Deterioration of Pracana Dam due to ASR. Main features and repair works

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:192170

Matos, D S; Camelo, S ^[1]; Silva, H S; Pinho, J S ^[2]

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1. HIDRORUMO, EDP, Porto (Portugal)
2. LNEC, Lisboa (Portugal)

Some of the Portuguese concrete dams show evidences of ASR. In majority the phenomena is still benign. However, in a few cases some significant deterioration of ASR type have malfunctions arose. In such cases deteriorations of ASR type have been detected while in the others the ASSR type prevail, depending on the type of aggregate. The paper reports the most important case of ASR in Portuguese concrete dams. Pracana dam is a buttress structures built in 1948-51, being the aggregates predominantly of quartzitic and metapellitic nature. Subsequently to the intense fracturing due to a quick concrete cooling during the first filling of the reservoir, high levels of expansion rates had been detected by means of monitoring system. After 8 years emptied reservoir, rehabilitation works took place in 1991-92 aiming at the concrete mass regeneration and the installation of an upstream face membrane, the improvement of spillway capacity and of the foundation performances. The behaviour of the dam as well as the performed tests (petrographic, mechanic, ultrasonic and expansibility ones) and repair works are described in the paper.

• OSTI ID: 192170
• Report Number(s): CONF-9510182--
• Country of Publication: United States
• Language: English

Related Subjects

13 HYDRO ENERGY
CHEMICAL REACTIONS
CONCRETES
DAMS
HYDROELECTRIC POWER PLANTS
HYDROXIDES
PORTUGAL
REPAIR
STRESSES