Utilizing of Magnetized Water in Enhancing of Volcanic Concrete Characteristics

Abstract

Volcanic concrete is an eco-friendly concrete type in that it contains coarse and fine aggregates that all extracted from the igneous volcanic rock. However, utilizing of volcanic ash (VA) as partial/full replacement of concrete cement significantly affects the concrete workability, especially at high cement replacement ratios. This has also some adverse effects on concrete strength. Utilizing magnetized water (MW) in concrete as a partial/full replacement of ordinary tap water (TW) has a notable effect on enhancing the fresh and hardened concrete properties. This research aims to study the effect of using MW prepared in a magnetic field of 1.4 Tesla on the workability and hardened properties (compressive, tensile, and flexural strengths) of volcanic concrete. In this study, VA partially replaced volcanic concrete cement with ratios of 5%, 10%, 15%, and 20%. Ten volcanic concrete mixes were prepared in two groups. The first one was prepared with VA (0–20%) and mixed with TW. The other group was prepared with the same VA contents like group one, but mixed with MW. Microstructure imaging for volcanic concrete was also conducted in this study. Results of water tests showed 17% and 15% increase in total dissolved solids (TDS) and pH, respectively, of MW compared with those of TW. In addition, the water magnetization decreased the water surface tension by 7% compared with that of TW. Results of hardened concrete tests showed that the best ratio of VA in volcanic concrete was 5% with and without using magnetized water. The volcanic concrete slump decreased when using TW; however, using MW enhanced the volcanic concrete slump by up to 8%. The compressive strength was improved by 35%, 23%, and 20% at 7 days, 28 days, and 120 days, respectively, with no VA and with the presence of MW. The compressive strength was improved by 11%, 12%, and 11% after 7 days, 28 days, and 120 days, respectively, with using 5% VA and with the presence of MW. Both splitting tensile strength and flexural strength of volcanic concrete with and without VA or MW behaved similar to that of the corresponding compressive strength.