Improving the Properties of Recycled Aggregate Concrete Pavement Brick by Addition of Waste Nylon Filament

A lot of waste nylon filament (WNF) is produced during the production of brush filament products. The reuse of WNF has attracted the attention of many researchers. The objective of this research is to investigate the feasibility of WNF as reinforcing material in concrete pavement bricks. WNF, cement, recycled aggregate (RA), sand and water were used to produce waste nylon filament concrete pavement bricks (WNFCPB). The effects of cement content, water to cement ratio (w/c), WNF to cement ratio (wnf/c), recycled aggregate (RA) content on the physical and mechanical properties of WNFCPB were evaluated. The mix proportion was determined by means of orthogonal test. The results indicate that WNF has an excellent tensile property and plays an important role in the improvement of properties of WNFCPB. Taken into account the results of the flexural test and water absorption test, the optimum mix proportion is as follows: cement content is 400 kg/m3, water to cement ratio(w/c) 0.40, WNF to cement ratio (wnf/c) 1.00%, RA content 1030 kg/m3. The brick is suitable for paving sidewalks due to its excellent performance in bending resistance and water absorption. The reinforcing mechanisms were discussed using the binding effect, the thin shell effect and fiber-reinforced composite strength theory.