ANALYSIS OF WATER-PIPE COOLING IN THIN-WALLED CONCRETE STRUCTURES

The appearances of cracking in concrete during the constructions of pier-wall structures, such as in sluices, aqueducts, culverts under floor, ship lock, overflow guidance wall and so on, are common and difficult to prevent. This paper aims at the mechanism and propagation course of the cracking. The basic difference of the temperature, the internal and external temperature difference and the shrinkage deformation of concrete are considered as the main factors influencing the phenomena. The cracking in concrete at early age is especially caused by the temperature differences. Therefore, the water-pipe cooling technique is an effective measure to decrease the temperature in the internal center of the structures. In doing so, the difference of the internal and surface temperatures is reduced and the appearance of cracking is avoided. A numerical algorithm is proposed in the paper to solve the resultant thermal problems including water-pipe cooling. An in-situ test about the influence and effectiveness of the present measure for prevention from cracking in piers of a sluice is studied. Some suggestions about to the application of water-pipe cooling to concrete structures are given.