the principle function of shrinkage-compensating reinforced concrete,and illustrated its impermeability and anti-crack function through theoretical calculation.Meanwhile through experiments,the writer found the optimal ratio of expanding agents in reinforced concrete for different intensity levels.This article also researched the application of shrinkage-compensating reinforce concrete in central business district underground project,and introduced the manufacture method of expansion reinforced bands.Incorporating the pouring concrete situation in a real way,the advantages of using shrinkage-compensating reinforced concrete can be displayed in the constructing process.Meanwhile,the reasonable constructing order and arrangement can also conduct the project in the future.According to the researches,blending expending agents into general reinforced concrete can improve the compactibility of reinforced concrete structure,as well as simplify the constructing procedures leading to reduce expected period.