Strength performance of alkali activated structural lightweight geopolymer concrete exposed to acid

Abstract

This study investigates the performance of structural lightweight geopolymer concrete (SLWGC) exposed to chemical attack. The objective of this study is validation the ability of using light weight geopolymer concrete for structural purpose under hard conditions. The alkali activator was produced using sodium silicate, sodium hydroxide and water. Flay ash and slage as waste materials were replaced by 90% of ordinary Portland cement to produce the geopolymer concrete. Also, ordinary cement concrete produced to comparison. Three types of lightweight aggregate were used instead of normal aggregate represented by pumice stone, expanded clay and construction waste clay brick to produce SLWGC. The unit weight of produced SLWGC were in the range (1800–2100) kg/m3. Normal weight geopolymer concrete and SLWGC were produced simultaneously to compare their performance each with other. The geopolymer concrete mixes treated by heat curing at 65 °C for 24 h after removing the molds. The specimens of all mixes exposed to sulfuric acid with concentration 5% and 10% for 8 weeks. The investigated mechanical properties represented by compressive strength and flexural tensile strength. The results indicate that the geopolymer concrete exhibit better resistance for acid attack compared to OPC concrete where the strength deterioration for SLWGC lower than ORC light weight concrete after exposed to acid, crushed clay bricks exhibit superior mechanical and durability performance compared to other LWA. Finally, the results proved the ability of producing light weight geopolymer concert for structural purposed with acceptable performance of strength and durability under hard chemical conditions.