The Problem
FPrimeC was retained by Gillespie Building Consultants Inc. (Client) to perform non-destructive evaluation and testing on three (3) upturn concrete beams located at the parking garage of a condominium building in Ajax, Ontario. Concrete elements under investigation were three (3) concrete beams at specified locations of the parking roof. At the time of inspection, extensive cracking was observed on the surfaces of concrete beams (inside and outside). The cracks were inclined and more frequent in number and severity near the supports (concrete walls). The main objective of the project was visual and non-destructive inspection of concrete beams at select areas; including map existing cracks, map location of transverse reinforcement, and measure width and depth of cracks.
Testing Methodology
A site visit and meeting with Client was performed to discuss the test areas and communicate project objectives. Following the preliminary site visit, a testing plan including (close-up) visual inspection of existing cracks, and non-destructive testing (NDT) on concrete beams was proposed.
Visual Inspection
The visual inspection involved arm-length inspection of cracks, and other potential surface defects. All major visible cracks and surface defects such as concrete delamination were marked for preparation of engineering drawings. A crack width gauge was used to determine the width of cracks at two locations along each crack (one at the top, and one at the bottom end). The cracks width and severity were determined according to the Ontario Structure Inspection Manual (OSIM, 2008) guidelines.
Non-Destructive Testing
On each concrete beam, further inspection and testing was performed in the test areas using nondestructive testing (NDT). Two (2) NDT test methods includingGround Penetrating Radar (GPR)andUltrasonic Pulse Velocity (UPV)were utilized in this project.
Ground Penetrating Radar (GPR)用于验证钢筋的位置和间隔。线扫描用于验证光束中的横向加强件（即镫形）的位置。在几个位置，进行测试以验证梁中央的纵杆的位置。
Ultrasonic Pulse Velocity (UPV)用于估计选择裂缝上的裂缝的深度，无论何处都可以裂缝。选择标准基于每个测试区域的类型，程度，裂缝宽度的严重程度。
Read More:
Ground Penetrating Radar – Concrete Scanning using GPR