The paper presents a laboratory study to determine the relationship between compressive strength of no-fines concrete (NFC) and its tensile strength measured both by double-punch test and modulus of rupture test methods. The compressive strength was carried on 100 x 100 x 100 mm cubes. The specimens for tensile strength tests were 150 x 150mmcylinders, and 100 x 100 x 500 mm beams. Crushed limestone was used as coarse aggregate with max size of 19 mm. Sixteen concrete mixes were prepared with water-to-cement ratios: 0.40; 0.42; 0.44; and 0.46 cement-to-aggregate ratios (C/A) 1 : 5, 1 : 7, 1 : 9 and 1 : 11. The total of 48 cubes, 48 cylinders, and 48 beams were prepared. Compressive and tensile strength tests were carried on the concrete specimens according to relevant standards ASTMC39/ C39M. 2016 andASTM-C78/C78M. 2015 and the average of three results was recorded each time. It was found that tensile strength measured by modulus of rupture test gave higher results than that measured by double-punch test. The tensile strength from the double-punch test was about 20% of the compressive strength and from the modulus of rupture was about 30% of the compressive strength according to test results obtained in this study.
Keywords: no-fines concrete, laboratory study, compressive and tensile strength.