The development of high volume rice husk ash （RHA） alumino silicate composites （ASC） was studied. RHA was used as the source of silica and aluminium in the ASC. The mass ratios of RHA：Al（OH）3 of 70：30 to 99：1...The development of high volume rice husk ash （RHA） alumino silicate composites （ASC） was studied. RHA was used as the source of silica and aluminium in the ASC. The mass ratios of RHA：Al（OH）3 of 70：30 to 99：1 were tested. The results indicate that the obtained ASC mortars are not stable and disintegrate in water. Boric acid was introduced to the mixture to overcome this problem. Stable ASC mortars with high RHA：Al（OH）3 mass ratios of 90：10 to 97.5：2.5 were obtained with the use of boric acid and 115oC curing. The compressive strength of the mortar of 20 MPa was gained. The immersion test indicates that high volume RHA ASC mortars show good resistance in 3vol% H2SO4 solution, but is slightly less durable in 5wt% MgSO4 solution.展开更多
The deterioration of concrete by sulfuric acid attack in sewage environments has become a serious problem for many existing sewage structures. In this study, the properties of concrete using the blast furnace slag hav...The deterioration of concrete by sulfuric acid attack in sewage environments has become a serious problem for many existing sewage structures. In this study, the properties of concrete using the blast furnace slag have been examined. It was shown that by using the blast furnace slag fine aggregate and blast furnace slag fine powder, it is possible to enhance the resistance of mortar and concrete to sulfuric acid. The resistance to sulfuric acid of mortar and concrete can be improved by using a blast-furnace slag fine aggregate in the total amount of fine aggregate. When mortar or concrete reacts to sulfuric acid, dihydrated gypsum film is formed around the particulate of the fine aggregate. This dihydrated gypsum film could retard the penetration of sulfuric acid, thus, improving the resistance to sulfuric acid. Furthermore, it has been proved that the relationship between the erosion depth by sulfuric acid attack and the product of immersion period and concentration of sulfuric acid can be expressed linearly. However, this relationship is dependent on the type of materials of concrete.展开更多
文摘The development of high volume rice husk ash （RHA） alumino silicate composites （ASC） was studied. RHA was used as the source of silica and aluminium in the ASC. The mass ratios of RHA：Al（OH）3 of 70：30 to 99：1 were tested. The results indicate that the obtained ASC mortars are not stable and disintegrate in water. Boric acid was introduced to the mixture to overcome this problem. Stable ASC mortars with high RHA：Al（OH）3 mass ratios of 90：10 to 97.5：2.5 were obtained with the use of boric acid and 115oC curing. The compressive strength of the mortar of 20 MPa was gained. The immersion test indicates that high volume RHA ASC mortars show good resistance in 3vol% H2SO4 solution, but is slightly less durable in 5wt% MgSO4 solution.
文摘The deterioration of concrete by sulfuric acid attack in sewage environments has become a serious problem for many existing sewage structures. In this study, the properties of concrete using the blast furnace slag have been examined. It was shown that by using the blast furnace slag fine aggregate and blast furnace slag fine powder, it is possible to enhance the resistance of mortar and concrete to sulfuric acid. The resistance to sulfuric acid of mortar and concrete can be improved by using a blast-furnace slag fine aggregate in the total amount of fine aggregate. When mortar or concrete reacts to sulfuric acid, dihydrated gypsum film is formed around the particulate of the fine aggregate. This dihydrated gypsum film could retard the penetration of sulfuric acid, thus, improving the resistance to sulfuric acid. Furthermore, it has been proved that the relationship between the erosion depth by sulfuric acid attack and the product of immersion period and concentration of sulfuric acid can be expressed linearly. However, this relationship is dependent on the type of materials of concrete.
