Potential Application of Using Multi-Head Pavement Breaker for Concrete Pavement Rubblization over Weak Subgrade

Rubblization is a process of mechanically breaking the existing concrete pavement into smaller-sized pieces using heavy-duty pavement breakers, such as Resonant Pavement Breaker (RPB) and Multiple-Head Breaker (MHB). Previous research studies indicated that bothpieces of equipment could perform well when a strong subgrade is present under the concrete layer. However, when the subgrade is relatively weak, subgrade yielding could happen during the rubblization. The use of MHB in rubblization has increased significantly over the past few years because MHB can adjust the amount of fracturing energy transferred to the pavement, which can help control the subgrade damage potential. In this study, a numerical damage model based on impact loading and fracture energy will be proposed to predict the behavior of the weak subgrade under MHB drop hammers. This model can potentially be used to calibrate the rubblization operation (speed, frequency, weight, height of hammer drop, etc.) of MHB for rubblizing concrete pavements over weak subgrades.