Potential application of by-products from the construction industry and waste from coconuts for concrete road paving blocks: physical and mechanical properties

This paper analyzes concrete paving blocks (CPB) with mixed recycled aggregates from construction and demolition waste (CDW) as by-products and coconut fibres (CF) as waste, a novelty of these types of blocks, through physical and mechanical characterisation. Then, eighteen mixtures were used to produce rectangular CPB 20 cm x 10 cm x 8 cm (length x width x thickness): three without CDW and CF (with natural aggregate), six with CDW materials (3 replacing natural aggregate by weight in 50%, and other 3 in 75%), three with CF (adding a percentage of 0.1% by concrete weight), and six with CDW materials and CF. Tests, such as visual inspection, water absorption, voids, and compressive strength at 7 and 28 days, were done for blocks CPB with three water/cement ratios of 0.63, 0.73, and 0.83. The results showed that the mixes with different uses of CDW and CF behave better than the equivalent reference mixtures. Then, the study supports the CPB with CDW materials and CF can be used on light motorised trafficked road pavements.