THE REVISION OF THE CONCRETE PAVEMENT THICKNESS DESIGN PROCEDURE OF CHINA

Abstract

In the pursuit of advancing concrete pavement design practices in China, this paper discusses a significant revision of the thickness design procedure for concrete pavements. Initiated due to the extensive application and subsequent research findings from nearly 10,000 kilometers of concrete roads built since 1984, this revision aims to incorporate accumulated design experiences and research insights. The original design specification, focusing on preventing fatigue cracking by limiting stress induced by design axle loads, is expanded to address combined fatigue damage from both traffic loads and temperature gradients. This includes the introduction of a new fatigue equation derived from flexural fatigue tests, the consideration of stress reduction factors based on load transfer efficiency at joints, and the integration of inner stress and thermal curling stress effects due to temperature gradients. The revised methodology acknowledges the crucial impact of fluctuating temperature gradients alongside traffic loads on pavement durability. It employs a comprehensive approach by considering various factors such as the cumulative fatigue damage, the efficiency of load transfer across joints, and the non-linear distribution of temperature within the slab. The adoption of a fatigue thermal stress factor enables the quantification of cumulative effects from daily and annual temperature fluctuations. This abstract presents a succinct overview of the methodology's enhancements, demonstrating a holistic approach to concrete pavement thickness design. It underscores the integration of empirical data and practical observations into a refined model that aims to enhance the longevity and performance of concrete pavements under complex operational and environmental conditions. (Abstract generated by AI tool ChatGPT 4)