Research On Producing A Kind Of Green Walling Materials By Shell Ash And Fly Ash

The unfired brick, one of the green walling materials, was produced by using the industrial waste --fly ash and the renewable resource--shell ash as the main raw materials. Several mixture ratios were designed by adjusting the proportion of fly ash, lime, shell ash and cement, and SBR emulsion, sodium silicate, polymer fiber were used to enhance the flexural strength. Meanwhile, different curing methods were also adopted. The experiment contents included the basic mechanical properties test, dry shrinkage test, freezing and thawing cycle test and the dry-wet cycle test. Scanning electron microscopic was used to observe and analyze the Micro-structure. Finally the basalt fiber was substituted for the polymer fiber.The results reveal that there were many different influence factors of mechanical properties. The cement's proportion was quite important and the fly ash's proportion in gelled material could not be exorbitant. The fly ash's early activity could be inspired by adding shell ash to one extent. SBR emulsion and fiber composites could improve the flexural strength, while the sodium silicate had a adverse effect on the compressive strength. The bibulous rate of unfired brick would gradually decrease in the dry-wet circulation, which showed the internal porosity would decrease, and the material had a certain anti-cracking ability. After adding basalt fiber, compressive strength of material was higher than those of the polymer fiber's.The results showed that the brick had the higher flexural strength and compressive strength with an addition of 40% fly ash,20% cement,15% lime,4% plaster and 16% shell ash when incorporating of 3% SBR and 0.1%. The compressive strength was above 20MPa and the flexural strength was above 3MPa. With a high mechanical properties, low shrink, and low energy consumption, this new material has a good prospect.