Concrete Strength Variations of Unwashed and Processed Coarse Aggregate Sizes

Concrete Strength Variations of Unwashed and Processed Coarse Aggregate Sizes

Okoro, R.I, and Ezeagu, C.A

Department Of Civil Engineering Nnamdi Azikiwe University

American Journal of Scientific Research and Essays

This project aims to determine the effect of different coarse aggregate sizes and type on the compressive strength of concrete. The most important property of concrete is its compressive strength. The exceeding strength of concrete is as a result of the presence of coarse aggregate. Normal concrete is being produced from different types of aggregate and size and this imparts different property to the resulting concrete. The research has established that the coarse aggregates and their sizes play critical roles in the development of adequate strength in concrete. Fine aggregate is normal sand obtained from a borrow pit. Preliminary laboratory investigation was conducted to ascertain the suitability of using the aggregates for construction work. Tests conducted include sieve analysis, bulk density, and specific gravity. From the graph of the sieve analysis for fine and coarse aggregate, the coefficient of uniformity calculated was 1.5 and 3.45 respectively. It was observed that with proper mixing, the slump test results did not witness shear or collapse type of slump rather there were true slump in all cases of the test. The result of the slump test for 12.5mm, 19.5mm, and 25mm coarse aggregate were 60, 100, and 90. The workability decreased with slight differences when the coarse aggregate size was increased. Three different sizes of coarse aggregates with 25mm maximum size for both processed (granite) and sand stone (Local stone) were employed in the investigation, namely; 12.5mm, 19.5mm and 25mm. The grading and relative densities of the aggregates were studied. The mix ratio and water / cement ratio adopted for the study was 1:2:4 and 0.5 respectively. Twelve concrete cubes (72 total) (150mm× 150mm×150mm) were cast for each coarse aggregate size and type of which three were crushed at each maturity age namely; 7, 14, 21 and 28 days. The 28 day strength of the concrete made with granite and sand stone of 12.5mm, 19.5mm 25mm were 26.1N/mm^2 , 25.1N/mm^2, 25.2N/mm^2 for processed (granite) and 19.12N/mm^2, 19.10N/mm^2 and 19.90N/mm^2 for sand stone respectively. Consequently, the result confirmed that using processed (granite) as coarse aggregate yield higher strength compared to local stone coarse aggregate.

Keywords: Aggregate, Concrete, Cement, Compressive strength, Sieve.

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How to cite this article:
Okoro, R.I, and Ezeagu, C.A. Concrete Strength Variations of Unwashed and Processed Coarse Aggregate Sizes. American Journal of Scientific Research and Essays, 2018 3:9. DOI:10.28933/ajsre-2018-08-2601


1. Aginam, C. H., Chidolue, C. A., and Nwakire, C., 2013, “investigating the effects of coarse aggregate types on the compressive strength of concrete”. International journal of engineering research and applications, Vol. 3, Issue 4, pp. 1140-1144.
2. Alexander abd Mindess (2008) “Optimum Mix Design for Minimum Concrete Strength Requirement”. Journal of Emerging Trends in Engineering and Applied Sciences (JETEAS) 3 (4): PP 718-724.
3. Alexander and Mindess (2010) The significance of aggregate on concrete.
4. ASTM C 117, 2004. Materials finer than (No. 200) sieve in mineral aggregate by washing. American Society for Testing and Materials.
5. ASTM C 33, 2008. Concrete Aggregates. American Society for Testing and Materials.
6. ASTM C127 and C128, (2012) Standard Test Methods for Density and Specific Gravity, American Concrete Institute.
7. ASTM C127 and C128, (2012), “Standard Test Methods for Density and Specific Gravity”, American Concrete Institute.
8. Ayininuola and Olalusi, (2004) “Optimum Mix Design for Minimum Concrete Strength Requirement”. Journal of Emerging Trends in Engineering and Applied Sciences (JESTEAS) 3 (4): PP 718-724.
9. Bamibgoye (2016) Hardened concrete in exploiting economics of gravel as a substitute to granite in concrete production.
10. BRE 331, 1988. Design of Normal Concrete mixes. Building Research Establishment.
11. BS 1377; Part 2, (1990), “Methods for Test of Soils for Civil Engineering Purposes”, British Standard Institute
12. BS 1881: Part 125: 1986. (2009). Methods for mixing and sampling fresh concrete in the laboratory. British Standards Institution.
13. BS 812; (1995) Methods for Sampling and Testing of Mineral Aggregates, Sands, and Fillers, British Standard Institute
14. BSEN 12390-3, 2009. Testing hardened concrete. 3: Compressive strength of test specimens. British European Standards.
15. Bye, G.L. (1999), “Portland Cement”, 2nd Edition: pp. 206-205, Thomas Telford, ISB NO- 7277-2766-4.
16. Chen and Liu,(2004) as well as Rao and Prasad (2002) Aggregate as skeleton of concrete.
17. Ezeldin and Aitcin (1991) Effect of coarse aggregate type on properties of normal-strength concrete.
18. Gettu, Bazan and Karr (1990) Fracture properties and brittleness of concrete with compressive strength.
19. Giacco, Rocco, Violini, Zappitelli, and Zerbino (1992) Effect coarse aggregate type on the mechanical properties of high-strength concrete.
20. Houssam, A. & Bayasi, z. (1999). Effect of curing procedures on properties of concrete. Cement and Concrete Research, 497-501.
21. Report Civil 2011 @ UNILORIN. Third Annual Conference of Civil Engineering
22. James, T., Malachi, A., Gadzama, E.W., and Anametemfiok, V. (2011) Effects of Curing Methods on the Compressive Strength of Concrete, Nigerian Journal of Technology, Vol. 30(3) pp.14 – 20.
23. Joseph O.U., Maurice, E.E., and Godwin, A.A. (2012) Compressive Strength of Concrete Using Lateritic Sand and Quarry Dust as Fine Aggregate, ARPN Journal of Engineering and Applied Sciences. 7(1)