Daily variation measurement of water and air temperatures inside the semi-full water storage tanks which have solid and porous concrete walls

Nowadays, access to safe drinking water is a major challenge in most arid and semi-arid regions of the world. Due to the low cost of raw materials for construction of concrete tanks, these types of structures are common in many areas where water problems are encountered. This study explores the use of porous concrete by utilizing the idea of old water storage tanks (Ab-Anbars), which played an important role in water storage for remote areas, rural and small towns until three to four decades ago, and their effect on reducing or increasing water temperatures. At the wall of the water storage tanks, effect of air passage through the porous concrete on the water inside the tanks is studied. For further investigation, LECA (5% by weight of aggregates) was used as an additive to porous concrete and 3 replicates of this treatment and control treatment were made. Daily ambient temperature and humidity were measured by the respective sensors, and inside temperature of the tanks was measured with two sensors, one in the middle of the stored water and one in the middle of the open space of the tanks, in the warmest hour of the day (14:30 pm) in spring and summer of 2019. Results showed that mean water temperature of LECA treatment was lower than mean water temperature of control and mean air temperature of control treatment was higher than mean air temperature of LECA treatment. Mean air and water temperatures were always less than mean ambient temperature. Also, the physical parameters of porous concrete (i.e., porosity, permeability and compressive strength) were investigated in this study. Results showed that the compressive strength and porosity of LECA treatment were higher than the control and its permeability was lower than the control.