水泥改性黄金尾矿渣及其在道路底基层中的性能

孙星辰，王琨^*，李强飞，谢丹丹，姜自玉

山东交通学院交通土建工程学院，山东 济南  250357

摘要：为评估黄金尾矿渣规模化应用于道路底基层的可行性，将水泥掺入黄金尾矿渣制备水泥改性黄金尾矿渣试件，水泥的质量分数w分别为0、3%、5%、7%，对水泥改性黄金尾矿渣试件分别进行直剪试验、固结试验、加州承载比（California bearing ration，CBR）试验、冻融循环试验，评估黄金尾矿渣作为道路底基层材料的可行性。结果表明：1）水泥改性黄金尾矿渣试件的正应力与抗剪强度均呈线性关系；w相同时，水泥改性黄金尾矿渣试件的抗剪强度随正应力的增大而线性增大；正应力相同时，水泥改性黄金尾矿渣试件的抗剪强度随w的增大先增大后减小；w=5%时，水泥改性黄金尾矿渣试件的抗剪强度最大。2）w相同时，水泥改性黄金尾矿渣试件的形变随固结时间的增加而缓慢增大；固结时间相同时，水泥改性黄金尾矿渣试件的形变随w的增大先减小后增大，w=5%时，水泥改性黄金尾矿渣试件的形变最小。3）压实度相同时，水泥改性黄金尾矿渣试件的加州承载比随w的增大先增大后减小；w相同时，水泥改性黄金尾矿渣试件的加州承载比随压实度的增大而增大；w=5%、压实度为95%时，加州承载比最大。4）冻融循环试验中，水泥改性黄金尾矿渣试件的抗压强度和抗拉强度均随w的增大先增大后减小；在硫酸盐冻融条件下，未掺加水泥的黄金尾矿渣试件、w=5%的水泥改性黄金尾矿渣试件的抗压强度均随冻融循环次数的增大而减小，后者降幅明显减小；增大硫酸盐质量分数会加剧水泥改性黄金尾矿渣试件的受侵蚀程度，降低水泥改性黄金尾矿渣试件的抗压强度。w=5%时，水泥改性黄金尾矿渣可显著提高抗压强度、抗拉强度、抗变形和耐久性方面的性能，满足其在道路底基层的技术要求。

关键词：黄金尾矿渣；底基层；直剪试验；固结试验；CBR试验；水泥

Cement-modified gold tailings and its performance in the base layer of road

SUN Xingchen, WANG Kun^*, LI Qiangfei, XIE Dandan, JIANG Ziyu

School of Civil Engineering, Shandong Jiaotong University, Jinan 250357, China

Abstract: To assess the feasibility of using gold tailings on a large scale as a subbase material for road subgrades, cement is mixed with gold tailings at different mass ratios w (0%, 3%, 5%, 7%) to prepare specimens of gold tailings. The specimens undergo direct shear tests, consolidation tests, California bearing ratio (CBR) tests, and freeze-thaw cycling tests to evaluate the feasibility of gold tailings as a base material for roads. The results indicate: 1) The normal stress and shear strength of cement-modified gold tailings samples are linearly related. At the same w, the shear strength of the cement-modified gold tailings specimens increases linearly with the increase of normal stress; under the same normal stress, the shear strength of the cement-modified gold tailings specimens initially increases and then decreases with the increase ofw; the specimen with w=5% exhibits the highest shear strength. 2) At the same w, the deformation of the cement-modified gold tailings specimens gradually increases with the extension of consolidation time; with the same consolidation time, the deformation of the cement-modified gold tailings specimens initially decreases and then increases with the increase of w. The deformation of the specimen made with w=5% cement-modified gold tailings is the smallest. 3) At the same compaction degree, the California bearing ratio of the cement-modified gold tailings specimens increases initially and then decreases with the increase of w; at the same w, the California bearing ratio of the cement-modified gold tailings specimens increases with the increase of compaction degree; the maximum California bearing ratio is observed at w=5% and a compaction degree of 95%. 4) In the freezing and thawing test, the compressive strength and tensile strength of cement-modified gold tailings specimens first increase and then decrease with the increase of w; under sulfate freeze-thaw conditions, the compressive strength of gold tailings specimens without cement addition and those with 5% cement-modified gold tailings decreases with the increase of freeze-thaw cycle times, while the latter shows a significantly reduced decline; increasing the sulfate mass fraction exacerbated the erosion of the cement-modified gold tailings specimens, reducing their compressive strength. The cement-modified gold tailings with w=5% can significantly improve compressive strength, tensile strength, deformation resistance, and durability, meeting the technical requirements for use as road base materials.

Keywords: gold tailings; subbase; direct shear test; consolidation test; CBR test; cement