Difference between strength by Schmidt hammer test and destructive compressive test of concrete having partial replacement of sand by marble dust

Abstract

Concrete is a mixture of aggregate, cement and water and plays a dynamic role in infrastructure development. The
problem we are facing is a growing demand for industrial production and an increase in the consumption of aggregates,
which immediately led to a decrease and a lack of aggregates. This situation must show new specific options for researchers.
Because of the large amount of marble is produced. During the formation, the marble is ground and marble dust is obtained
as a by-product. This study focuses on the performance of marble dust as a partial substitute of sand in concrete mixtures.
The purpose of this study was to study the effect of marble dust on the strength of concrete as a partial substitute for fine
aggregate (sand) in concrete and also to study the difference in strength between the Schmidt hammer and the destructive
test. Marble Concrete was obtained by replacement of marble dust with 5%, 10%, 15%, 20%, 25% and 30% to fine
aggregates led to the formation of cylindrical concrete samples and finally compared to the control of cylindrical concrete
samples. Cylindrical concrete samples were casted and cured and compression tests were performed for 14 and 28 days
using the Schmidt hammer test and the destructive compression test using standard test procedure. The study shows that
substitutes to marble powders of 5%, 10%, 15%, 20%, 25% and 30% as fine aggregates increase the compressive strength of
normal concrete. The maximum value of this unit is 10% in 14 days and 10% in 28 days. By comparing the difference in
strength between the Schmidt hammer test and the destructive compression test, the average strength difference between for
14 and 28 days was 17.2% and 14.9% respectively