The effect of post-fire-curing on strength–velocity relationship for nondestructive assessment of fire-damaged concrete strength

Integrated Approach for Post-fire Reinforced Concrete Structures Assessment

“…These techniques can produce a detailed set of data related to the mechanical characteristics of materials, see for example [21][22][23][24] and [40][41]. In particular, the velocity of ultrasonic transit pulses in undamaged concrete can reach and exceed 5000 m/s, see [22].…”

“…With the aim of presenting a general procedure for RC assessments after fire, in this work several methods are presented and tested referring to an interesting real case-study: visual examination, destructive and non destructive tests like pull out, sonic and ultrasonic test, sclerometer and SonReb test (see for example [21][22][23][24]) can produce a detailed set of data related to the mechanical characteristics of materials. Other effective techniques capable of determining fire damage on concrete are: microscopic analysis (optical and electronic), see [25][26][27][28][29][30][31], Thermogravimetric analysis (TGA), combined with Differential Thermal Analysis (DTA), see [32][33], X-ray diffractometry (XRD), see [34][35] and colorimetry, see [31], [36][37][38].…”

The use of surface coating in enhancing the mechanical properties and durability of concrete exposed to elevated temperature

“…In addition, Lin et al found that, after recuring in the air for 6 months, the residual compressive strength of air-cooled concrete exposed to 600°C was only 28% of the original strength [13]. However, the residual compressive strength of concrete with SCC increased from 51% to 64%.…”

“…It is now realized that the fire-damaged concrete could regain part of the properties with post-fire-curing due to the rehydration of the C-S-H gel [8][9][10][11][12][13][14][15]. The heating temperature and the recuring conditions were considered as the main influence factors on the recovery of concrete exposed to elevated temperature [8,9].…”

“…The heating temperature and the recuring conditions were considered as the main influence factors on the recovery of concrete exposed to elevated temperature [8,9]. Most researchers concluded that water played an important part in the rehydration of concrete exposed to elevated temperature [10,13,14,16].…”