DefinePK

Abstract

The present study focused on the production of alkali activated flyash lightweight aggregate by means of pelletization. The basic physical properties and mechanical characteristics of lightweight aggregate produced were analyzed systematically. Factors affecting the efficiency of pelletization process such as type of binder, moisture content, process duration and alkali content were evaluated. Further, characterization of aggregates was evaluated based on the specific gravity, gradation, density and aggregate crushing strength. It was observed from the test results that the pelletization efficiency of different aggregates was found to be maximum when the angle of pelletizer is set to 36º with an optimized speed of 55 rpm. Also, compared to other types of pelletized flyash aggregates, the aggregates containing flyash mixed with 20% cement and 12M NaOH exhibited a higher crushing strength of 13.72 MPa with minimum water absorption of 18.33%. With the optimum addition of water upto 31% during pelletization, the efficiency and strength of aggregates were found to be increased. In addition, the optimum pelletization duration (15 to 20 minutes) resulted in higher compaction energy with uniform size of aggregates. Also, the addition of alkali (NaOH) to flyash aggregates showed higher strength gain within shorter curing period in hot air oven.