Comparative analysis of environmental, social, and mechanical aspects of high-performance concrete with calcium oxide-activated slag reinforced with basalt, and recycled PET fibers

This paper studied the effects of steel, basalt, and recycled PET fibers on the environmental, social, and mechanical properties of high-performance concrete (HPC) with calcium oxide-activated slag (HPC-CAS). The energy consumption, greenhouse gas emissions, and human health impacts of concrete production were determined using resources, climate change, and human health indexes. The compressive strength, tensile and flexural strengths, modulus of elasticity, electrical resistance, and durability of HPC-CAS with different fiber types and contents were also measured and determined. Furthermore, the microstructure of HPC-CAS was examined by scanning electron microscope (SEM). The results revealed that 3 % recycled PET or basalt fibers increased the HPC-CAS tensile strength by 89 % and 55 %, respectively, and the flexural strength by 28 % % and 1.2 times, respectively, compared to specimens without fibers. The specimens with fibers also showed higher ductility and lower electrical resistance than those without fibers. The SEM analysis showed that basalt fibers had a better bond with the geopolymer matrix than recycled PET fibers. Basalt fibers had the lowest environmental impact and recycled PET fibers had the lowest social impact among the three types of fibers. However, recycled PET fibers also had lower mechanical performance and durability than basalt fibers. It was concluded, therefore, that the choice of fiber type for HPC-CAS depends on the balance between social, environmental, and technical criteria.