Optimization of Compressive Strength of Polystyrene Lightweight Concrete Using Scheffe‟s Pseudo and Component Proportion Models

International Journal of Civil Engineering

© 2020 by SSRG - IJCE Journal

Volume 7 Issue 6

Year of Publication : 2020

Authors : Ubi, Stanley E., Okafor, F. O, Mama, B. O

10.14445/23488352/IJCE-V7I6P103

How to Cite?

Ubi, Stanley E., Okafor, F. O, Mama, B. O, "Optimization of Compressive Strength of Polystyrene Lightweight Concrete Using Scheffe‟s Pseudo and Component Proportion Models," SSRG International Journal of Civil Engineering, vol. 7,  no. 6, pp. 21-35, 2020. Crossref, https://doi.org/10.14445/23488352/IJCE-V7I6P103

Abstract:

Expanded polystyrene beads are industrial waste that can be used for the construction of lightweight concrete. Although the major setback in the use of this material has been the challenge of obtaining a reliable compressive strength of the associated concrete suitable for residential and commercial purposes. This often comes with multiple trail mixes that are time-consuming and cost-intensive, hence the need to develop a mathematical model that will optimize the compressive strength of polystyrene lightweight concrete. The materials used for this study were (i) Ordinary Portland cement (ii) Water (iii) Sand (iv) coarse aggregate and (vi) Expanded Polystrene beads. The materials were batched according to their weights, except for coarse aggregates and polystyrene beads which were mixed and batched together as a single material in the volume. Thus, giving a total of four components instead of five. The study adopted Scheffe’s simplex lattice design for both pseudo and component proportion models to generate their respective mixes. The first 10 mixes from each model served as the actual mixes, while the last 10 served as the control mixes. The constituents were manually mixed in the laboratory and the results used for model optimization were based on the 28th-day test. All specimens were cured based on NIS 87 (2004). The laboratory compressive results for the 28th-day test were obtained. The study showed that using Scheffe’s Pseudo component model, an optimized compressive strength value of27.920 N/mm2 can be obtained from water, cement, sand, and coarse aggregate (at 12% partial replacement with polystyrene aggregates) mix ratio of 0.455, 1, 1.820, and 2.980 respectively. On the other hand, Scheffe’s component proportion model showed that compressive strength of 27.550 N/mm2 can be attained from water, cement, sand, and coarse aggregate (at 12% replacement) mix ratio of 0.482, 1, 1.850, and 3.360 respectively. The results from the two models show that polystyrene lightweight concrete can attain a concrete strength that is suitable for residential purposes and can also be used as partitions in high rising buildings due to their lightweight.

Keywords:

Lightweight, Concrete, Mathematical Optimization, Polystyrene, Scheffe’s Model, and Compressive Strength.

References:

[1] Chen, B., & Liu, J. Mechanical properties of polymer-modified concrete containing expanded polystyrene beads. Construction and Building Materials, 21(1)(2007) 7-11.
[2] Chen, B., & Liu, N.. A novel lightweight concrete-fabrication and its thermal and mechanical properties. Construction and building materials, 44(2013) 691-698. [3] Kan, A., &Demirboğa, R. A novel material for lightweight concrete production. Cement and Concrete Composites, 31(7), (2009) 489-495.
[4] Madedor, A.O.,. The impact of building materials research on low-cost housing development in Nigeria. Engineering focus, Publication of the Nigerian Society of Engineers, 2(2)(1992).
[5] Komolafe, O. S. A study of the alternative use of laterite-sand-cement. A paper presented at the conference on Materials Testing and Control, University of Science and Technology, Owerri, Imo State. (1986).
[6] Cornell, J., Experiments with Mixtures: Designs, Models, and the Analysis of Mixture Data.3ed. John Wiley and Sons Inc. New York. (2002).
[7] Piepel, G. F., and Redgate T. A mixture experiment analysis of the Hald cement data. The American Statistician, 52(1998) 23 – 30.
[8] Goelz, J. C. G. Systematic experimental designs for mixed-species plantings. Native plant Journal, 2(1)(2001).
[9] Scheffe, H. Experiment with mixtures. Journal of Royal Statistics Society. Series B, 20(2)(1958) 344 – 360.
[10] EN, B. 1008 Mixing Water for Concrete. British Standards Institution: London, UK. (2002).
[11] Nigerian Industrial Standard. (NIS 87:2004). The standard for concrete blocks, standards organization of Nigeria, Lagos, Nigeria.
[12] BS EN 12390-4:2000 Testing hardened concrete. Compressive strength specifications for testing machines. British Standard Institution, London.
[13] EN, B. 206: 2013. Concrete. Specification, performance, production, and conformity. (2013).
[14] ASTM, C. 39 Standard test method for compressive strength of cylindrical concrete specimens. Annual Book of ASTM Standards. ASTM American Society for Testing and Materials, West Conshohocken, PA, USA. (2001).