Research and application of a black rapid repair concrete for municipal pavement rehabilitation around manholes

Abstract Cracks and potholes around manholes on carriageways have long been a problem for municipal asphalt concrete roads. The traditional repairing method not only requires a long period of traffic interruption, but also does not meet the requirements of durability and aesthetic appearance. A black rapid repair fibre concrete (BRRFC) was developed for asphalt concrete pavement rehabilitation around manholes, based on a series of optimisation and scaled tests. As a super high-early-strength concrete, BRRFC has capacity to carry normal traffic loads after pavement manholes repairs for 8 h. Meanwhile, it offers other advantages such as uniform and stable black colour, good performance in dry-shrinkage and wear resistance, low-cost, and easy construction. Applications of BRRFC in numerous municipal maintenance works showed that rehabilitated manhole areas were still intact and no obvious colour difference between the new and old pavement concrete after several years of service, achieving significant social and economic benefits for sustainability.