MODELLING OF THE COMPRESSIVE STRENGTH OF PALM-NUT-FIBRE CONCRETE USING SCHEFFE’S THEORY

Abstract

In this research study, a mathematical model is developed to optimize the palm-nut-fiber reinforced concrete's compressive strength using Scheffe's (5,2) simplex-lattice design. Palm-nut-fiber which is an agricultural residue obtained after the processing of palm-oil is utilized as the fifth component in concrete consisting of water, cement, fine and coarse aggregates. Fibers are used to help fresh concrete to keep it from cracking and plastic shrinkage and also for a concrete structure of complicated or complex geometry where the use of the conventional rebar will not work. The compressive strength of Palm-nut-fiber were obtained for the different componential ratios using Scheffe's Simplex method and for the the control points which will be utilized for the validation of the Scheffe's model. The model's adequacy was tested using student's t-test and ANOVA at 5% critical value. The statistical result indicates a good relationship between the values obtained from the developed Scheffe's model and the control laboratory results. The maximum value of compressive strength of the palm-nut fiber concrete obtained was 31.53Nmm2 corresponding to mix ratio of 0.525:1.0:1.45:1.75:0.6 and minimum value of compressive strength obtained was found to be 17.25Nmm2 corresponding to mix ratio of 0.6:1.0:1.8:2.5:1.2. For water, Limestone Portland cement (LPC), fine aggregate, coarse aggregate and palm nut fiber respectively. Using the developed Scheffe's simplex model, the proportion of the mixture ingredients to a certain prescribed compressive strength value can be estimated with a high degree of accuracy and also providing the solution in less amount of time.