Investigating the mechanical properties of activated alkali high permeability concrete according to the ratio of alkaline activators Amir Zohrabi 1 , Rasoul Alipour 2 , Alireza Jahangiri 3 1.Department of Civil Engineering, Shahrekord University, Shahrekord, Iran. E-mail: amir73zohrabi@gmail.com. 2.Corresponding Author, Department of Civil Engineering, Shahrekord University, Shahrekord, Iran. E-mail: r.alipour@sku.ac.ir. 3. Department of Civil Engineering, Shahrekord University, Shahrekord, Iran. E-mail: jahangiri@sku.ac.ir. Article Info ABSTRACT Article type: Research Article Article history: Received 2024-03-11 Received in revised form 2024-04-22 Accepted 2024-06-06 Available online 2024-06-25 Keywords: active alkali, Porous concrete, PSO, slag, sodium hydroxide, sodium silicate This research investigates the mechanical properties of alkali-activated porous concrete compared to cement-based porous concrete. In this regard, the slag of blast furnaces has been used as the base material for cement, and sodium hydroxide and sodium silicate have been used as alkalizing materials. Alkali-activated porous concrete was made with 8 Molar sodium hydroxide solution with ratios of sodium hydroxide to sodium silicate 1:2, 1:1, and 2:1. To check the mechanical properties, compressive strength and tensile strength tests (Brazilian test) were tested at the ages of 90, 28, 7, and 120 days according to the proposed standards. Compared to sample concrete, the compressive strength and tensile strength of porous concrete with active alkali in the ratio of 1 to 2 have been reduced by 75 and 69 percent. The same comparison shows a decrease of 51 and 41% in the ratio of 1:1, and in the ratio of 2:1 sodium hydroxide to sodium silicate, the compressive strength increases by 28% and the tensile strength by 12% compared to porous cement-based concrete at the age of 120 days. Cite this article: Zohrabi, Amir., Alipour, Rasoul., & Jahangiri, Alireza. (2024). Investigating the mechanical properties of activated alkali high permeability concrete according to the ratio of alkaline activators. Advanced Modeling in Civil Engineering, 1(1), 65-80. DOI: 10.22126/amcen.2024.3287 © The Author(s). Publisher: Razi University DOI: 10.22126/amcen.2024.3287