Concrete Coefficient of Thermal Expansion
InstroTek®, Inc. has developed an advanced method and device for measuring the Coefficient of Thermal Expansion (CTE) of concrete. CTE measurements play a very important role in behavior of concrete pavements. Accurate CTE values are necessary for performance prediction models in the Mechanistic-Empirical Pavement Design Guide (MEPDG). High CTE values correspond to greater predicted amounts of slab cracking, greater joint faulting, and greater pavement roughness.
By controlling the saturation level of the concrete specimen and varying the temperature, the AutoScan_CTE can quickly and accurately determine the CTE of concrete samples. It is capable of testing 4 inch or 6 inch (100 mm and 150 mm) diameter samples and is designed to accumulate all height measurements without surface treatments, special holding jigs or other accessories. All height measurements are accomplished using a high precision LVDT and an innovative displacement measurement method to ensure that the LVDT is kept at room temperature and not exposed to temperature changes during the testing routine.
The System is fully automatic with microprocessor control of temperature and all other critical functions. The CTE values are calculated and displayed on a user friendly GUI (Graphical User Interface) when the test cycle is complete.
Now Engineers and researchers alike have a cost effective tool for improving the performance of concrete pavements.
- AutoScan_CTE meets the requirements of AASHTO T336-11.
- The LVDT used in the AutoScan_CTE is located outside the water tank contacting only the surface of the concrete sample. This allows the LVDT to stay at ambient room temperature increasing its life expectancy and overall system reliability.
- AutoScan_CTE uses a solid state, environmentally friendly temperature conditioning system and does not require a separate heating/chilling unit.
- The unit is ergonomically designed and fully integrated for laboratory bench top operation.
- All measurements, calculations and data storage functions are automatic and controlled with a PC.
- The AutoScan_CTE is easy to use with minimal operator involvement.