The TLS, a laser measuring tool used to detect deterioration within architectural structures, was used by researchers from the University of Salamanca to assess the state of the city walls of Ávila. The recently-invented system is used in monument maintenance work, above all on structures built centuries ago.
“The laser takes a very quick reading of the structure, from which we obtain a three-dimensional image,” Diego González Aguilera, co-author of the study published in the journal Nondestructive Testing and Evaluation, and an engineer at the University of Salamanca, told SINC.
The work began with data collection. This involved the researchers measuring the Ávila walls in situ, specifically the belfry of the Puerta del Carmen gate, using a TLS. “This scanner emits a laser beam which bounces off the monument and returns to an internal sensor, measuring the distances between each point of the wall,” says the expert, adding that “the laser beam sweeps the entire surface of the monument”.
The TLS takes two measurements, one of the inside part and the other of the outside of the walls, using 1.5 million and 2.5 million points, respectively. “These data are then analysed in the laboratory, where algorithms are used to create a 3D representation of the surface of both sides,” says the researcher.
“One measurement alone is not enough to evaluate damage, however,” adds González Aguilera, “because each must be compared with previous or later samples.” In this study, the researchers collected data at a six-month interval, because “the further apart in time the samples are taken, the greater the changes that can be observed”, he explains.
This allows two types of architectural pathologies to be picked up: collapse, which is a wall’s loss of verticality, and complete movement of the wall itself. The engineer points out that “the two sets of data and the amount of information collected must correlate in order for the results of the study to mesh together properly”.
Other methods besides the TLS are used in to evaluate architectural structures. “The most classic is the theodolyte system to measure topography, although there are also other tools such as GPS,” explains Aguilera. This study used the TLS because it is a new system that does not damage a structure and “it had to be tested in a complex situation”.
SINC Team | alfa
Flexible protection for "smart" building and façade components
30.11.2016 | Fraunhofer-Institut für Silicatforschung ISC
Healthy living without damp and mold
16.11.2016 | Fraunhofer-Gesellschaft
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
08.12.2016 | Life Sciences
08.12.2016 | Physics and Astronomy
08.12.2016 | Materials Sciences