Shen Rongjian, Li Xiaojun, Li Shen
Shanxi Anjian Investment and Construction Co., Ltd., Xi'an 710003, China.
College of Safety science and Engineering, Xian University of Science and Technology, Xi'an 710054, China.
Materials (Basel). 2025 Jul 9;18(14):3240. doi: 10.3390/ma18143240.
Coal gasification slag (CGS) is a solid byproduct generated during coal gasification. Stacking and land-filling of CGS wastes substantial land resources and has significant environmental risks. In this paper, based on the Ca/Si and Si/Al ratios of the raw materials, the mix design of alkali-activated CGS concrete was optimized using a pure center-of-gravity design method. The compressive and flexural strengths of geopolymer concrete with varying mix proportions were measured to investigate the effects of sodium silicate modulus, material content, and dry density on its mechanical properties. Specimens of different sizes were prepared to analyze the influence of testing methods on the compressive, flexural, and tensile properties. The results indicate that the mechanical properties of geopolymer concrete are significantly influenced by the raw material composition and the modulus of the activator. With increasing curing age, both compressive and flexural strengths exhibit varying degrees of improvement. The stress-strain behavior of alkali-activated CGS concrete aligns closely with that of ordinary concrete. A comparative analysis of 100 mm length and 20 mm length cubic specimens revealed a compressive strength size conversion coefficient of approximately 0.456, while the flexural specimen exhibited a coefficient of 0.599. For tensile strength evaluation, both the Brazilian splitting method and the double punch test method yielded consistent and reliable results, demonstrating their suitability for assessing CGS-based concrete.
煤气化炉渣（CGS）是煤气化过程中产生的固体副产品。CGS的堆放和填埋占用了大量土地资源，且存在重大环境风险。本文基于原材料的Ca/Si和Si/Al比值，采用纯重心设计方法优化了碱激发CGS混凝土的配合比设计。测定了不同配合比的地聚合物混凝土的抗压强度和抗折强度，以研究硅酸钠模量、材料用量和干密度对其力学性能的影响。制备了不同尺寸的试件，分析试验方法对抗压、抗折和抗拉性能的影响。结果表明，地聚合物混凝土的力学性能受原材料组成和激发剂模量的显著影响。随着养护龄期的增加，抗压强度和抗折强度均有不同程度的提高。碱激发CGS混凝土的应力-应变行为与普通混凝土密切相关。对100mm边长和20mm边长的立方体试件进行对比分析，得出抗压强度尺寸换算系数约为0.456，抗折试件的系数为0.599。对于抗拉强度评估，巴西劈裂法和双冲试验法均得出一致可靠的结果，表明它们适用于评估基于CGS的混凝土。
