Resistance of Geopolymer Mortar to Sulphates Attack (Using Local Pozzolana in Southern Libya)

Abstract

Sulfate attack is one of the causes that lead to deterioration and damage of concrete structures
worldwide. Therefore, resistance to sulfate attack is an important concern for the durability and
quality of construction materials. Various samples of geopolymer cement and ordinary Portland
cement (OPC) were manufactured to evaluate their resistance to sodium sulfate attack. This paper
studied the extent of resistance achieved by geopolymer mortar using locally sourced pozzolana
from the Sabha region against sodium sulfate attack and compared it with ordinary Portland
cement. The specimens were immersed in a 10% sodium sulfate solution for a duration of up to
120 days. The evaluation was based on measuring the effect of the sulfate solution on the
compressive strength of the geopolymer mortar cubes and comparing them with ordinary cement
mortar. The results indicated that the geopolymer cement samples exhibited higher resistance to
sulfates compared to ordinary cement samples under the same conditions and concentration.
Overall, the geopolymer cement materials performed better in the sodium sulfate solution
compared to ordinary Portland cement (OPC).