EFFECT OF FREEZE-THAW CYCLING ON THE MECHANICAL PROPERTIES OF FIBER-REINFORCED CEMENTED SOIL
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摘要: 冻融循环作用是影响纤维水泥土微观结构和强度的主要因素。通过一系列无侧限抗压强度试验和冻融循环试验,研究养护时间、纤维长度及冻融循环次数对玄武岩纤维水泥土无侧限抗压强度的影响。研究结果表明:纤维水泥土的强度随着龄期的增加而增大;加入纤维的水泥土强度有所增加;随着冻融循环次数的增加,水泥土表面开始产生裂纹,没有添加纤维的水泥土在经过3次冻融循环后表面出现裂纹,经过6次冻融循环后,裂纹贯通并碎裂,而添加纤维的水泥土在经过6次冻融循环后,表面才出现裂纹。随着冻融循环次数的增加,纤维水泥土的强度有所下降,没有添加纤维的水泥土强度下降最快,与冻融循环次数呈线性关系降低。随着冻融循环次数的增加,纤维长度对水泥土无侧限抗压强度的影响越来越小。纤维的加入可以有效地提高水泥土的强度,随着冻融循环次数的增加,纤维水泥土的强度会降低,冻融循环作用对水泥土的强度有很重要的影响。纤维的加入可以有效地降低强度损失率,较好地提高水泥土的抗冻性。Abstract: Freeze-thaw cycling is one of the main factors influencing the micro-structure and strength of fiber-reinforced cemented soil. A series of unconfined compression tests and freeze-thaw tests were conducted on basalt fiber-reinforced cemented clay specimens to investigate the effects of the number of freeze-thaw cycles, the curing time and the fiber length. The results showed that the strength of cemented soil continued to increase with increasing curing time. The strength of cemented soil was improved when the fiber was added. As the number of freeze-thaw cycles increased, cracks began to appear on the surface of the cemented soil. Obvious cracks appeared on the surface of the cemented soil without fiber after being subjected to 3 freeze-thaw cycles. Then, penetrating cracks appeared in the cemented soil without fiber, and the cemented soil completely lost its bearing capacity after being subjected to 6 freeze-thaw cycles; in contrast, cracks began to appear on the surface of cemented soil with fiber after being subjected to 6 cycles. As the number of freeze-thaw cycles increased, the strength of the fiber-reinforced cemented soil tended to decrease. The strength of cemented soil without fiber decreased the most. The relationship between the strength and the number of freeze-thaw cycles was linear. With the increase of the number of freeze-thaw cycles, the fiber length had less and less influence on the strength. The research indicated that the strength of cemented soil could be effectively improved when fiber was added. Although the strength of a fiber-reinforced cemented soil decreased as the number of freeze-thaw cycles increased, the strength loss decreased, and the frost resistance of a cemented soil was improved when the basalt fiber was added.
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Key words:
- cemented soil /
- basalt fiber /
- freeze-thaw cycling /
- unconfined compressive strength
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