Effect of binary blended of Portland cement and fly ash to the Strength and Surface Absorption of Concrete

Abstract

The main objective of this paper is to determine the effect of fly ash on the workability, compressive strength , and initial surface absorption test of cement concrete using Portland cement and fly ash as partial replacements for Portland cement at 0%, 5%, 10%, 15% , 20% and 25% for a water-cement ratios(0.38) , the cement concretes have higher initial surface absorption values than Portland cement and fly ash concrete at 28 days and the disparity reduced due to improved pozzolanic reactivity of the supplementary cements with increasing curing age. However, Portland cement and fly ash concrete performed better than Portland cement concrete due to their higher fineness, improved particle packing and higher pozzolanic reactivity. The results showed that the compressive strength of 25% fly ash replacement resulted in concrete with a 28-day maximum strength of 48.25 MPa. and the result showed sample which contained Fly ash has less initial surface absorption and it’s also showed that the concrete containing 5%,10% and 15% of fly ash had less initial surface absorption than other cubes 20% and 25% fly ash.