Evaluation of Blow-up Susceptibility Based on Base Type in Jointed Concrete Pavements

Abstract

Blow-up in jointed concrete pavements is a critical failure of concrete pavements caused by the accumulation of excessive compressive stress, primarily induced by thermal expansion. Since this phenomenon occurs suddenly and may accompany large-scale upward heaving of concrete slabs, it poses severe safety risks to road users. Historical records show that blow-up occurrences have been significantly more frequent on highways in the United States than in South Korea or the United Kingdom. In South Korea and the United Kingdom, concrete slabs are typically constructed on a lean concrete base covered with polyethylene sheet (LCB-PE), whereas in the United States, a wider range of treated and unbound bases have been employed. Geometric imperfections and base friction, the two primary factors influencing blow-up occurrences, vary significantly depending on base type. Therefore, the more frequent observation of blow-up in US highways may be attributed to differences in base types of concrete pavement. This study investigates the influence of base type on blow-up susceptibility using the pavement growth and blow-up analysis (PGBA) model. The model mechanistically evaluates the blow-up threshold stress and the annual maximum compressive stress in jointed concrete pavements under conditions of climate, pavement structure, material properties, and expansion joint configurations. To this end, blow-up initiation times were evaluated under various conditions of maximum annual air temperature, coefficient of thermal expansion, slab thickness, expansion joint spacing, and alkali–silica reaction in jointed concrete pavements constructed with the two representative base types: an LCB-PE; and a granular base. The PGBA results indicated that, under identical conditions, blow-up occurred substantially earlier in jointed concrete pavements with granular bases than in those constructed on LCB-PE. This difference is attributed to greater geometric imperfections and slab–base friction observed in pavements with granular bases.