Mechanical Characterization of Gypsum-Based Composites with Single-Use Sling Waste Fibers from Construction and Demolition Waste

Construction and demolition waste (CDW) produced in a construction work site generates problems in its management. Among the CDW, we can find polymers, which create an added problem because of their slow decomposition, nonreuse, and whose manufacture generates greenhouse gases, which are harmful to the environment. Therefore, to reduce and recycle CDW as an alternative raw material to manufacture construction materials and elements and minimize the waste sent to landfill is urgently needed. This article analyzes the incorporation of CDW polypropylene fibers from single-use slings into gypsum and plaster composites. Additionally, commercial polypropylene fibers were also incorporated to compare the results. For this, several specimens were prepared adding different weight percentages of CDW fibers from 1% to 4% and tested to determine their physical and mechanical properties: bulk density; superficial hardness; flexural and compression strength; and bonding strength. Results show that it is viable to use CDW polypropylene fibers to manufacture new gypsum-based composites, as all the results surpass the minimum values determined by the applicable standards. Better results were obtained when CDW polypropylene fibers were used instead of commercial ones. The increase of flexural strength is more representative than other mechanical properties. The inclusion of CDW fibers in composites allows the reduction of slings thrown into landfills, which reduces the generation of greenhouse gases to the environment in the manufacture of new fibers for mortar reinforcement.