| dc.description.abstract | The reductive slag and slag fine aggregates are the by-products of EAF steel-making. After an appropriate process, reductive slag can show a similar cementation effect as the cement, and slag fine aggregates can be used in certain cases to replace part of the natural aggregates after the pre-processing is made. If we can combine both products to make environmentally friendly concrete material which replaces the cement concrete, we not only deal can with these industrial by-products, but also reduce the use of cement concrete, further to achieve multiple benefits.
This study aims at activating reductive slag by using alkali-activated technology, adding furnace slag to replace part of reductive slag to reduce the dosage of activating agent, and then conducting experiments related to concrete compressive strength, volume stability and durability using the combination of this cementing material and slag fine aggregates. Finally, we design a production of the alkali-activated reductive slag concrete with 28-day compressive strength of 210 kgf / cm 2, and conduct the feasibility studies.
Study shows that with the furnace slag replacement rate of 50%, alkaline activator 4%(by Na2O), alkali modulus 0.75, replacing natural aggregates with slag fine aggregates, the compressive strength of the mortar can reach normative standards, and its durability is superior to those of cement paste samples. However, its drying shrinkage is much greater than those of cement. As for concrete, the compressive strength of concrete using natural aggregates can reach the 28-day targeted strength, while the compressive strength of concrete with natural aggregates completely replaced with slag fine aggregates doesn’t reach the target, yet is very close to it. Assessing all the experimental results of this study, it is feasible to use slag fine aggregates in the production of alkali-activated reductive slag concrete.
| en_US |