Health assessment of concrete structures by resistivity testing and electric imaging | |
| Author | Narongchai Wiwattanachang |
| Call Number | AIT Diss. no.ST-12-02 |
| Subject(s) | Electric resistors Concrete Testing |
| Note | A dissertation submitted in partial fulfillment of the requirements for the degree of Doctoral of Engineering in Structural Engineering, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Series Statement | Dissertation ; no. ST-12-02 |
| Abstract | This study proposes an innovative of engineering geophysical tools to assess concrete health and monitor crack development in concrete structures utilizing resistivity testing and electric imaging techniques on laboratory and field testing. Possible correlations between electrical resistivity, compressive strength, permeability and porosity of concrete samples were investigated. During curing the increase in resistivity and compressive strengths were identified. Several empirical relationships were found and used to assess mechanical and hydraulic properties of concrete to understand pore structure development and the hydration process of hardening concrete. A comprehensive experimental program was designed and conducted to measure electrical resistivity and other properties on concrete sample in the laboratory. The study also presents results of application of electrical imaging to monitor crack development in fiber concrete beams. Artificial cracks and those developed during a four-step loading test were investigated. Mini-electric imaging was conducted to detect presence of internal cracks. Resistivity measurements were influenced by high-resistivity in the surrounding air. This study provides innovative procedures to correct resistivity measurements due to beam size effect based on results from 3D resistivity forward modeling and inversion was proposed and successfully applied. Results showed that both crack direction and depth could be determined by inversion of resistivity data. A notable application of this study is to use resistivity testing and electric imaging to assess the concrete structures before and after the gigantic flood in 2011 at five locations in Pathum Thani province, one of the most heavily flood affected provinces in Thailand. The results showed that the rebound value, resistivity, and compressive strength are to decrease but the effective porosity is to increase after the flood. The older concrete structures tend to deteriorate more than the younger concrete structures. |
| Year | 2012 |
| Corresponding Series Added Entry | Asian Institute of Technology. Dissertation ; no. ST-12-02 |
| Type | Dissertation |
| School | School of Engineering and Technology (SET) |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Structural Engineering (STE) /Former Name = Structural Engineering and Construction (ST) |
| Chairperson(s) | Pham Huy Giao; |
| Examination Committee(s) | Pennung WarnitchaiWorsak Kanok-Nukulchai; |
| Scholarship Donor(s) | Rajamangala University of Technology Suvarnabhumi, Thailand; |
| Degree | Thesis (Ph. D.) - Asian Institute of Technology, 2012 |