Investigation of Maintenance Base Repairs over Expansive Soils: Year 1 Report (0-4395-1)

Some of the most prevalent cases of distress pavement maintenance forces will encounter in expansive soil environments are roughness, longitudinal cracking, and structural deterioration. This report describes the findings from an extensive literature search, a multi-district survey, numerous field site investigations, and a laboratory testing sequence, all geared toward identifying what types of maintenance treatments and materials give good performance when used on the above distresses. For moderate cases of roughness, a blade-on patch to smooth the section is quick and is the most typically used treatment. Data collected indicate crack filling and sealing is just as effective as conventional full-depth patching for longitudinal cracking. For full-depth repairs due to longitudinal cracking, methods currently being used in the Bryan District of the Texas Department of Transportation (TxDOT) using geogrid reinforcement to prevent cracks from propagating through the pavement surface show promise. In general, all data collected indicate cement treatment is preferred to asphalt cold mixes for base repairs.TxDOT should consider constructing test sections utilizing the field guide developed as part of this project to verify its usefulness. TxDOT should also consider test sections reworking areas with longitudinal cracking utilizing different geosynthetics to determine if similar performance can be obtained with less costly geotextiles and grids.