Texas Tech University

Project 0-5873

Develop a New Testing and Evaluation Protocol to Assess Flexbase Performance Using Strength of Soil Binder


This research involved a detailed laboratory study of a new test method for evaluating road base materials based on the strength of the soil binder. In this test method, small test specimens (5.0in length and 0.75in square cross section) of binder material are load tested to obtain a flexural strength value. The laboratory study conducted in this research included material collected from 19 different sources. The results from the study demonstrated that good correlation can be established between the binder strength and 0-psi Texas Triaxial strength for certain types of base materials such as crushed limestone and materials treated with cement or flyash. However, the test method could not be used to measure the flexural strengths of many sand and gravel materials because these materials did not produce consistent data. The data obtained from repeatability analyses provided an average Coefficient of Variation (COV) of 12.6% for the base binder flexometer test and a COV of 23.2% for the 0-psi Texas Triaxial Test. The research effort also included the design and fabrication of a low cost, easy-to-operate prototype test device for the measurement of binder flexural strength. The reliability of the test equipment was verified by running parallel tests using another commercially available loading device.

new testing protocol