Experimental studies on strength and durability of alkali activated slag and coal bottom ash based geopolymer concrete

Abstract

This thesis work describes the experimental evaluation of the durability and strength properties of nominally mixed conventional concrete of grade M35, Alkali Activated Slag Based Geopolymer Concrete. Research on Rapid Chloride Permeability Test (RCPT) durability properties has been conducted. Sodium hydroxide (NaOH) and sodium Chloride (NaCl) must be mixed in a 2.5:1 M ratio and at molarities of 12 and 16, respectively, in order to make alkali activators, with dry curing and open-air curing serving as distinct curing regimes. NaOH concentrations of 12 M and 16 M were used to make nine distinct mixes, one of which was designated as the control mix. Then, these mixtures were cured at room temperature in the open air. Prior to the testing day, they were maintained at room temperature after a 24-hour dry curing procedure at 90 °C in a hot air oven. Each of the nine mixes underwent split tensile and flexural strength and durability testing after 90 days. Compressive strength tests are conducted at 28, 56, and 90 days. The results show that tensile strength increases as NaOH solution concentration decreases, but compressive and flexural strength increase as NaOH solution concentration increases. However, it was discovered that the Geopolymer concrete made from Alkali Activated Slag and Coal Bottom Ash (CBA) did not perform well in tests of water fast chloride penetrability because surface cracking predominated. When compared to the results of the control mix, the Alkali Activated Slag and Coal Bottom Ash (CBA)-based geopolymer concrete mix shows a superior improvement in strength measures than standard concrete. At this time, it seems that making geopolymer concrete costs less than regular concrete.