Modification of Low‐Density Slag Cementing Slurry with SiC Whiskers at High Temperature

Abstract

The aim of this study was to improve the mechanical properties of a slag solidified body at high temperatures. Composite materials with different contents of SiC whiskers were prepared and characterized using techniques such as mechanical testing, scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FT-IR). When the SiC whisker addition is 1% mass percentage, the compressive and tensile strength of the slag solidified body after hydration for 7 days increased by 10.2% and 39.3%, respectively, and Young’s modulus decreased by 16.8%. The results show that the addition of SiC whiskers can enhance the mechanical properties of solidified slag bodies at high temperatures. According to the test results, the hydration products of the slag solidified body mainly consist of honeycomb tobermorite (C-S-H) gel at high temperatures in addition to a small number of spherical products. The spheres are connected to form a dense structure; however, noticeable cracks were present. The addition of SiC whiskers effectively inhibited the initiation and further development of microcracks and improved the bearing capacity of the slag solidified body.

Strength development and hydration products of alkali-activated Pisha sandstone geopolymer cement

“…The cylindrical samples were formed by pressure (50 kN), with a size of Φ50 mm × 50 mm. After removal from the mold, 15 samples of each formulation were covered with a plastic bag (preventing evaporation) and cured in an 80 °C (Fu et al, 2021;Luo et al, 2022;Snellings et al, 2022;Wu et al, 2022) air box for 12 h. The samples were then set at room temperature and further solidified and hardened at 20 °C for 1, 3, 7, 28, and 90 days. In the last step, the compressive strength of the three samples of each formulation was measured at 1, 3, 7, 28, and 90 days.…”