Use of non-destructive testing for the evaluation of the preservation state of Iquique Clock Tower, Chilean Historic Monument

Abstract

The Clock Tower, a typical expression of the saltpeter period, is located in Arturo Prat Square in Iquique, Chile. The building, completely made of wood, has endured the passing of time without major modifications. There is concern about its conservation state. However, there are no records of in-depth evaluations that determine its conservation state. The present study, carried out through the use of non-destructive testing (NDT), is an evaluation of its current state. Basic inspection and structural analysis were also included. The results indicate that the wood of the building corresponds to the species Pseudotsuga menziesii (Oregon Pine). The basic inspection does not reveal any significant damage. However, there is evidence of attacks by insects in the larval stage, social insects and brown rot fungi. Abiotic deterioration by defibering is also observed. NDT studies—ultrasound, resistography and xylo hygrometry—allowed the estimation of density and static modulus of elasticity (MOE) in bending. The low density of wood is shown in a static MOE value of only 4.4 GPa. According to Chilean regulations, wood elements were classified as structural class F3. However, the structural analysis determined that the working stresses did not exceed the admissible stresses. At the foundations level, it is necessary to perform intervention actions.