Experimental evaluation of the pullout resistance of metalic and polymeric strips within construction and demolition wastes
Reinforced earth; Pull-out test; Construction and demolition wastes; Mechanically Stabilized Earth Walls
Civil construction serves as a cornerstone for economic and societal progress within nations. However, its undeniable significance is accompanied by a concerning ecological footprint. Recent studies have indicated that the construction sector accounts for nearly half of global natural resource consumption and is responsible for a quarter of waste generation and CO2 emissions. This predicament underscores a pressing environmental challenge. In response, the recycling and repurposing of Construction and Demolition Waste (CDW) within the construction industry presents a potent avenue to safeguard natural resources, mitigate environmental impacts, and foster sustainable development. In this context, this study aims to assess the viability of employing CDW as structural fill material in mechanically stabilized earth walls through full-scale pull-out tests. To gauge its efficacy, the findings are juxtaposed against the geomechanical behavior of conventional natural sand, widely utilized in reinforced soil solutions. Furthermore, design parameters derived from laboratory tests, accounting for diverse design conditions, are compared against values established by standard technical protocols and design guidelines. Furthermore, a meticulous analysis of chemical and electrochemical attributes is conducted to evaluate durability and resistance to corrosion and degradation of reinforcement elements. Despite not fully conforming to the grain size distribution criteria stipulated by several international regulations – which advocate for the use of well-graded soils – the recycled CDW demonstrates commendable performance and remarkable mechanical characteristics, particularly regarding the resistance to pullout of metallic reinforcements with bumps and conventional synthetics. This performance level is on par with or surpasses that of natural sand, exhibiting comparable or superior pull-out resistance parameters. Consequently, the application of recycled CDW as an environmentally friendly alternative for total or partial replacement of conventional natural aggregates emerges as a promising solution. The viability of this approach is contingent upon satisfying additional design prerequisites. It is noteworthy that the recycled CDW gravel exhibits elevated concentrations of chloride and sulfate ions, alongside diminished electrical resistivity values. Complementing these findings, an analytical model is formulated based on pull-out tests, capable of predicting the response of metallic ribbed strips in alternative geotechnical materials, predicated upon their grain size distribution. This model adds a valuable predictive dimension to the utilization of sustainable materials in geotechnical engineering applications.