Flexural analysis of lightweight concrete blocks made from substitution of fly ash

Abstract

This study was conducted to determine the flexural strength of lightweight concrete in combination with fly ash. The use of fly ash in this study to replace the volume of cement using a different percentage rate of 25%, 50% and 75%. This study shows the results of the sample at 7, 14 and 28 days. Specimens used in this study using the mould size 500 mm x 100 mm x 100 mm. The experimental results are compared with the usual lightweight concrete samples with the same characteristics. The results obtained show that the lightweight concrete with the addition of 50% fly ash has a high flexural strength at 7 and 28 days compared to normal lightweight concrete. On 7th day, concrete sample is the highest the flexural strength compared with the concrete mixed with fly ash. The flexural strength of fly ash mixture of 75% was the lowest on day 7. Mixture of 25% fly ash had the lowest flexural strength, while a mixture of 50% fly ash had the highest flexural strength on day 14. For the flexural strength on the day 28, the flexural strength of fly ash mixture of 50% is the highest compared to other mixtures of fly ash and concrete samples.