ABSTRACT

In this research work, the mechanical properties, durability and stiffness parameters of concrete in which the concrete component was partially replaced with cassava peel ash (CPA) were investigated. The replacement level of cement with CPA ranges from 0 – 40% at the hydration period of 3, 7, 28, 60 and 90 days respectively. The chemical analysis of CPA shows that it contain SiO₂ (55.93%), Fe₂O₃ (6.02%) and Al₂O₃ (19.93%) among other oxides. The sum total of SiO₂, Fe₂O₃ and Al₂O₃ is greater than 70% minimum prescribed by ASTM C618 – 78 which indicates that CPA can be used as a pozzolan. The pozzolanic activity index (PAI) of CPA is 75.8% which is also an indication that it has very high remarkable pozzolanic properties. The results of compressive strength of 5 – 40% replacement of cement with CPA range from 12.56N/mm² to 33.26N/mm² as against 13.93N/mm² to 35.23N/mm² for the control test. The result of flexural strength of 5 – 40% replacement of cement with CPA range from 3.33N/mm² to 15.17N/mm² as against 4.67N/mm² to 16.80N/mm² for the control test (0% replacement). The initial setting time of 5% to 40% replacement of cement with CPA range from 55minutes to 123minutes as against 52minutess for the control test. The final setting time of the cement with CPA at the same replacement level range from 596minutes to 788minutes as against 591minutes for the control test. The young’s modulus of elasticity for 5% to 40% replacement of cement with CPA range from 22572.09 N/mm² to 31124.51 N/mm² as against 23352.50 N/mm² to 31721.31 KN/m² for the control test. The modulus of rigidity of 9405.038 N/mm² to 12968.55 N/mm² as against 9730.208N/mm² to 13217.21 N/mm² for the control test.