One of the main objectives of SHRP has been the development of more reliable testing methods for assessing the field performance of asphalt pavements. The methods and equipment developed by SHRP indirectly evalute field performance and mechanical properties by the laboratory testing of samples. A concentrated research effort was directed to extending the SHRP methodology by developing a portable, in-situ shear strength test device. This device was designed and fabricated at Carleton University, and is known as the Carleton In-Situ Shear Strength Test device (CISSST).

This paper presents a description of the development and details of the device, its use in the field and the results of a variety of field situations. The results show the profound effect of road geometry (in-situ shear strength of up to 60% higher on a straight line as compared to curved sections), the effect of taking cores to the laboratory for testing (in-situ shear strengths can range up to 300% higher), and the effect of traffic on the in-situ shear strength.