The Effect of Sodium Hydroxide Solution with Seawater on Compressive Strength of Geopolymer

Abstract

This research study the effect of sodium hydroxide solution with seawater to compressive strength of geopolymer. The ingredients are fly ash from Mae Moh Power Plant Lampang Province, sodium silicate solution (NS), Sodium hydroxide (NaOH) solution and seawater on the coast of Chonburi province. The test divided the test series as follows : 1.Series A: Change the solution to fly ash ratio (L/F), 2.Series B : Change the sodium silicate solution to sodium hydroxide solution ratio (NS/NaOH) and 3.Series C : Changes in the concentration of sodium hydroxide solution (NaOH). Test compressive strength of geopolymer at the age of 28 days. The test results Series A which changed the L/F from 0.5 to 0.7 showed that as the L/F increased the compressive strength was reduced. The highest compressive strength test results are in the L/F ratio = 0.50 using a solution of sodium hydroxide from seawater (NaSE) =100% Compressive strength of 463.89 kg/cm². This has a higher compressive strength than samples using a solution of sodium hydroxide from distilled water (NaDI)=100% slightly equal to 442.36 kg/cm². The test results Series B which changed the NS/NaOH ratio from 0.33 to 0.67 showed that as the NS/NaOH ratio increased compressive strength increased and as the NS/NaOH ratio increased from 0.67 to 1.50 compressive strength decreased. The highest compressive strength test results are in the NS/NaOH=0.67 which NaDI=100% (508.02 kg/cm²) higher compressive strength than NaSE=100% (506.40 kg/cm²) slightly. And the test results Series C which changed in the concentration of sodium hydroxide solution increasing from 5 to 10 molar compressive strength capacity was found to increase as the intensity increased from 5 to 10 molar but when the concentration was higher than 10 molar the compressive strength decreased.