Structural health assessment of fire damaged building using non-destructive testing and micro-graphical forensic analysis: A case study

Models for compressive strength estimation through non-destructive testing of highly self-compacting concrete containing recycled concrete aggregate and slag-based binder

“…The specimens were stored in a moist room (95 ± 5% humidity and 20 ± 2 °C temperature) to achieve optimum strength development. Three days before each age testing, the specimens were exposed to the laboratory environment (60 ± 5% humidity and 20 ± 2 °C temperature), to obtain a completely dry concrete surface [2]. The real conditions of the structure when its compressive strength is indirectly estimated were thereby simulated [3].…”

“…The highly accurate models described in the previous sections, to predict compressive strength through the hammer rebound index or UPV analysis of a SF3 class SCC, mean that the composition effect of the mix may be disregarded for the prediction of SCC strength [69]. Nevertheless, the use of a single indirect measure can lead to incorrect strength estimations, due to a wide variety of reasons, from poor calibration of the device used to occasional irregularities within the concrete [2]. The best solution to this problem is to use models with two variables (hammer rebound index, and UPV) to estimate the strength, although they have the disadvantage of complexity and their implementation is difficult [1].…”

“…Traditionally, non-destructive tests have been used to estimate the compressive strength of concrete [1] in rehabilitation works [2], and for the estimation and monitoring of concrete strength during construction and throughout the lifecycle of the structure [3]. The oldest and the most common methods are the so-called indirect measures: the hammer rebound index, which is based on the surface hardness of the concrete [4], and Ultrasonic Pulse Velocity (UPV) analysis, which depends on the microstructure of the material [5].…”

“…Even though these indirect measures have long been employed, their progress in relation to their use and application in construction has been remarkable since 2000 [19]. Some new trends in this field include their successful use at evaluating the compressive strength of concrete at early ages [20,21], to study the spatial variability of concrete strength [22,23], especially in beams [24], and high-precision detection of micro-cracking within the damaged concrete [2,25], especially with UPV analysis [26]. In addition, there is also a field of research regarding their applicability in concretes made with alternative materials [27,28], and in nonconventional concretes, such as high performance fiberreinforced concrete [29] and Self-Compacting Concrete (SCC) [30].…”

A Review of Precast Concrete Beam‐to‐Column Connections Subjected to Severe Fire Conditions

“…e specimens of damaged concrete and reinforcing bars were tested to determine their residual strengths. Aseem et al [61] assessed the residual durability properties of the reinforced concrete structural column and shear walls using an NDT and determined their residual mechanical properties using core extraction tests. e results of microstructural and thermal analyses were used to develop a framework for estimating the exposure temperatures of the various structural units.…”