Characterization of Substandard Limestone Aggregates Using XRF, XRD, and SEM: Implications for Cement Paste Reinforcement in Concrete Applications Edward Ngii, La Hamimu, Abdul Kadir, La Ode Hasan Jamilu, Adi Kumala, Slamet Slamet Media Konstruksi : Jurnal Ilmiah Teknik Sipil Vol. 9 No. 4 2024 DOI 10.33772/medkons.v9i4.79