USE OF HIGH VOLUME FLY ASH ON EARLY AGE SHRINKAGE IN CONCRETE FOR LOCAL HOT AND DRY CONDITION

Abstract

Recently contractors are demanding a reliable and all-weather partial or full replacement material for sand due to government restrictions on natural sand mining from river beds. Many previous studies showed that fly ash as a pozzolanic material is effective for improving the various properties of concrete. Advantages of fly ash as partial replacement of cement in concrete on early age shrinkage are reported in standard literature. However, effect of fly ash as partial replacement of cement and sand in concrete on early age shrinkage is not clearly available in reputed literature. This paper discusses the experimental research carried out on early age shrinkage of concrete mixtures in which cement and sand were partially replaced with high volume class F fly ash. Nine mixes were prepared that is C0-0, C20-0, C40-0, C0-20, C0-40, C20-20, C20- 40, C40-20 & C40-40 by partly replacing cement and sand by fly ash and compared with control concrete at an early age by using shrinkage cone apparatus. Combine replacement up to 40% of cement and 20% sand by fly ash respectively gives the better result than other mixes. Combine replacement 40% cement and 40% sand by fly ash has reduced the shrinkage by 63.13% than the control mix. In general, incorporation of fly ash as a partial replacement of cement and sand reduced the shrinkage properties and adds sustainability to concrete by reducing CO2 emission during cement production.

Keywords

• Durability
• Early age
• Shrinkage fly ash
• Sand
• and Sustainable
• Sustainable