A Method for Instant Estimation of the Temperature Experienced by Fire-Damaged Reinforced Concrete Structures Using Titanium

Abstract

When a concrete structure is exposed to fire, its structural safety is significantly compromised due to the spalling of members and scaling of concrete. In addition, its durability is substantially reduced due to certain chemical changes such as the dehydration of Ca(OH)2, the main hydration product of concrete, and the rehydration of CaO. Therefore, when fire damage occurs to a reinforced concrete (RC) building, rapid diagnosis and evaluation techniques are required for immediate repair and reinforcement, requiring a crucial step of quantitatively determining the heating temperature. This study aims to demonstrate a method of estimating the heating temperature experienced by fire damaged RC buildings. The experiments utilized two short RC column specimens with embedded titanium strips. The discoloration characteristics of titanium at high temperatures provided a quick, accurate, and simple mechanism for the estimation of the heating temperature by depth. Empirical equations were derived to estimate the heating temperature as a function of the discoloration characteristics of titanium. Thereafter, a comparison of this estimated temperature with the actual heating temperature measured using thermocouples revealed an average error of less than 20 °C, thereby demonstrating a significantly good correlation and an extremely high reliability of the proposed method.

Influence of Precursor Mixtures on the Laser Chemical Vapor Deposition of TiC Fibers

“…Consequently, this mixture change, even in the hydrogen-balanced condition, impacts the rate of axial growth. While the growth rate decreases, the fiber-to-fiber growth rate variation did reduce, albeit a modest decrease in Titanium oxide is known to exhibit a bronze color at low temperatures and a white color at higher temperatures [34]. The hydrogen-balanced (1:1) fibers exhibited a varying temperature gradient as it deposited, which was visible in Figure 7a, and where such thermal gradients would have created convective motion of the gases around the fiber that would lead to the oxidization of titanium.…”

Effects of the application of low-temperature atmospheric plasma on titanium implants on wound healing in peri-implant connective tissue in rats

“…We set the time for plasma application to 30 s, which seems appropriate for the chair side of clinical dental treatment. Ti shows discoloration owing to the formation of an oxide film on the surface at high temperature [ 35 ], which suggests that a handheld plasma device is a useful tool for adding hydrophilization on Ti disks without discoloration. Our results showed that the handheld plasma device had no effect on the roughness of the Ti surface.…”

Repairing Materials for Different Post Fire - Damaged Structural Concrete Members: A Critical Review

“…The compressive strength of concrete can decrease by up to 50 percent if the concrete is exposed to 600 °C. When concrete is exposed to fire for a long period, the concrete strength is reduced [2,3]. Also, the reinforcement steel strength inside the concrete was reduced [4].…”