Ingenieurbüro Jäger
Civil Engineering
Bearing monitoring

Sensor for compressive stresses in concrete

With the sensor BBS 10_DS from IBJ Technology, surface pressure in concrete components can be determined also afterwards. The applications range from the direct stress measurement in the component to the measurement and monitoring of dynamic loads in real time.

With ultrasound, the stress is captured in the building directly and in real time. All changes can be transferred online via the Internet or satellite radio of the elite. The sensors are either placed directly in the building, or subsequently attached to exposed to. Construction elements such as vehicles or bridges bearing may be easily monitored. The sensors are constantly active on or in the building. The simple design and small size allow the full application of all structures made of steel or concrete. All civil engineering works are static loads and stresses and small dynamic changes.
After the procedure, many important civil engineering works could be monitored worldwide. The costs of such controls are minimal.
The collapse of buildings goes hand in hand with a measurable change of stresses and loads. These are correlated with the stove data of seismic events worldwide available and checked for plausibility. This surveillance of buildings of all kinds on damage caused by disasters (soil landslides, earthquake, mudslide, etc.) also is possible.

Retrofitting the sensors in holes 1 inch are built into the concrete parts. With swelling mortar we a force-fit composite with concrete part achieved.

A low overall height of the sensors was elected to allow installation in boreholes for many different applications. The installation of the sensors is diameter holes approximately 1 inch.
Each sensor is clearly identifiable with the encoding of sensor in ROM.

Approx. up to 50.000 measurements per second can be made with a suitable control and evaluation unit.

The monitoring of all possible curtails and structural parameters during the construction and operation of buildings is the basis for the State and safety analysis of the building. On-line measuring method with the sensors from IBJ Technology force and load measurement, especially stress in concrete, are not to replace their validity and relevance.

Further applications arise as transducers for dynamic load changes.

The usability of buildings can be so online monitor.
According to seismic effects, changes in the load capacity of foundations are recognized immediately.

Sensor for tensile and compressive stresses in the concrete to measure

After the patent-pending process of IBJ Technology sensors for strain and compressive stresses can be manufactured in almost all imaginable sizes. The area includes a 1 inches to several 10 foot length. The diameter of the measuring element can be adjusted to the diameter of the reinforcement in the concrete.
The sensor detects the strain or deformation of a metal rod. This metal rod can be arranged in the iron braid of reinforcement.
Elongation are measured with ultrasonic pulse-echo method. In the connecting head of the concrete stress sensor, an ultrasonic sensor is included. The runtime in the measuring element is measured in high resolution.
The run-time increases linearly with the stretch in the elastic range.
The concrete surrounding the tension sensor the measuring element under load imposes a strain, or extension. The change in the length of the measuring element is not only load or stress-dependent, but also on the temperature. Therefore, a permanent temperature measurement is integrated into the tensile stress sensor.
The monitor to measure the elongation takes into account both factors.
The term due to the change in length and akousto elastical effect has grown due to the action of the surrounding concrete to the measuring element.
The monitor is equipped with a microprocessor determines the respective difference to the reference measurement without load or stress and calculates the length change in stress to.
The absolute resolution of the sensors is regardless of its length and better than 0.00001 inch.
An important application is the use of sensors to measure the steel strain of reinforcement. The cross sections and the diameter of the measuring elements equal to or less than selects the reinforcement, exceeding the maximum yield strength of reinforcement elements can be avoided.

The monitoring of the structure on load deformation can be integrated in a monitoring system for building monitoring thus. It listens on exceeding the critical strain of steel reinforcement.

With the new strain sensors from IBJ Technology can critical operating States under previously incorrectly estimated or calculated
Combinations led to an undersized reinforcement, in good time, before the failure of the building, are recognized.

Buildings with highly varying load factors can be monitored efficiently online.

Acoustoelastical concrete strain gauge


Acousto elastical concrete strain transducers are for metrological detection
Strain or deformation of steel building components as well as reinforced and non-reinforced
Concrete pieces used. The strength of the transducer (diameter of the rods) can be selected according to the strength of the reinforcement.

The acousto elasical concrete strain gauge can be mounted outside on construction parts made of steel. With flanges or angle mounted easily. The variable length of the sensors is especially beneficial. The reduction of the sensors can be done on site. The terminal points of the sensors are freely selectable within the length of the sensor.
By default, the Terminal spacing between 1 inch and 10 foot are to choose. Longer sensors are possible on request.

Acousto elastical concrete strain sensor subject to no aging.
Due to the principle of running time measurement in a steel rod, long term drift and change the calibration data are irrelevant.

Temperature-related changes in length captured by means of a built-in temperature sensor.

Technical data

Measuring length 1 inch to 1000 inch (extra length on request)
Rod diameters from 0.4 to 1.3 inch (other diameters on request)
Measuring range 3000 mµ (nominal)
Resolution stretch 0,1 mµ (at 1m)
Resolution run 1 ns
Resolution stretch absolutely 0.00001 inch
Operating temperature-20 ° C to + 60 ° C


The recording and evaluation of measured data by means of a bolt stress monitor

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