[雙語翻譯]---外文翻譯--葡萄牙海洋環(huán)境中混凝土損壞的案例研究（原文）

1、Case studies of concrete deterioration in a marine environment in PortugalAnt? onio Costa *, J? ulio AppletonDepartamento de Engenharia Civil, Instituto Superior T? ecnico, Technical University of Lisbon, Av. Rovisco Pai

2、s, 1049 001 Lisboa, PortugalAbstractThe long-term behaviour of concrete structures has shown that their main cause of distress is reinforcement corrosion. One of the most aggressive exposure conditions for concrete is th

3、e marine environment. In these conditions chloride penetration and chloride- induced reinforcement corrosion rates can be very high, often leading to a reduced service life. This paper describes a series of case studies

4、of different types of concrete structures, subject to several exposure conditions in the marine environment, that suffered extensive deterioration due to chloride-induced corrosion. Several degrees of deterioration assoc

5、iated with different exposure conditions are described and different types of corrosion both in reinforced and prestressed concrete structures are illus- trated. ? 2002 Elsevier Science Ltd. All rights reserved.Keywords:

6、 Reinforcement corrosion; Concrete structures; Marine environment; Chlorides; Repairs; Docks; Wharves; Bridges1. IntroductionReinforced concrete has been in the last decades one of the most used building materials. It ha

7、s proved to be a reliable structural material with very good durability performance when properly used. However, there are many structures which show early deterioration, namely those exposed to aggressive environments.

8、Experience shows that the corrosion of the rein- forcement is the main cause of structural concrete de- terioration. This type of damage is responsible for the huge financial costs spent each year on the repair of deteri

9、orated structures. The main reasons for the poor performance of con- crete structures are poor workmanship and lack of knowledge of the deterioration mechanisms which result in insufficient planning and wrong estimation

10、of envi- ronmental effects. Nowadays, it is well known that the durability of materials and structures depends both on the environmental conditions at the exposed surfaces of the structures and on the material resistance

11、 to the ac- tion of aggressive substances. The understanding of these two main aspects is the key for the design and execution of durable structures and for the rational approach to the repair of damaged structures.This

12、paper presents some case studies where struc- tures exposed to the marine environment showed early deterioration due to reinforcement corrosion. In these case studies the causes of the poor performance of the structures

13、referred to above are well illustrated. Several degrees of deterioration associated with different expo- sure conditions are described and steel corrosion both in reinforced and prestressed concrete structures is illus-

14、trated. Repair strategies for extending the service-life of those structures are also presented in this paper.2. Case studies2.1. DocksThis example describes the deterioration of the docks of a shipyard located in the es

15、tuary of River Sado, in the west coast of Portugal. The shipyard has three reinforced concrete docks (docks 20, 21 and 22) built during the 1973–1975 period. Dock 20 is a ship construction platform with plan dimensions o

16、f 420 ? 75 m and 8 m high walls. Dock 21 is intended for ship repair and its dimensions in plan are 450 ? 75 m with 18 m high walls. Dock 22 is also intended for ship repair and its dimensions in plan are 350 ? 55 m with