Effect of concrete class, maximum aggregate size and specimen size on the compressive strength of cores and cast specimens

• Autorzy: Merabti Salem

Identyfikatory

DOI

10.2478/adms-2022-0016

• Języki publikacji: EN

Abstrakty

EN

Core sampling is the most accurate method of evaluating the compressive strength of concrete structures. However, it is preferable to take only small cores to avoid damaging the structures. It turns out that various elements influence the strength of compressed cores. This study examines the influence of specimen size, aggregate size, concrete class, and curing method on compressive strength. Three aggregates measuring 3/8, 8/15, and 15/25 mm are used to make six sets of concrete compositions with strengths of 25 MPa and 30 MPa. Nine specimens are made, one for each variety of aggregate and concrete. Cores of 100 mm, 75 mm, and 50 mm sizes are made. These cores are extracted from concrete blocks curing in the outside air to simulate the real concrete curing environment. Cast specimens cured in water and air with diameters of 50 mm, 100 mm, and 150 mm are also made. The objective is to compare the average compressive strength of all cast or extracted specimens with that of cylindrical standard specimens of diameter 150/300 mm and the cores and cast specimens. The obtained findings showed that the compressive strength is overestimated when we compare fp100 cores and standard air-cured specimens (fc), with a conversion factor varying from 0.69 to 0.96. However, a decrease is observed in comparison with water-cured specimens. The use of fp75 cores reduced the conversion factors, which are between 0.83 and 0.87 for B25 concrete. The highest fp/fc ratios are obtained for fc50 cores, which can reach 1.24. It turns out that the size of the core and the class of concrete have a much greater influence on the fp/fc ratios.

Słowa kluczowe

EN

concrete; compressive strength; cast; specimen; cores; aggregate size; specimen size

PL

beton; wytrzymałość na ściskanie; próbki odlewu; rdzenie; wielkość próbki

• Wydawca: Politechnika Gdańska
• Czasopismo: Advances in Materials Science
• Rocznik: 2022
• Tom: Vol. 22, nr 4(74)
• Strony: 21--31
• Opis fizyczny: Bibliogr. 28 poz., rys., tab., wykr.

Twórcy

autor

Merabti Salem

• Laboratory of Acoustics and Civil Engineering, Faculty of Science and Technology, University Djilali Bounaama of Khemis-Miliana, Algeria

