C1 C40 5 —

C2 C40 5 Strengthening using two layers of  textile

first, then corrosion 5%

C3 C40 5 Corrosion 5% first, then strengthening

using two layers of  textile

C4 C40 10 —

C5 C40 10 Strengthening using two layers of  textile

first, then corrosion 10%

C6 C40 10 Corrosion 10% first, then strengthening

using two layers of  textile

C7 C40 15 Corrosion 15% first, then strengthening

using two layers of  textile

© ASCE 04016231-2 J。 Struct。 Eng。

Fig。 1。 Specimen size and reinforcement  detailing

Table 2。 Mechanical Properties of Steel  Bar

The weft fiber (carbon) yarns of the textile were kept parallel to the circumferential stress direction, and then another layer of fine-grain concrete was applied onto the surface of the textile。 These steps were repeated to provide two layers of reinforcement。 The specific information  of  the  specimens  is  given in  Table  1。 In  this  test,

Steel Bar

Fig。 2。 Textile

by comparing Specimens C1, C2, and C3 (or Specimens C4,   C5,

and C6) in the same corrosion environment, the effect of the TRC reinforcement and the reinforcement method of corrosion after reinforcement or reinforcement after corrosion were  studied。

Corrosion Method

The columns were wrapped with wire mesh before corrosion。 The mesh was set as a negative pole by applying wire, and the specimen longitudinal bars were set as the positive poles。 The test used a rel- atively high hygroscopicity sponge to wrap the columns, on which was wound a layer of plastic film。 It was necessary to keep the sponge underwater for 3–5 days before switching on the direct cur- rent (DC) power, which was predetermined as 1。2 A。 Based on the results of other researchers and the previous findings of the authors’ workgroup, the length of the electrified time test was suggested to be enlarged to 1。4 times the theoretical values, which are 15 days for 5% corrosion, 30 days for 10% corrosion, and 45 days for 15% corrosion。 According to Ma et al。 (2012), Faraday’s law can be applied to the electrochemical method for rapid corrosion of the reinforcing steel bar。 The corrosion ratio, which is the ratio of the steel corrosion mass to the total mass of the steel bar in the corroded section, can be controlled by controlling the current in- tensity and electrification time。 The test used a 5% concentration of salt water to wet the sponge regularly to ensure that it was wet throughout the test。 All of the corroded columns were subjected to the same corrosion process in the period of corrosion。 In this test, by comparing Specimen C2 and Specimen C5 (or Specimens C3, C6, and C7) with the same reinforcement method, the effect of the different corrosion ratios on the seismic capability of the RC col- umns was studied。

Material Measurement

Concrete