Test Plan

CC2 Single Slab Test Plan

Three testing periods were experienced.

a)  During a three and a half month drying period, under the indoor natural environment condition, all sensors were monitored. At the end of that period, the measured average corner curling reached almost 200 mils (5.1 mm). Static load plate tests of up to 40,000 lbs (18160 kg), using increments of 5,000 lbs (2270 kg) or 10,000 lbs (4540 kg), were conducted at the end of this period to measure the displacements and strains of the seriously curled slab. 

 b)   The next period consisted of about a two month wet period achieved by routinely watering the slab surface. At the end of this period, the measured average corner curling was found to be stable and dropped down to 60 to 80 mils (1.5 to 2 mm). 

 c)   Then, at the beginning of December 5, 2003, similar static plate load tests up to 40,000 lbs (18160 kg) were conducted to investigate the slab response under a different curling degree. Different plate sizes with diameters of 18, 12 and 6 inches (45.7, 30.5 and 15.25 cm) were also used to find their effects on the critical strains and displacements. The plate load setup is presented in Figure 1 and the sensor locations are given in Figure 2.

 

 

Figure 1.  A single Load is applied at the single slab edge

 

The detailed pavement information, from structure to materials, is available. All load-time histories have been recorded during the tests. Therefore, the test results can be analyzed and further understood by comparing them with the results predicted by different models. In the past ten years, the FAA sponsored several projects for investigating the 3D model to be used for the new FAA airport pavement design specifications and analysis [1], [2] and [3]. The 3D model used in the above program was taken from a general purpose 3D finite element program Nike3D [5]. Numerical comparisons presented in this paper also include the results calculated by using the 3D program EverFe [6] and the 2D program Jslab2002 [4]. 

 


Figure 2.  Plane View of the Test Slab and the Sensor Locations (VD6 and 7 were added on December 5, 2003, and VD3 was disconnected on June 16, 2003)

 

References

1.      Brill, R. D, Field Verification of a 3D Finite Element Rigid Airport Pavement Model, DOT/FAA/AR-00/33, July 2000.

2.      FAA, Finite Element Design, Federal Aviation Administration, (FEDFAA), 2004

3.      FAA, 3D Finite Element Analysis of Rigid Airport Pavement, (FEAFAA), available HERE, 2004

4.      Guo, Edward H & May Dong, JSLAB-2002 Technical Report, under contract DTFH61-01-P-00255 with the Federal Highway Administration, 2002

4.      Guo, Edward H, Back-estimation of Slab Curling and Joint Stiffness, Proceedings of 7th International Conference on Concrete Pavements, September 9-13, 2001, Orlando, Florida. p39-44.

5.      Maker, B.M., Nike3D – An Nonlinear, Implicit, Three-Dimensional Finite Element Code for Solid and Structural Mechanics – User’s Manual Report, UCRL-MA-105268, Rev. 1, Livermore, California, Lawrence Livermore National Laboratory, 1995.

6.      Suprenant, Bruce A, and Discussion by R.E. Tobin, Why Slabs Curl? Part I and II, Concrete University of Washington and University of Maine & DOT of Washington State, EverFe V2 User’s Manual, 2003.