Research On The Performance Of The Concrete Used To Repair The Canals

Since the founding of the PRC, lots of water channels, bridges, pumping stations and other hydraulic concrete construction were constructed For the long-term physical, chemical and biological effects, the aging problems of these buildings become more and more serious. And this had affected the normal use of the structures. Therefore, to repair these concrete structures can improve the performance and prolong the service time of the concrete structures. Besides, they can protect the environment and have significant economic and social benefits too.The main purpose of this paper is to use the MA modifier, UEA-IV expansive agent and polypropylene fiber to modify the common concrete, and make it have good strength, bond property and durability as to repair the hydraulic and general civil concrete. The main work is as follows:(1) Study the modified concrete’s basic mechanical properties and the associated mechanisms by the compression test and splitting tensile strength test.(2) Study the modified concrete’s durability and the associated mechanism by the carbonation test and permeability test.(3) Study the modified concrete’s bond property and the associated mechanisms by the New and Old concrete’s splitting-tensile test and the New and Old concrete’s permeability test. In addition, the way about the New and Old concrete’s permeability and the way about the interface’s treatment is discussed.(4) Use the environmental scanning electron microscope to observe the micro structure of the modified concrete and explain the related mechanisms.The research results can be given out as follows:(1) MA modifier can form a continuous film that mixed with the cement’s hydrates and form network in the concrete, reduce the concrete’s internal defects, increase the concrete’s density, toughness, anti-seepage, anti-carbonation properties and so on.(2)The UEA expanding agent mixed into the concrete can generate large amounts of ettringite crystals by the hydration reaction which can fill the tiny pores of the concrete and to improve the concrete’s density, compressive strength, anti-seepage, anti-carbonation properties and so on.(3) Polypropylene fibers can make the concrete maintain higher moisture content, hydrate more full in the early time, and reduce the crack numbers in the concrete so as to mitigate the stress concentration.(4) When the MA was mixed with18%, UEA-doped12%, polypropylene fibers was mixed with1.1Kg/m3, the modified concrete has the best bond property and durability.(5) Infiltrate the concrete enough before the repair, can improve the repair quality obviously.