Kensho Hirao

• Tokyo Institute of Technology

Recently, inorganic zinc-rich paints have been increasingly applied to the faying surfaces of high-strength bolted friction joints. The coating thickness of the faying surface is said to affect the slip coefficient of the bolted joint. If the coating thickness on faying surfaces of bolts in existing joints can be measured without disassembly the jo...

Bolt axial force of high-strength bolted joints decreases due to deterioration. One of the conventional methods to evaluate the bolt axial force is ultrasonic testing. However, quantitative evaluation of the bolt axial force is controversial in terms of accuracy, and some problems remain for practical use. This study attempts the accurate evaluatio...

p>It has been confirmed that bolt axial force of high-strength bolted joints decreases due to various effects. Generally, evaluating the bolt axial force of existing bolts has been an important issue. In a conventional ultrasonic bolt axial force evaluation method, bolt length change due to the change of bolt axial force is evaluated. However, bolt...

In frictional type pretensioned bolted joints, one specification is employed for contact faces in each joint in principle. Meanwhile, in some cases such as protection works of existing bridges and fabrication of box girders made of weathering steel without coating, introduction of usage of different contact faces in one joint might often allow labo...

This study evaluates internally present flaws in RC deck using Ultrasonic Testing. The ultrasonic waves are input from the surface of the asphalt pavement. Wavelet analysis with original mother wavelets CRMW successfully emphasizes the location of the horizontal cracks in the RC deck. The original wavelets are developed by the reflected waves from...