{'fraction_non_alphanumeric': 0.014723203769140165, 'fraction_numerical': 0.0035335689045936395, 'mean_word_length': 5.509578544061303, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Design of Rehabilitation Treatments for New Zealand’s Thin-Surfaced Unbound Granular Pavements

Most thin-surfaced unbound granular pavements are rehabilitated by overlaying with an unbound granular material and surfaced with a chip seal (thin-surfacing). The unbound granular overlay thickness is the difference between the total granular thickness required for future traffic and the granular thickness required for past traffic as determined from the design chart. However, where there are signs of shoving or other indications of a weak and degraded aggregate base layer then a smoothing treatment will not be adequate. For this situation the appropriate rehabilitation is either in situ stabilization (to improve the strength of the aggregate base material) or to cover with a minimum thickness of unbound granular material (determined from the thickness design chart by assuming the existing pavement acts as a subbase). This method of unbound granular overlay design has resulted in significant cost savings over the past 20 years in rehabilitation treatments for New Zealand roads, as the existing pavement has been fully utilized. In 1995 New Zealand adopted the Austroads (the Association of State, Territory and Federal Road and Traffic Authorities in Australia) procedures for pavement design. The Austroads procedures encourage the use of mechanistic procedures for pavement design. By using the same assumptions as the design chart method for determination of granular overlay depths, a mechanistic design procedure for rehabilitation treatments was developed. This method produces comparable results and has the advantage of being able to design a range of rehabilitation treatments.