STRENGTH, SUSTAINABILITY AND CONSTRUCTION SUITABILITY OF LIGHTWEIGHT CONCRETE BLOCKS MODIFIED WITH AIR-ENTRAINING AGENT AND CERAMIC POWDER

Abstract

This study investigates the use of air -entraining agent (AE192), fly ash and ceramic powder in lightweight concrete blocks as sustainable alternatives to locally available first-class bricks. A 1:2:4 cement: sand: coarse aggregate mix was prepared with 20% fly ash replacement and ceramic powder as fine material replacement with AE192 dosages of 5%, 8%, and 10%. Specimens were tested for strength, weight loss and suitability for construction at 7, 14 and 28 days. The control mix attained the maximum compressive strength while the 5% AE192 mix showed the best balance by retaining approximately 90.7% of the control strength in Sample 1 at a reduced weight and achieving around 19.0% weight reduction in Sample 2. Higher AE192 dosages showed higher strength loss but better lightweight performance, thus being more suitable for non-load-bearing and insulation applications. The sustainability potential of the ceramic-powder modified blocks was improved and the 10% ceramic/AE192 mix performed better than the 8% ceramic/AE192 group retaining about 93.4% of the Sample 2 control strength. The strength of the first-class bricks was competitive, but the proposed blocks provide better circular-material benefits by using fly ash and ceramic waste. 5% AE192 is recommended for semi-structural lightweight blocks, while 8–10% AE192 mixes are suitable for non-load bearing sustainable masonry applications.