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粉土因具有黏聚力低、水稳性差的特点,在工程中的使用受限;玉米秸秆具有较高的抗拉强度,是一种性能良好、环保的天然纤维,将经过防腐处理后的玉米秸秆作为加筋材料纤维掺加到粉土中,是否会起到良好的加固效果,本文将就此展开研究。首先对玉米秸秆皮进行抗拉强度测试,选取抗拉强度较高的无茎节点秸秆皮作为试样;将该试样用卡松、双乙酸钠、聚乙烯醇3种防腐溶液进行浸泡,并对浸泡处理后的试样进行抗拉强度测试,结果表明浸泡过3种防腐剂的秸秆在浸泡水后抗拉强度均比天然秸秆有不同程度的提升,其中聚乙烯醇的防腐效果最好,浸泡12周后抗拉强度比天然秸秆高出约60%;对用聚乙烯醇浸泡后的试样进行显微镜拍照和称重测试,显示秸秆在浸泡3天后对聚乙烯醇的吸收达到饱和。将用聚乙烯醇防腐处理后的玉米秸秆纤维掺加到粉土中,制样进行三轴试验,发现玉米秸秆加筋对粉土强度的提高主要体现在黏聚力上,其增幅为素土试样的100%,改善了土体的水稳定性;其应力-应变曲线更倾向于应变-硬化,有别于素土的应变软化,破坏形态较为完整,有别于素土的斜截面破坏,这说明粉土加入玉米秸秆纤维后抵抗外界荷载的能力增强。
Due to its low cohesion and poor water stability, silt has limited use in engineering. Corn stalk has high tensile strength and is a kind of natural fiber with good performance and environmental protection. After being treated with preservative Whether corn stalks are added as reinforcing material fibers into silt will play a good reinforcing effect. This article will start a study on this. Firstly, the tensile strength of corn stalks was tested, and the stalks without stalk with higher tensile strength were selected as the samples. The samples were soaked with three kinds of preservative solution of cassia, sodium diacetate and polyvinyl alcohol Tensile strength of the samples after immersion treatment showed that the three kinds of preservative soaked in straw after immersion in water than the tensile strength of natural straw have different degrees of improvement, of which the best preservation effect of polyvinyl alcohol, After 12 weeks of soaking, the tensile strength was about 60% higher than that of natural straw. Microscopic pictures and weighing tests of the samples soaking with polyvinyl alcohol showed that the straw saturated the polyvinyl alcohol after 3 days soaking. The corn stalk fiber treated with polyvinyl alcohol was blended into the silt soil to make the sample for triaxial test. It was found that the increase of the corn stalk reinforcement on the silt strength was mainly reflected in the cohesion force, 100% of the sample improves the water stability of the soil; the stress-strain curve is more strain-hardening than strain-softening of the native soil, and the damage morphology is more complete than that of the plain soil , Which indicates that the ability of silt to resist the external load after adding corn stalk fiber is enhanced.