A study for the effects of the electrochemical deposit method on the reinforced concrete properties

• Main Authors: Cin-Wei Syu, 徐勤威
• Other Authors: Wei-Chung Yeih
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/51988045178761847500

碩士 === 國立臺灣海洋大學 === 河海工程學系 === 95 === The concrete material could suffer from cracks, partial damage and embedded rebar’s corrosion once the internal and/or external hazard factors become harmful. As such deteriorations act over a sufficiently long period, they will cause functions of concrete reduce econtinuously. It is not trivial to study the repair methods. This research uses the electrochemical deposit method to heal cracks. This study not only investigates deeper of the electrochemical deposit method based on the previous research but also the efficiency of repairing the crack using different electrolyses by using mechanical tests, physical property tests and influence on the corrosion of rebar. Results show that the air entraining agent concrete has more voids when the AEA/C is higher. After repair, compression strength increases as the repair time of electrochemical deposit treatment increases. For concrete specimens with AEA/C equal to 0.025 % and age of 56 days, the compression strength recovers to 19.29 MPa after repair, which is close to the compressive strength of the OPC control specimens (W/C = 0.7). Through the X-ray diffraction, the white deposit is confirmed to be ZnO. In addition, the EDS analysis shows that the electrochemical deposit piles up in voids and cracks inside the body from interior region near cathode. The efficiency for using different solutions is also investigated. The previous study showed that using ZnSO4 as the electrochemical deposit solution may raise a little bit of bending strength while comparing with the unrepaired one. Our results show that using CaSiO4 as the electrochemical deposit solution to repair cracked concrete with crack width of 0.4 mm, the bending strength achieves to 22.63 MPa after 8-week treatment. This made the recovery on bending strength up to 99.69 %. After repair, some specimens are subjected to the accelerated corrosion using anodic current then the bendin tests are carried out to investigate the efficiency of two electrolyses on the corrosion prevention capability after repair. The electrochemical deposit can make concrete suface denser and reduce permeability, it prevents the harmful factors from invading the concrete. Because of that, the decrease in bending strength of the repaired concrete beam is less significant than the unrepaired one.