Effect of steel slag powder on the performance of controlled low-strength materials mixed with recycled aggregates
- Vol.53(6), Dec
- USA Springer 2023
- 1338-1346p.
Steel slag powder and construction waste have received widespread attention for their resource utilization as solid waste. This article uses steel slag powder and recycled concrete aggregates to prepare controlled low-strength materials (CLSM). The study investigates the influence of steel slag powder replacing cement and recycled aggregates on the workability and hardening performance of CLSM. At the same time, the microstructure of CLSM was analyzed. The experimental results show that increasing the content of recycled aggregate can effectively reduce the bleeding rate of CLSM while ensuring its working performance, which is beneficial for the flowability of CLSM. As the content of recycled aggregate increases, the compressive strength of CLSM gradually decreases, and the greater the content of recycled aggregate, the faster the strength decreases. When the steel slag dosage is 15%, the addition of steel slag powder can slightly reduce the 28-day compressive strength of CLSM, but the reduction rate is small. However, when the dosage of steel slag powder exceeds 15%, the compressive strength of CLSM begins to show a clear downward trend. The impact of steel slag powder content on the strength of CLSM should be particularly emphasized, and a reasonable dosage (e.g., 15%) can achieve similar strength to that of pure cement. Microscopic analysis shows that with excessive steel slag powder content, the hydration products in CLSM decrease. SEM images reveal that recycled aggregates contain a large number of voids inside due to crushing, which leads to a continuous decrease in the strength of CLSM as the content of recycled aggregates increases.