Effect of moisture content of highly porous bottom ash on properties of concrete mixture and hardened concrete

Research for advantageous utilisation of bottom ash presently formed at thermal power stations by using pulverised coal combustion is being conducted at The Research Institute of The College of Judea and Samaria (Ariel, Israel). It proves the effectiveness of comprehensive use of highly porous bottom ash as aggregate and fly ash as additive for production of lightweight concrete. Proportions, properties and conditions of producing normal weight concrete-comprised fly ash were considered by a number of experiments. However, the problem of using highly porous aggregates with fly ash as an additive is inadequately studied and elucidated in technical publications. One of the main features of these concrete mixtures is a high content of water, resulting in two conditions: (a) absorption of water by highly porous bottom ash particles; and (b) bonding the water to the fine fly ash particles. The goal of this research was to study the proportions and properties of the considered concretes. The research was concentrated on evaluating the effect of moisture content of the bottom ash on the lightweight concrete strength and the concrete mixture proportions. The actual problem depends on using water to sluice off the bottom ash from the furnaces and hydraulic transport at present power stations.