| dc.description.abstract | This study investigates the compressive strength performance of high-strength concrete
incorporating fly ash as a partial replacement of cement, with an emphasis on achieving
sustainability without compromising strength characteristics. Although fly ash offers
significant environmental and durability benefits, its use at higher replacement levels is often
associated with reduced early-age strength. To overcome this limitation, the present research
focuses on reducing the water–binder ratio and utilizing a high-range water-reducing
admixture. Concrete mixes were prepared with fly ash replacement levels of 0%, 20%, and
40% by weight of binder. The control mix was designed with a water–binder ratio of 0.283,
while the fly ash blended mixes were produced with reduced water–binder ratios of 0.220 and
0.205, respectively. A Sika high-range water-reducing admixture (HRWR) was incorporated
in all mixes to ensure adequate workability at low water–binder ratios. Cylindrical concrete
specimens were cast and cured under standard conditions, and compressive strength tests were
conducted at 28 days. The results indicate that a reduction in the water–binder ratio
significantly enhances the compressive strength performance of fly ash blended concrete.
Despite the higher fly ash content, the mixes with lower water–binder ratios exhibited
improved strength behavior due to reduced porosity, enhanced particle packing, and a denser
cementitious matrix. The findings demonstrate that the combined use of reduced water–binder
ratio and superplasticizer effectively compensates for the early-age strength reduction
typically associated with fly ash. This approach provides a viable and sustainable method for
producing high-strength concrete while reducing cement consumption. | en_US |
