<p>The reinforced concrete pipes are commonly used in sewer systems for ensuring efficient wastewater management, assist in maintaining safe and hygienic environment for surrounding inhabitants. However, conventional cement concrete pipes may lead to cracking under heavier loads, coupled with biogenic acid attacks leading to compromise the structural integrity of the entire sewer system. Therefore, this study explores fly-ash-based cementless concrete incorporating plain, bundled, and wavy fibers made from recycled steel wires at dosages of 25, 50, and 75 kg/m³ for manufacturing spun-cast precast pipes, with the aim of enhancing both structural performance and durability. Micro-polypropylene (PP) fibers at dosages of 5, 10, and 25 kg/m³ were also investigated. Material characterization of fiber-reinforced cementless concrete was performed via compressive, splitting tensile, and flexural strength tests, along with water absorption tests. A selected fiber-reinforced cementless concrete mixture was used to cast full-scale precast pipes via the spun-cast technique. Improvements in mechanical properties were observed on account of steel fiber addition. For instance, the flexural strength was enhanced by about 35% at 56 days for the mixture having 50 kg/m³ of wavy steel fibers, compared to the control fibreless mixture. Fiber addition also decreased the water absorption. Mixtures incorporating wavy steel fibers outperformed identical mixtures made with bundled and plain steel fibers. However, micro-PP fibers had an adverse effect on water absorption and compressive strength due to poor consolidation and increased void volume. It can be argued that the cementless concrete mixture incorporating 50 kg/m³ of wavy steel exhibited 28-days compressive strength comparable with the ASTM C76 requirement (i.e., 27.6 MPa) and local practice of slump value of 10 mm for pipe casting using spun-cast methodology. Pilot testing was performed on full-scale precast cementless concrete pipes incorporating wavy fibers. Flexural cracks at the pipe spring-line, invert, and crown were observed upon the three-edge bearing load. The sustainable precast pipes incorporating wavy fibers achieved superior cracking and ultimate load capacity owing to fiber crack bridging. The findings highlight the potential/significance of fiber-reinforced fly-ash-based cementless concrete mixtures in the full-scale manufacturing of precast pipes using the spun-cast technique. This offers a novel, viable and eco-friendly option for developing sustainable civil infrastructure with a reduced carbon footprint at economical costs.</p>