Bibliografia

• 1. Amini K., Jalalpour M., Delatte N: Advancing concrete strength prediction using non-destructive testing: development and verification of a generalizable model. Construction and Building Materials 102 (2016) 762-768.
• 2. Fladr J., Bílý P: Specimen size effect on compressive and flexural strength of high-strength fibre-reinforced concrete containing coarse aggregate. Composites Part B-Engineering 138 (2018) 77-86.
• 3. Thermou GE., Hajirasouliha I: Compressive behaviour of concrete columns confined with steel-reinforced grout jackets. Composites Part B-Engineering 138 (2018) 222-231.
• 4. Indelicato F: A statistical method for the assessment of concrete strength through microcores. Materials and Structures 26 (1993) 261-267.
• 5. ASTM C42/C 42M-04. Standard test of obtaining and testing drilled cores and sawed beams of concrete, American Society for Testing and Materials. 2004.
• 6. EN 13791:2007. Assessment of in-situ compressive strength in structures and precast concrete components, September 2007.
• 7. ISO/DIS 7032. Cores of hardened concrete-Taking examination and testing in compression, Draft International Standard, International Organization of Standardization. 1983.
• 8. DIN 1048 Teil 2. Prüfverfahren Ftir Beton. Bestimmung der Bruchfestigkeit von Festbeton in Bauwerken und Bauteilen, (Deutsches Institut Ftir Normung, Berlin. 1991.
• 9. ACI Committee 301. Specification for Structural Concrete for Buildings. ACI 301-84 American Concrete Institute, Detroit. 1984.
• 10. Seong-Tae Y., Eun-Ik Y., Joong-Cheol C: Effect of sizes, specimen shapes, and placement directions on compressive strength of concrete. Nuclear Engineering and Design 236 (2006) 116-127.
• 11. Indelicaton F: Estimation of concrete cube strength by means of different diameter cores: A stastical approach. Materials and Structures 24 (1997) 131-138.
• 12. Nedjar B: Damage mechanics: first gradient theory and application to concrete. PhD Thesis. National School of Bridges and Roads. Paris. France. 1995.
• 13. Alwash M., Breysse D., Sbartaï ZM: Nondestructive strength evaluation of concrete: analysis of some key factors using synthetic simulations. Construction and Building Materials 99 (2015) 235-245.
• 14. Ali-Benyahia K., Sbartai ZM., Breysse D., Kenai S., Ghrici M: Analysis of the single and combined non-destructive test approaches for on-site concrete strength assessment: general statements based on a real case-study. Case Studies in Construction Materials 6 (2017) 106-119.
• 15. Ali-Benyahia K., Sbartaï ZM., Breysse D., Ghrici M., Kenai S: Improvement of nondestructive assessment of on-site concrete strength: Influence of the selection process of cores location on theassessment quality for single and combined NDT techniques. Construction and Building Materials 195 (2019) 613-622.
• 16. Bungey JH: Determining concrete strength by using small diameter cores. Magazine of Concrete Research 31 (1979) 91-98.
• 17. Bocca P: Sul microcarotaggio - Basi teoriche e prime esperienze. La Prefabbricazione 22(1986) 651-664.
• 18. Bocca P., Indelicato F: Size effects and statistical problems of microcores in the re-evaluation of existing structures. In Proceedings of DABI Symposium, Copenhagen, pp. 463-472. June 1988.
• 19. Elices M., Rocco C.G: Effect of aggregate size on the fracture and mechanical properties of a simple concrete. Engineering Fracture Mechanics 10 (2008) 2-11.
• 20. Sima J., Yangb K.H., Jeonc J.K: Influence of aggregate size on the compressive size effect according to different concrete types. Construction and Building Materials 44 (2013) 716-725.
• 21. Jin L., Yu WX., Du XL., Zhang S., Li D: Meso-scale modelling of the size effect on dynamic compressive failure of concrete under different strain rates. International Journal of Impact Engineering. 125 (2019) 1-12.
• 22. Wu ZY., Zhang JH., Yu HF., Ma HY: 3D mesoscopic investigation of the specimen aspect-ratio on coral aggregate concrete. Composites Part B-Engineering 198 (2020) 108025.
• 23. Jin L., Yu WX., Du XL., Yang WX: Meso-scale simulations of size effect on concrete dynamic splitting tensile strength: influence of aggregate content and maximum aggregate size Engineering. Fracture Mechanics 230 (2020) 106979.
• 24. Jin L., Yu WX., Du XL., Yang WX: Mesoscopic numerical simulation of dynamic size effect on the splitting-tensile strength of concrete. Engineering Fracture Mechanics 209(2019) 317-332.
• 25. Wang X., Zhang S., Wang C., Song R., Shang C, Fang X: Experimental investigation of the size effect of layered roller compacted concrete (RCC) under high-strain-rate loading. Construction and Building Materials 165 (2018) 45-57.
• 26. Li M., Hao H., Shi Y., Hao Y: Specimen shape and size effects on the concrete compressive strength under static and dynamic tests. Construction and Building Materials 161 (2018) 84-93.
• 27. Zhangyu W., Jinhua Z., Hongfa Y., Haiyan M., Li C., Wen D., Yi H., Yadong Z: Coupling effect of strain rate and specimen size on the compressive properties of coral aggregate concrete: A 3D mesoscopic study. Composites Part B-Engineering 200 (2020) 108299.
• 28. BS 1881: Part 110, Part 110. Method for making test cylinders from fresh concrete, British Standard Institution, London. 1983.

Uwagi

Opracowanie rekordu ze środków MEiN, umowa nr SONP/SP/546092/2022 w ramach programu "Społeczna odpowiedzialność nauki" - moduł: Popularyzacja nauki i promocja sportu (2022-2023).