In situ assessment of structural timber using semi-destructive techniques

Abstract

This paper summarizes the test recommendations for selected semi-destructive testing techniques as developed by members of the RILEM Technical Committee AST 215 "In-situ assessment of structural timber". The recommendations cover resistance drilling, core drilling, glue line test, tension micro-specimens, screw withdrawal, and several hardness tests. The paper includes a matrix of common non-destructive testing to assess structural timber. The discussion of each technique is intended to provide users with sufficient information to understand the theoretical basis, typical equipment set up, and basic capabilities and limitations

Research on residual bending capacities of used wood members based on the correlation between non-destructive testing results and the mechanical properties of wood

“…Lee et al (2014) assessed the residual performance of partially charred components of an old wooden structure by ultrasonic velocity testing and by measurement of drilling resistance. Tannert et al (2014) summarized the test recommendations for selected semi-destructive testing techniques including resistance drilling, and provided users with sufficient information to understand the theoretical basis, typical equipment set up, and basic capabilities and limitations for such tests. Jasieńko et al (2013) proposed that resistance drilling techniques are suitable for detecting internal defects, decay, and cracks, determining the location and dimensions of degraded areas, and assessing the mechanical properties of structural timber members.…”

Nondestructive Evaluation and Reliability Analysis for Determining the Mechanical Properties of Old Wood of Ancient Timber Structure

“…In addition, some research (Rinn et al 1996;Acuna et al 2011;Kahl et al 2009) proposed that a drilling resistance test could provide good prediction for wood density. As reported by Jasieńko et al (2013), Tannert et al (2014), and Zhang et al (2015), the drilling resistance test also could detect the internal defects, cracks, and decay, and determine the size and location. Feio and Machado (2015) and Probett et al (2013) investigated the relationships between dynamic modulus of elasticity of specimens and modulus of elasticity, bending strength, and ultimate compressive strength parallel to grain by stress wave timing combined with resistance drilling tests.…”

Inspection and condition assessment of existing timber structures

“…These include acoustic, electro-magnetic, thermal and optical methods, as well as mechanical techniques [6,11]. In this section, the majority of NDTs and semi-destructive methods for assessing the existing timber structures are listed, and the most common ones are briefly explained.…”

“…Dietsch and Kreuzinger [2] summarized the most common methods: visual (hands-on) inspection, tapping (sounding), mapping of cracks, measurement of environmental conditions, measurement of timber moisture content, endoscopy, penetration resistance, pull-out resistance, drill resistance, core drilling, shear tests on core samples, stress waves, X-ray, dynamic response, load tests (proof loading), strain measurement, microscopic and chemical laboratory methods, macroscopic laboratory methods -testing of specimen. Tannert et al in [6,7] explained several new techniques such as the infrared thermography, glue line test, screw withdrawal, radial cores to determine compressive strength, pin pushing and surface hardness. The last step in the assessment of timber structures is to incorporate the assessed data into probabilistic models that will be used to calculate the remaining capacity and reliability of such structures.…”