Many geotechnical structures,such as the subgrade of high-speed railway,are extremely sensitive to micro deformations.As one of the most commonly used indexes in China to evaluate the potential swelling level of expan...Many geotechnical structures,such as the subgrade of high-speed railway,are extremely sensitive to micro deformations.As one of the most commonly used indexes in China to evaluate the potential swelling level of expansive soils,the effectiveness and accuracy of free swelling ratio should be highly required.However,due to the deficiency of geotechnical test regulations for the free swelling ratio test,non-negligible variation difference is often observed among the test results of the same type of soil samples.Thus,a series of laboratory tests are conducted to figure out the influences of soil particle size,initial soil temperature,and wet-dry circulation on the free swelling ratio of expansive soils.The results show that the initial soil temperature exerts an obvious influence on free swelling ratio and a relative weak influence on soil mass of expansive soil with the micro soil particle size(d<0.075 mm),and the correlation becomes unclear when soil particle size is within the range of 0.075 mm≤d<0.500 mm.A larger particle size of expansive soils induces a larger free swelling ratio and soil mass in the soil measuring cup regardless of initial soil temperature.However,the enlarging amplitude decreases as the particle size of expansive soils increases.There is a progressive enlargement of free swelling ratio at the first two wet-dry cycles and then it attenuates gradually when the number of wetdry cycles further increases.展开更多
The physical and chemical properties and soundness of Baosteel Power Plant＇ s dry desulphurized fly ash were systematically investigated and compared with those of the similar byproducts produced by some other domest...The physical and chemical properties and soundness of Baosteel Power Plant＇ s dry desulphurized fly ash were systematically investigated and compared with those of the similar byproducts produced by some other domestic power plants. The feasibility of these byproducts used as a construction material was also analyzed. The results show that Baosteel＇s dry desulphurized fly ash is a kind of ash with high calcium and high sulfur contents, which has the characteristics of volcanic ash activity. It contains sulfate and sulfite, and is easy to cause sulfate activation. It has higher activity compared with common fly ash. But higher calcium sulfite and free-CaO contents in ash will bring about soundness concerns to users. Therefore, quality tests and volume control will be necessary when fly ash is used as a construction material.展开更多
基金Project(2016M591957) supported by the China Postdoctoral Science FoundationProjects(51878667,51678571)supported by the National Natural Science Foundation of ChinaProject(2017XKQY050) supported by the Fundamental Research Funds for the Central Universities,China。
文摘Many geotechnical structures,such as the subgrade of high-speed railway,are extremely sensitive to micro deformations.As one of the most commonly used indexes in China to evaluate the potential swelling level of expansive soils,the effectiveness and accuracy of free swelling ratio should be highly required.However,due to the deficiency of geotechnical test regulations for the free swelling ratio test,non-negligible variation difference is often observed among the test results of the same type of soil samples.Thus,a series of laboratory tests are conducted to figure out the influences of soil particle size,initial soil temperature,and wet-dry circulation on the free swelling ratio of expansive soils.The results show that the initial soil temperature exerts an obvious influence on free swelling ratio and a relative weak influence on soil mass of expansive soil with the micro soil particle size(d<0.075 mm),and the correlation becomes unclear when soil particle size is within the range of 0.075 mm≤d<0.500 mm.A larger particle size of expansive soils induces a larger free swelling ratio and soil mass in the soil measuring cup regardless of initial soil temperature.However,the enlarging amplitude decreases as the particle size of expansive soils increases.There is a progressive enlargement of free swelling ratio at the first two wet-dry cycles and then it attenuates gradually when the number of wetdry cycles further increases.
文摘The physical and chemical properties and soundness of Baosteel Power Plant＇ s dry desulphurized fly ash were systematically investigated and compared with those of the similar byproducts produced by some other domestic power plants. The feasibility of these byproducts used as a construction material was also analyzed. The results show that Baosteel＇s dry desulphurized fly ash is a kind of ash with high calcium and high sulfur contents, which has the characteristics of volcanic ash activity. It contains sulfate and sulfite, and is easy to cause sulfate activation. It has higher activity compared with common fly ash. But higher calcium sulfite and free-CaO contents in ash will bring about soundness concerns to users. Therefore, quality tests and volume control will be necessary when fly ash is used as a construction material.
