EVALUATING THE COMPRESSIVE STRENGTH AND MICROSTRUCTURAL PROPERTIES OF CONCRETE ADMIXED WITH CASSAVA PEEL ASH AND GRANITE DUST AS PARTIAL REPLACEMENTS FOR CEMENT

The study investigated the compressive strength and microstructural properties of concrete admixed with cassava peel ash and granite dust as partial replacements for cement. Cassava peel and granite dust are produced on a daily basis, and the inadequate management of granite waste, along with a lack of sufficient landfills for cassava waste, poses a significant challenge. This research aims to transform these waste materials into valuable construction resources. The study examines how Cassava Peel Ash (CPA), Granite Dust (GD), and Curing Days (CD) affect the compressive strength (C.S) of grade 20 concrete. A Box-Behnken design was employed to assess the C.S, with CPA, GD, and CD ranging from 2 – 6%, 4 – 8%, and 3 – 56 days, respectively. The findings indicated that CPA, GD, and CD significantly influence compressive strength of the concrete. The results of the optimization indicate that the best combination of factors for achieving maximum Compressive Strength consists of 4% CPA, 7% GD, and a curing duration of 42 days, which predicts compressive strength value of 25.8 N/mm2 . A mathematical model was developed based on the relationships between the input factors and the resulting compressive strength. Furthermore, the microstructure of the concrete with additives was analyzed using a scanning electron microscope(SEM) at a magnification of X1500. This research highlights the effectiveness of employing Box-Behnken design to enhance concrete mix design and boost its compressive strength. According to the results of this research, the optimal mix of 2% Cassava Peel Ash, 4% Granite Dust, and a curing period of 42 days can effectively produce concrete grade 20 with enhanced compressive strength.