Response Surface Analysis of the Compressive Strength of Metakoalin Self-Compacting Concrete

Abstract

This research developed a mathematical model and optimization of materials for the development of metakaolin self-compacting concrete. This is in a bid to reduce the overall material quantity and cost towards sustainable infrastructural construction. To achieve the aim of this research, Response Surface Analysis (RSM) was used. Kaolinitic clay was De-hydroxylated at 750°C to form metakaolin. This was used as a partial replacement for cement at 0%, 5%, 10%, 15%, 20% and 25% weight of Portland limestone cement. Both strength and rheology properties of the developed metakaolin self-compacting concrete were assessed. To this end, slump flow, L-Box test and V-funnel test were carried out alongside the compressive strength using relevant standard. The result of the research revealed that at 15% addition of metakaolin the slump flow, passing ability and filling ability was unsatisfactory according to EFNARC standard. From the numerical optimization of the compressive strength, the maximum predicted compressive strength of 44.35 N/mm 2 was obtained. At a low value of metakaolin addition (5-15%), the compressive strength increased as the age of the concrete increased from 3-150 days. The age with the optimum mechanical strength formation was 110 days with metakaolin addition of 52.73 kg. The result of this research provide a database for Engineers, Researchers and Construction workers on the optimum metakaolin required to achieve satisfactory mechanical strength in metakaolin self-compacting concrete.

Mathematical modelling of concrete compressive strength with waste tire rubber as fine aggregate

“…It has been applied to provide detailed analysis and accurate estimation in the studies of sustainable concrete with replacement materials. Busari [18] applied the RSM analysis to study the properties of concrete with metakaolin and to determine the optimum amount of metakaolin for maximum compressive strength. Rosa et al [19] studied the influence of steel fibre on the fresh and hardened properties of concrete for construction applications.…”

Design of Experiment on Concrete Mechanical Properties Prediction: A Critical Review

“…Meanwhile, other researchers [ 72 , 73 ] used CCD due to its rotatability and ability to predict the result within experimental range with great precision. Of all the literature reviewed, many researchers used the Minitab software to conduct the RSM experimental design and data analysis [ 74 , 75 , 76 ]. Design Expert were also favored by several others [ 68 , 69 ], while one study used the Statistical Analysis System (SAS) to perform the experiment [ 71 ].…”

“…Since BBD and CCD are the two methods provided in Minitab, this may explain why the said methods are frequently adopted. While the RSM is able to handle larger number of variables, most researchers use it to design experiments involving two [ 75 , 77 , 78 , 79 ] or three [ 68 , 69 , 70 ] variables, presumably to make full use of the contour plot, which can represent the effect of two variables as commonly used in design codes such as Eurocode 2 [ 70 ].…”

“…Apart from producing the response surface to study the optimal condition of independent variables that gives the highest performance, researchers frequently perform further analysis to obtain the equation for the prediction of the dependent variable. One method is by conducting ANOVA on the results [ 74 , 75 , 81 ] to determine the significance of each term using Student’s t-test. In this process, terms which are deemed insignificant are removed.…”

Model-Based Methods to Produce Greener Metakaolin Composite Concrete

“…Oluwatobi et al [10] analyzed strength development based on the method of gene expression programming. Ayobami [11] evaluated the strength of self-compacting metakaolin composite concrete using response surface analysis.…”