Reason Analysis And Solution For Unusual Damage Of The Steel-Concrete Bridge In Coastal Region

The armored concrete bridge in Coastal region bears the abominable marine climate environment and sea water to corrode for a long time, receive carbonization, chlorine salt of concrete constantly, sulphate corrode to concrete and rivers is being eroded, the machinery one collides and so such physic moment, far from reaching the design service life of the bridge, the damage that influences its security to run seriously has appeared in the bridge, call this damage as the unusual damage. The unusual damage has proposed the requirement for safe, economic and high durability to the armored concrete bridge.Baised on the foundation of possible corrosion factor analysis of unusual damage of the Fujia bridge , and make it as a example, to issue the unusually damaged reason happens to the bridge in Coastal region; and issue the measure prevented from rottenly about how to improve the concrete density of the bridge and durability.About the armored concrete highway bridge in Coastal region, the primary reason for unusually damaged in the bridge is the corrode from salt of chlorine. The too high content of the chlorine salt destroys the oxide film of the reinforcing bar, in case of invade in moistur, it will cause the corrosion on condition; the corrosion of reinforcing bar causes the concrete ofsplitting bloatedly, it is the bloated concrete that put in the harmful mediums such as the moisture contains high quantity chlorine. The splitting bloatedly of concrete accelerates the corrosion of the reinforcing bar greatly, during circulation, will be very difficult to control the situation.The science of bridge building in Coastal region should be standardized by the regulation of currently in our country and carry on the design and operation of durability, employ the high-performance concrete actively, and we should strictly observe the key technical, such as the content of chlorine, and the minimum thickness of antiabrasion layer in. The most economic reasonable and effective basic measure which prevents from reinforcing bar icorroded is to usd the high-performance concrete. To select the good raw materials, and to match ratio and design according to the prerequisite of formulating high-performance concrete designing intens require to carry on. The high-quality raw materials are foundations of preparing the quality concrete. Adopt high-efficient water-reducing agent (FDN) and compound superfine powder technology can obtain good work, concrete to glue person who gather mix and stir things, could pump sending construct, since no terms will be offered, it can last water glue of concrete, and also, to improve the density of the concrete, its comprehensive durability is got and improved prominently.While constructing. we should strengthen quality control, each side's subject does own duty, strengthen supervision, management, coordination. In the concrete constructs, from batching, mix and stir, transport, build, shake, smash, keep surface and process of maintaining etc, we must go on according to the operational procedure, and to improve density and anti-permeability of the concrete. About control measure of construction, we should strengthen raw materials quality and examine and measure the precision to control with the batching; Adopt and stir the homogeneous good pressure mixer with high efficiency to fully mix and stir, meantime guarantee mixing time, make high-efficient water-reducing agent in the even scattering of surface of cement particle. Fully shake and smash, adopt the high-frequency vibrator to shake and smash, so as to ensure the density of the concrete, for abundant maintenance, begin maintenance to the concrete earlier, sustain the wet maintenance for a long time, guarantee cement water reacts and reflects with the volcanic. The key position in the structure should go on the system, check, organize the middle of the agent structure to confirm, can't harm and measure and analyze the theory with dependability.In the actual project, whether the reinforcing bar depends on the concrete antiabrasion layer and reduces depth and density of the harmful ion permeate. To improve thickness and density of antiabrasion layer of reinforcing bar, is effective to postponing the time that the reinforcing bar begins the corrosion. If mix in the concrete with too much salt, will promote the corrosion of the reinforcing bar in the concrete. Especially after the concrete of antiabrasion layer fractures, the corrosion pace of the reinforcing bar is fast even more. So, in safeguarding on stage later, we should take the measure of repairing to the state of fracturing of antiabrasion layer in time, prevent the internal reinforcing bar. After the bridge comes into operation, we should set up, perfect the trial of strength and check, evaluate the system, periodically check the bridge in time, which should be including frequent one, fixed and special inspection, master its technological state systematically, in order to find the changes of flawed or damaged and relevant environments in time;after the question found, takes measures to solve the problem in time. The rational, fixed maintenance keeps the good performance to the bridge. It has essential function to lengthen the service time of the bridge.