Parking lots, pathways, and approaches can all be Paved with concrete paver blocks. When traditional construction methods are proven to be undesirable, Interlocking Concrete Block Pavements (ICBP) are utilized to provide pavements in those areas. Fly ash is produced daily in significant quantities as a byproduct of the Norochcholai Coal Power Station in Sri Lanka and is regarded as hazardous to the environment. Based on results obtained from compressive strength, water absorption, and scanning electron microscopy analysis, this research focuses on using this fly ash to improve the ICBP aggregate packing model. The experiment results indicated that Fly Ash could replace 23 and 21 percentages of the cement in Grades 15 and 20 respectively in OPC mixtures and 26 and 21 percentages of the cement in Grades 15 and 20 respectively in PLC mixtures. Reduced cement content requirement and heat of hydration, improved durability, and makes this economically viable.