Fly ash in CamelWay concrete production line mainly have three basic function, namely the morphological effect, active effect and micro aggregate effect. Scientific and reasonable use can improve the performance of concrete.
(1) Morphological Effect
The morphology of fly ash is mainly refers to fly ash particle thickness, surface roughness characteristic in the concrete. Beads of fly ash particles can have the effect of ball bearing, reduce the friction in the mixing of concrete and improve liquidity. The density of fly ash is less than cement, thus it can increase the volume of the slurry after the equivalent replacement, improve lubrication degree of aggregate, enhance the liquidity of concrete mixture. Inferior fly ash contained with more irregular porous particles and unburned carbon, resulting in increasing water demand and water retention, a negative impact in concrete batching plant.
(2) Active Role
Fly ash belongs to the active mineral admixture. Fly ash contains the glassy state of silica and alumina which is the active silicon oxide and activated alumina, can have the hydration reaction with cement hydration of calcium hydroxide and water, and generated with hydraulic characteristics hydrated calcium silicate, and hydrated calcium aluminate etc., fill in the capillary porosity. The hydration products have strength too, especially hydrated calcium silicate, the hydration reaction at 28 d weaker, especially within the 7 d, and after 28 d gradually apparent. The fineness of fly ash is larger, (the smaller the particle is, the higher the activity,) hydration reaction ability is higher; the higher the temperature, hydration reaction ability is more stronger, faster growth in strength. When the temperature is lower than 5 , the hydration reaction ended, strength develops slow. Activity function can improve the strength of concrete in the concrete batching plant.
(3) Micro Aggregate Function
Beads of fly ash with high strength, filling the gap between the cement particles, both reduce capillary porosity, and the micro skeleton. With the hydration time, bonding force of hydration products of fly ash and fly ash hydration kernel continues to improve, to improve the micro aggregate effect of fly ash. Reasonable adding fly ash in concrete batching plant, help to improve the output quality of concrete.