05/12/2022
By Sokny Long

The Francis College of Engineering, Department of Civil and Environmental Engineering, invites you to attend a master’s thesis defense by Nimun Nak Khun on “Concrete compressive strength monitoring using ultrasonic, pulse tomography, and ground penetrating radar.”

Master’s Candidate: Nimun Nak Khun
Thesis Defense Date: Monday, May 23, 2022
Time: 2 to 3:30 p.m. EST
Location: This will be held remotely via Zoom. Those interested in attending should contact nimunnak_khun@student.uml.edu and committee advisor, tzuyang_yu@uml.edu, at least 24 hours prior to the defense to request access to the meeting.


Thesis Committee:

  • Tzuyang Yu (Chair), Professor, Civil &Environmental Engineering, UMass Lowell
  • Susan Faraji, Professor, Civil &Environmental Engineering, UMass Lowell
  • Jianqiang Wei, Assistant Professor, Professor, Civil &Environmental Engineering, UMass Lowell

Abstract:
Quality control during the construction phase is very important especially in developing countries where skilled workers are scarce, construction technologies are limited, and construction law and regulation are poorly implemented. The quality of construction determines the sustainability, durability, and service life of a building or infrastructure. Good quality construction can extend the service life of concrete structures, save rehabilitation costs, and prevent structures from catastrophic failures. The development of remote sensing technologies has helped structural engineers to conduct nondestructive testing and evaluation (NDT/E) on concrete structures. NDT/E can assess the quality of the construction with great accuracy compared to traditional practices such as visual inspection and rebound hammer. In this research, the use of Pulse Tomography sensor (PT) and Ground Penetration Radar (GPR) to monitor compressive strength development concrete panels (12"x12"x5") casted with two different water-cement (w/c) ratio. The PT sensor (Ultrasonic pulse-echo, Bandwidth= 35-40 kHz, Proceq Pundit 250 Array) and one GPR (GSSI StructureScan Mini LT, Antenna Frequency= 1600 Mhz) was used for data collection, MATLAB was used in processing subsurface images of the concrete specimens. Interpretation of PT and GPR images is per- formed together with ultrasonic testing and concrete compressive strength test. This research indicates the relationship between the compressive strength development of concrete specimens with the ultrasonic pulse velocity (Vp), shear wave velocity (Vs), dielectric constant (𝜖′𝑟), and the calculation of effective dielectric constant inside concrete.

All interested students and faculty members are invited to attend the online defense via remote access.