Investigation of the use of pumice and hemp in concrete

The high specific gravity of conventional concrete leads to some economic and structural disadvantages, making it less suitable for use. In the construction industry, replacing coarse aggregate with pumice stone is one of the most preferred methods to reduce rough loads, improve thermal insulation, increase earthquake resistance and avoid other disadvantages of traditional concrete. Thus, lightweight concrete with low density can be produced. In addition, the need for sustainable building materials today encourages the use of environmentally friendly and renewable resources in concrete production. In this context, hemp sawdust, which is a bio-based product, attracts attention with its light weight, high heat and sound insulation properties. In this study, the use of hemp sawdust and pumice stone together in concrete mixtures was investigated. In the first phase of the research, cube specimens with dimensions of 15×15×15×15 cm were prepared to be used in the experimental study. The reference mix was prepared with 100% pumice stone and 100% cement without the addition of hemp chips. In the other mixes, the proportion of hemp chips was increased by 10%, 20% and 30%, while the proportion of cement was decreased by the same proportions. In all mixtures, fixed proportions of fine aggregate (sand) and water were used with a water/cement ratio of 0.50. In addition, superplasticizer was added at 1% of the cement amount. Slump, unit volume weight, water absorption, compressive strength and SEM-EDX and XRD analysis were performed on the samples. The aim of this study is to reveal the effects of the combined use of hemp sawdust and pumice stone on the mechanical and physical properties of concrete and to contribute to the literature in the field of sustainable building materials. It is thought that the findings obtained will provide important data for the development of alternative and environmentally friendly concrete mixtures.