To make roadway maintenance predictable, the Centre for Public Works Studies and Experimentation (CEDEX) installed a dynamic structural health monitoring system on the A-62 motorway in Valladolid, Spain. This monitoring system helps to establish predictive maintenance software models and address specific problems which can occur over life time. Starring in this project was HBM’s QuantumX and catman data acquisition and analysis system.
In February 2018, a continuous monitoring system was installed on a section of the A-62 motorway in the Spanish province of Valladolid. The stated target is to measure the bearing capacity of the right-hand lane and to avoid structural health problems that are caused by heavy vehicle traffic, material fatigue and weather influences.
Monitoring helps with understanding the character of the materials used, and not only facilitates rapid response to problems such as breakages and cracks but also helps with determining the root causes of damage.
The automated structural health monitoring system includes a combination of different sensors that measure dynamic and static physical quantities, but also environmental parameters. HBM’s QuantumX data acquisition and analysis system, made up of MX840B universal amplifier modules and the CX22B-W data recorder, running HBM’s catman software, ensures high reliability, highly accurate sensing combined with an ease of use. Thus, the structural health monitoring system meets the requirements for extremely accurate and easily configurable data acquisition in this adverse environment.
The roadway test section was put in place to monitor the movements of three transverse cracks (F1, F2 and F3), separated by 7 meters and 5.9 metres respectively.
Structural health of Spanish roads suffers due to heavy vehicle traffic, material fatigue, and weather conditions. Problems such as breakages and cracks need to be fixed regularly.
By installing an automatic pavement monitoring station, the behaviour of the pavement, the bearing capacity, and weather influences can be measured. As part of the structural health monitoring system, HBM QuantumX data acquisition and analysis system combined with HBM's catman software allow for precise and flexible operation and fast configuration.
The system not only provides a sustainable and predictable maintenance system that gathes variables in real-time but also makes it possible to prevent or detect pavement damage and to react quickly when needed. In addition, enhanced materials can be developed by looking and analyzing the gathered data.
CEDEX aims to measure the bearing capacity of roadways and the material's reaction to various impacts.
The installed solution which includes sensors, the QuantumX structural health monitoring system and a weather station, is the only dynamic measuring and monitoring station in the sector. This structural health monitoring system set up by CEDEX in collaboration with HBM and engineering company Eo6 helps to establish predictive maintenance models and address specific problems. At the same time, the data obtained provide input for the development of new materials that serve as crack-deterring elements in the bituminous mix layers.
In its 1½ years of operation, the monitoring station has received some 600,000 signals, and has calculated the corresponding parameters and singular points of each one.
The pre-wrapped Carambars are placed in a hopper, which is used as buffer storage. They are taken by a cleated belt conveyor at a 45° angle, which pours them into plastic crates. Once full, the crates move along a conveyor system, before they are finally picked up by a collaborative robot, that places them on a pallet. “The specifications required a knowledge of the global weight of Carambars loaded onto each pallet. Rather than assessing the pallet, we have decided to weigh each crate individually and calculate the overall heaviness of the crates loaded onto the pallet,” explains Samuel Hacquin. “The load cell was placed under the crate, which had been filled by the cleat conveyor belt. This type of conveyor is obviously not suitable for dosing, as the sweets fall randomly by the dozen into the crate, so there is no precise control over their release. This does not matter though, as the crates don’t contain a specific number of sweets. What really matters is that we know the precise weight of each crate. The load cell needs to have a high level of accuracy and good repeatability - and obviously it must be sturdy because it is used a lot. The filling process for a crate takes a few seconds and - during this period of time - the cell weighs the empty crate before it’s filled. It carries out dynamic weighing to decide when to stop filling and then weighs the crate once it’s full.
Besides the various sensors that also record variables such as temperature and humidity, the monitoring station operates with HBM's QuantumX data acquisition and analysis system with MX840B and CX22B-W modules, as well as catman software. So, by using different technologies it meets the precision, flexibility, and speed of configuration requirements.
The QuantumX data acquisition and analysis system is capable of acquiring any signal and sensor information. Its universal and stand-alone MX480B and CX22B-W modules are especially suitable in applications with roadside load data, as they function with different types of sensors and have high computing power.
The catman software offers more than just data acquisition. It is perfectly adapted to roadside mobile test needs and provides ease of operation and data acquisition, online calculation, process automation and powerful display of any measured and recorded signal. In addition, HBM offers a stand-alone power solution, remote access, and online processing services.
HBM and CEDEX have been collaborating for a long time.
“Many years ago, we incorporated HBM equipment into our Pavement Accelerated Test Track at El Goloso, near Madrid, and since then we have only purchased their products, as they offer greater precision and allow work to be carried out with over 240 channels without interference,”
declared Javier Pérez Ayuso, the expert at the CEDEX Transport Study Centre.
The accuracy of the QuantumX measurement chain allows distinguishing between lorries and other vehicles crossing the structural health monitoring spot. Overloaded lorries can be detected and, if necessary, the relevant authorities can be notified and then proceed to identify them. The temperature and humidity measurements in the weather station are also very important for interpreting the data. The environmental data, for example, is essential for keeping roads clear in winter.
CEDEX and HBM are now working on an installation project for similar automatic monitoring stations on a section of the A-42 motorway in the province of Toledo.
The Public Works Studies and Experimentation Centre, more commonly known as CEDEX, is a body that applies cutting-edge ideas and technologies to civil engineering, construction, and the environment. It provides technological support from its facilities and laboratories through specific agreements.
CEDEX, which comes under the Ministry of Development, also has the job of disseminating knowledge and, in that regard, it performs a significant technology transfer task.
The Transport Studies Centre (CET), a part of CEDEX, with headquarters in El Goloso, Madrid, is devoted to specialized technical support tasks, technological research and development and innovation in the area of roads and transport in general.