Remediation of Alligator Cracks in Asphalt Concrete Pavements: A Case Study of Port-Harcourt-Aba Expressway in Port Harcourt, Nigeria

Chinonyerem B. Onyekaba

Department of Civil Engineering, Rivers State University, Nkpolu Oroworukwo, Port Harcourt, Rivers State, Nigeria. 

Abstract

Alligator cracking is a critical fatigue distress in asphalt pavements, appearing as interconnected crack patterns that indicate structural failure under repeated heavy loading. This study provides a comprehensive review and field-based assessment of alligator cracking on the Port Harcourt-Aba Expressway in Nigeria’s Niger Delta. The region faces intense heavy vehicle traffic from oil and gas operations, high rainfall, weak moisture-sensitive subgrades, and inadequate drainage. Drawing on recent literature (2021–2025) and 2025 field data, overloading, subgrade instability, and poor drainage emerge as primary causes. Severity-based remediation strategies are evaluated, with milling followed by thick hot-mix asphalt overlays proving highly effective (approximately 60% reduction in crack density in trial sections). Emerging technologies, such as nanomaterial-enhanced sealants for self-healing and machine learning for predictive maintenance, are recommended to enhance long-term durability. These findings offer practical guidance for sustainable pavement management in tropical, high-traffic environments.

Keywords: Alligator cracking; Fatigue distress; Pavement remediation; Port Harcourt-Aba Expressway

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