OPTIMIZATION AND PROGNOSTIC MODEL FOR SPLITTING TENSILE STRENGTH OF CONCRETE PRODUCED FROM GRANITE AND RECYCLED CONCRETE AGGREGATE

S. O. Odeyemi; O. D. Atoyebi; F. O. Adua

S. O. Odeyemi Department of Civil and Environmental Engineering, Kwara State University, Malete
O. D. Atoyebi Department of Civil Engineering, Landmark University, Omu-Aran
F. O. Adua Landmark University SDG 11 (Sustainable Cities and Communities Research Group

Keywords: Concrete, Model, Optimization, Recycled Concrete Aggregate, Splitting Tensile Strength, Civil Engineering

Abstract

Using recycled concrete aggregates from structural demolition wastes is presenting a potential application in the building industry as a substitute for natural aggregates. It preserves natural resources and brings about a reduction in the space needed as landfill disposal sites. This research was aimed at developing a prognostic model for splitting tensile strength of concrete produced from granite and recycled concrete aggregate. Thirteen rounds of experiments were considered utilizing the Central Composite Response Surface method. Granite was replaced with Recycled Concrete Aggregate (RCA) in varying proportions from 0% to 100% while the water-cement ratio (w/c) was varied from 0.3 to 0.7. Samples were subjected to test after 7, 14 and 28 days curing. It was observed that with a surge in the fraction of RCA, the splitting tensile strength reduced at all levels of w/c ratio. 30% RCA at 0.5 w/c gave the optimum combination that resulted in the highest splitting tensile strength of 2.11 at 28 days. This result is 7.9 % lesser than the control splitting tensile strength of 2.29