Mechanical Behavior and Durability of Perlite Based Mortar Exposed to Sodium Sulfate Attack

Abstract

The objective of this study is to gather additional on the impact of perlite on both the mechanical properties and resistance to chemical attacks of materials. Various combinations ,incorporating perlite in the form of cement additions, were examined. Five different substitution rates of 10 %, 15 %, 20 %, 25 %,and 30 % of cement with powder perlite were utilized for comparison with plain cement. The findings indicate that the interaction between lime,silica,and alumina in powder perlite results in the formation of several hydrates, such as calcium silicate hydrate, hydrated calcium aluminates,and hydrated gelhenite.Our research focuses on the development of natural perlite from maghnia as a potentially pozzolanic supplementary cementing material. In evaluating the pozzolanicity of this material, it was observed that external aggressions, such as chlorides, CO2, and chemical attacks, can compromise the physical and mechanical properties of concrete,affecting its long-term durability. However,natural pozzolans like pelite exhibit a positive influence on the durability of mortars against sulphate attacks. Test results revealed specimens with no apparent degradation, indicating that sulphate ions in the solution did not adversely affect perlite-based mortars. There is a growing preference for mineral additives with lower production costs than cement. Consequently, the optimal mixture was determined to be one containing 25 % perlite. However, cement pastes and mortars incorporating up to 20 % perlite demonstrated satisfactory physical and mechanical properties, comparable to materials without perlite. The investigation into the perlite materials used in conjunction with cement suggests the potential for sustainable concrete. Experimental results indicate that natural perlite powder from Maghnia can be considered a good pozzolanic material, suitable as a mineral admixture in cement production.

Keywords

• mortar
• cement
• perlite
• mechanical properties
• attack
• durability
• sodium sulfate
• chemical