Mechanical and Microstructure Properties of Porous Geopolymer Concrete Based on Umeanyar Slate Stone Powder

Abstract

The growth of city areas has led to a reduction in places where rainwater and other water sources can be collected, largely due to the expanding surfaces covered in concrete. One potential answer to this issue is the use of permeable concrete. To minimize the amount of cement used in permeable concrete, this study explores the application of geopolymer materials in creating porous geopolymer concrete. The geopolymer binder utilized consists of slate stone powder waste sourced from Umeanyar Bali, along with an alkali activator (NaOH and Na₂SiO₃). Various proportions of geopolymer binder were tested to assess the mechanical features and microstructure of the porous geopolymer concrete. All samples were evaluated at the ages of 7 days and 28 days. The mechanical properties assessed include tests for compressive strength, splitting tensile strength, porosity, and permeability according to ACI 522 R10. Simultaneously, the microstructure analysis used X-ray Diffraction (XRD). The peak results for compressive strength reached 13.67 MPa, splitting tensile strength was  1.87 MPa, porosity measured at 18.67%, and permeability was recorded at 8.58 mm/s. These mechanical testing outcomes fulfill the standards outlined in the regulations and can serve as an environmentally friendly construction material.