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Nwa-david, C. D.
Department of Civil Engineering, Michael Okpara University of Agriculture, Umudike, Abia State, Nigeria
Adenaike, O. A.
Department of Civil Engineering, , Federal Polytechnic Ngodo-Isuochi, Abia State, Nigeria.
Ukachukwu, O. C.
Department of Civil Engineering, Federal University of Technology, Owerri, Imo State, Nigeria.
ABSTRACT
The
construction industry in developing nations is constantly concerned with
achieving viable low-cost eco-friendly infrastructural buildout considering the
rising cost of concrete materials, reduction in material’s availability and
quality, as well as their environmental impact. This paper investigated the use
of cow dung ash (CDA) as a partial replacement material for cement in concrete
production. The concrete was produced with a mix ratio of 1:1.5:3 and
water-cement ratio of 0.6. Particle size analysis, Specific gravity,
workability and setting time tests were carried out on the constituent
materials. The partial replacement of cement with CDA was done at 2.5%
interval. A total of thirty-three 150 × 150 × 150 mm’ concrete cubes were made
and compressive strength test was done after 28 curing days. The compressive
strength of CDA-concrete at 28-day curing increased consistently from 0% cement
replacement with CDA to 20% replacement with CDA and decreases gradually beyond
20% cement replacement with CDA. Ibearugbulem’s method was employed to
formulate a mathematical model for prediction and 28 days’
strength-optimization of CDA-cement composite. The response function is
expressed as a multivariable function for the proportions of the constituent
materials, considering the spatial domain for each concrete mixture variable.
Applying the variational approach, the response function was developed within
the specified spatial domain and was optimized. The percentage variation between the optimum
experimental and model predicted strength is 3.6% which demonstrates the
reliability of the model and its ability to generate close form solution. Evaluating the adequacy of the model with student’s
T-test at 95% confidence level, proved that the model is worthy of adoption for
reliable, time-effective and accurate strength-optimization of CDA-cement
concrete.
Keywords: Concrete, Cow Dung Ash (CDA), Compressive Strength, Ibearugbulem Model, Optimization.
https://doi.org/10.33922/j.ujet_v10i2_8
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Published
Wednesday, August 21, 2024
Issue
Vol. 10 No. 2, December 2024
Article Section
GENERAL
The contents of the articles are the sole opinion of the author(s) and not of UJET.
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