Possibility of Testing the Compressive Strength of Concrete on the Halves of Prisms Specimens

Year 2020, Volume: 11, 41 - 47, 31.12.2020

Ana Romıć Sandra Juradın Nives Ostojıć-škomrlj Marko Beretın

Abstract

Compressive strength, as the main mechanical property of the building materials, depends on geometrical characteristics of the tested specimens: cube, cylinder or prism. Unlike concrete strength tests, where different specimens are used to determine compressive and flexural strength, those values are tested on the same prism specimens for the cement mortar. The purpose of this study is to investigate the possible correlation between values of compressive strength obtained on half concrete prism (10 cmx10 cmx40 cm) after flexural test with compressive strength on standardized 15 cm and 10 cm cubes. Three concrete mixtures have been tested and every mixture had a different maximum grain size of aggregate, namely 8 mm, 16 mm and 31,5 mm. Same type and quantity of the cement are used in all mixtures with the same water/cement ratio. The workability of the fresh concrete was examined by using the slump-flow method. Nine specimens are prepared for each concrete mixture; three for every dimension. According to the obtained results, it can be assumed that there is a significant level of connection of compressive strength values between half-prism and both 10 cm and 15 cm cube specimens. Results showed there is a possibility of using half-prism concrete specimens after the flexural test for the evaluation of compressive strength. This would reduce the number of test samples and the problem of sample disposal after the test.

Keywords

Compressive strength, Flexural strength, Size of the test specimen, Concrete

References

• Beretin, M. (2020). Utjecaj veličine ispitnog tijela i maksimalnog zrna agregata na mehaničke karakteristike očvrslog betona, Diploma work, Faculty of Civil Engineering, Architecture and Geodesy, University of Split, Croatia (in Croatian)
• Day, R.L. (1994a). Strength Mesurement of concrete using different cylinder sizes: A statistical analysis, Cement, Concrete and Aggregates, 16, 21-30.
• Day, R.L. (1994b). The effect of mold size and mold material on compressive strength mesurement using concrete cylinders, Cement, Concrete and Aggregates, 16, 159-166.
• Del Viso, J.R., Carmona, J.R., Ruiz G. (2008). Shape and size effects on the compressive strength of high-strength concrete, Cement and Concrete Research, 38(3): 386-395.
• Haktanir T., Karaboga D., Akay B. (2012). Mix Proportioning of aggregates for concrete by three different approaches. Journal of Materials in Civil Engineering, 24(5):529-537.
• HRN EN 12350-2 (2019). Testing fresh concrete -- Part 2: Slump-test
• HRN EN 12390-1 (2012). Testing hardened concrete -- Part 1: Shape, dimensions and other requirements for specimens and moulds
• HRN EN 12390-2 (2019). Testing hardened concrete -- Part 2: Making and curing specimens for strength tests
• HRN EN 12390-3 (2019). Testing hardened concrete -- Part 3: Compressive strength of test specimens
• HRN EN 12390-5 (2019). Testing hardened concrete -- Part 5: Flexural strength of test specimens
• HRN EN 196-1 (2016). Methods of testing cement -- Part 1: Determination of strength
• HRNEN 12504-4 (2004). Testing concrete -- Part 4: Determination of ultrasonic pulse velocity
• Kumari, R. (2015). Review paper based on the relation between the strength of concrete cubes and cylinders, International Journal of Engineering Research and Applications, 5(8): 52-54.
• Matulić, P., Juradin, S., Marušić, E., Domazet, A. (2016). Effect of test specimen size on mechanical properties of shotcrete, Građevinar. 68(4): 301-309.
• Neville, A.M. (1995). Properties of concrete, Pearson Education Limited, England.
• Sabnis, G.M., Mirza, S.M. (1979). Size effect in Model Concretes. Journal of the Structural Division, 105, 1007-1020.
• Śliwiński J., Duźy P. (2020). Impact of sample size and maximum aggregate grain on the representativeness of concrete samples, Energies, 13, 3358.
• Zabihi, N., & Eren O. (2014). Compressive strength conversion factors of concrete as affected by specimen shape and size, Research Journal of Applied Sciences, Engineering and Technology, 7(20):4251-4257.