Analysis of the mechanical and environmental performance of concrete interlocking block pavement with by-products from the construction industry and waste from coconuts

Abstract

Urban road pavements made of concrete paving blocks (PB) and granular layers, such as base and sub-base, using industrial waste, are an improving sustainability goal for low to intermediate traffic areas due to the lack of helpful disposal of by-product generation. Then, this Dissertation aims to evaluate, by an innovative approach, the mechanical and environmental performance of concrete interlocking block pavement (CIBP) with by-products from the construction industry (construction and demolition waste – CDW) and waste from coconuts (coconut fibers – CF) for urban roads. Furthermore, a Life Cycle Cost Analysis (LCCA) was proposed for CIBP’s maintenance and reliability strategies. As this Dissertation was divided into four articles, a review paper was done first to compare CIBP skills with asphalt pavement (AP) for light-traffic urban roads. Regarding the second article, eighteen mixes for rectangular PB were used in Portugal with three water/cement ratios of 0.63, 0.73 and 0.83, CDW replacement rates of 50% and 75% by aggregate weight, and a CF adding percentage of 0.1% by concrete weight. Concerning the results, the CDW replacement of 75% by aggregate weight, CF adding of 0.1% and water/cement ratio of 0.73 were factors for providing PB for low-trafficked road pavements. About the third and fourth articles, a 175 m2–CIBP was built in Brazil with five experimental sections (S1, S2, S3, S4 and S5), four mixes for unistein PB with a CDW dust replacement rate of 50% by stone dust weight, and a CF dust adding percentage of 0.05% by concrete weight. Furthermore, eight granular mixtures made from non-plastic materials for base and sub-base layers were utilized with a CDW replacement rate of 100% and a CF adding percentage of 0.1% by mix weight. Regarding the third article, the air and surface temperatures from CIBP’s sections S1 to S5 were lower than the asphalt concrete from section S0. Furthermore, the CIBP construction stages showed average concentrations of particulate matter and carbon dioxide below the specifications. Concerning the fourth article, the CDW replacement of 50% by stone dust and CF adding of 0.05% were factors for concrete mixtures presented PB approved in specifications for water absorption and abrasion resistance tests. Also, the compressive and tensile strains from experimental CIBP in Brazil were lower than experimental AP in Portugal. About the LCCA on CIBP’s sections, S4 with CF and CDW materials showed costs lower than S2, S3 and S5 in 2045. These findings highlighted construction and coconut by-products for PB and sublayers as an alternative for the CIBP’s mechanical, environmental and economic feasibility.