*3.7. Splitting Tensile Strength*

The average results of three 100 mm × 200 mm cylinders that tested for splitting tensile strength are shown in Table 7. The tensile strength of HPSCC was 1.53 times that for NSVC, while HSSCC had a tensile strength of only 14% higher than NSVC, remembering that its compressive strength was 67% higher. When comparing the ratio of tensile strength divided by the square root of compressive strength, NSVC had a value of 0.62, but a higher value of 0.65 was recorded for HPSCC mix, 0.66 for HPVC, and again HSSCC was lower and it was only 0.55. Piekarczyk recorded a ratio of 0.61 for an NSC and 0.65 for an SCC [1]. Others stated that the relationship between tensile and compressive strength of SCC is similar to that of VC [2]. Research showed that the average direct tensile strength of the SCC was found to be 3.5 MPa, whilst the average splitting tensile strength was found to be 3.8 MPa, which is only 8.6% higher [58].


**Table 7.** Splitting tensile strength of Ø100 mm specimens, Flexural strength of 75 mm × 75 mm × 350 mm concrete prisms, and Modulus of Elasticity of Ø150 mm specimens.

### *3.8. Flexural Strength*

The average test results of three 75 mm × 75 mm × 350 mm prisms at age of 90 days were presented in Table 7. HPSCC developed a flexural strength 15% lower than that of HPVC, while it was about 50% higher than both HSSCC and NSVC. The ratio was 0.75 in the case of HPSCC; it was 0.68 for an NSVC and 0.78 for an HPVC. When comparing the results of splitting tensile strength and the flexural strength, it can be noted that the concrete prisms with the higher strength behaved better against tensile stresses than the splitting cylinders.
