Experimental Investigation of the Effect of Natural Zeolite Pozzolan on the Mechanical Properties and Water Absorption of Ordinary Portland Concrete

Pirmohammadi Alishah, Farhad; Mohammadrezaie, Mehdi

doi:10.22034/cpj.2026.593350.1463

Experimental Investigation of the Effect of Natural Zeolite Pozzolan on the Mechanical Properties and Water Absorption of Ordinary Portland Concrete

10.22034/cpj.2026.593350.1463

Articles in Press, Accepted Manuscript
Available Online from 25 July 2026

Document Type : Research Article

Authors

farhad pirmohammadi alishah ¹

Mehdi Mohammadrezaie ²

¹ Faculty Member and Assistant Professor, Department of Civil Engineering, Faculty of Engineering and Engineering, Islamic Azad University, Shabestar Branch, Shabestar, Iran

² Department of Civil Engineering, Shab.C., Islamic Azad University, Shabestar, Iran

Abstract

This study investigates the influence of natural zeolite as a supplementary cementitious material (SCM) on the mechanical properties and water absorption of ordinary Portland concrete. Zeolite was used as a partial cement replacement at levels of 0%, 2%, 6%, 8%, 12%, and 15% within various mix designs (cement content ranging from 320 to 400 kg/m³). The experimental program focused on evaluating compressive strength at 7 and 28 days, as well as water absorption capacity. The results indicate that while early-age (7-day) compressive strength experienced a slight decrease due to the dilution effect of the zeolite, 28-day strength significantly improved at an 8% replacement level. Furthermore, water absorption tests reveal that the pozzolanic reaction of zeolite refines the interfacial transition zone (ITZ) and reduces capillary porosity. The findings suggest that natural zeolite, when properly proportioned, enhances the long-term durability and structural efficiency of concrete.

Keywords

Natural Zeolite

Ordinary Portland Concrete

Compressive Strength

Water Absorption

Pozzolanic Reaction

Subjects