Utilization of Labuhan Batu red sand post heavy metals adsorption as sources of high-quality concrete material

Red Sand (RS) is used as an absorbent for heavy metals, then the red sand absorbed by heavy metals is used as a basic material for making concrete. Red sand adsorbed of heavy metals Mn(II), Pb(II), and Zn(II) were 0.39 mg/g, 026 mg/g. and 0.27 mg/g, respectively. From the results of these optimum conditions, then used for making concrete, they were tested for compressive strength. The highest compressive strength of the 4 experimental samples was obtained by a mixture of fine aggregates of red sand after adsorption of the heavy metal Mn(II). The results of successive concrete compressive strength tests using a mixture of red sand fine aggregate after adsorption of heavy metals Mn(II), Pb(II), and Zn(II) were 7.85 MPa, 6.58 MPa, and 5.85 MPa. This result was higher than red sand without heavy metal at 5.69 MPa. Concrete using a fine aggregate mixture of red sand after adsorption of the heavy metal has a compressive strength test that is higher than concrete from red sand without adsorption of heavy metals. XRD pattern and SEM image show the property change of RS. It became a new strategy to produce high-quality concrete and also resolve heavy metal contamination in the environment.