The use of conversion factor and strength ratio in estimating the strength of basalt rock and basalt aggregate concrete

The aim of this thesis is to examine in detail the conversion factor (k) and the strength ratio (R) on a single type of rock (5 basalts collected from different places in the Black Sea region) and concrete produced from the same rocks at different curing time (2, 7, 14 and 28 day). The average of k value obtained between rocks' uniaxial compressive strength (UCSR) and point load index (PLIR) values was calculated as 17.1. From the literature and this thesis work, detailed research was performed about basalt and it was statistically suggested that k coefficients in the estimation of UCSR could be in the range of 17-20. The strength ratio (R) of the rocks was found to be 10.3 in this study and it was understood that this value has similarity with the literature. When detailed research was done over basalts from the literature and this thesis work, it was seen that the average of R coefficients was 10.5. The effect of curing time over UCSC, PLIC and Brazilian tensile strength (BÇDC) parameters of concrete formed from the basalt aggregates were also investigated. UCSC, PLIC and BÇDC values increased as the curing period increases too. The coefficients of the PLIC parameter in the UCSC estimation varied within a narrow range (7.2–9.5). R ratios obtained from the BÇDC parameter in the estimation of the UCSC varied in a narrow range too (4.3–5.5). The mean k value for all curing times was obtained as 8.2. The mean R value was obtained as 5 for all curing times. It is understood that k and R ratios are approximately 2 times higher in rock samples compared to concrete samples. This study showed that k and R values can be used with caution in preliminary analysis in estimating the strength of basalt and concrete obtained from basalt aggregates.