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Landfill is the most commonly used method for disposal of waste materials since it is one of the least expensive methods. In order to dispose of any hazardous material to a landfill, a liner is used, which protects the underlying land and groundwater since it acts as a barrier to fluid movement. Of the various methods available for providing improved and more effective properties of landfills, methods involving the use of bentonite, cement, lime, gypsum, etc., have been explored in the laboratory. The aim is to overcome the problem and deficiencies of the existing liners. It is observed from the experimental results that the metal concentrations of the input waste solution can be reduced to 80–98% using a soil‐cement admixture, 60–95% using a soil‐gypsum mixture, 45–95% using a soil‐bentonite mixture, 50–90% for soil, 35–80% using a soil‐lime mixture, as liner materials. The permeation rate of different metals through the different soil‐admixture media depends on various factors. A simple mathematical treatment of the phenomenon related to the permeation of liquid through the admixture of the clay and other components has been developed. The experimental results show satisfactory agreement with the predictions. 相似文献
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The purpose of this research is to demonstrate the possibility of applying one geophysical method to studying untraditional systems as is the case with Portland-cement-based materials. The research demonstrates how conventional paleomagnetic methodology can be employed in studying the mode of magnetic recording in present-day industrial materials. Portland-cement admixtures such as fly ashes and furnace slags should be discriminated, because those particles interact in soils and sediments in nature. Moreover, a better undertanding of magnetic remanent acquisition in model materials can serve to improve the interpretation of magnetic remanent acquisition in natural rocks formed a long time ago. The magnetic constituents of Portland-cement paste and mortar acquire a magnetic remanence due to their alignment with the earth's magnetic field at the casting place. This magnetization can be measured using ordinary paleomagnetic techniques. The alignment of the individual magnetic particles accounts for the intensity of the magnetic remanence, which can be increased by adding water and by vibration before setting and hardening. Blast furnace slag admixtures also add to the enhancement of the intensity of remanence. The magnetization of Portland-cement-based materials shows a near linear relationship with the water /cement (w/c) ratios employed in the experimental work; the w/c ratios range between 0.2 – 0.6 in pastes and 0.3 – 0.6 in mortar. Stable remanent magnetization was obtained during the first seven days of setting and hardening, a period necessary for magnetic particles to become locked parallel to the earth's magnetic field. The stability of magnetic remanence predicts the usefulness of the methodology in studying the properties of Portland cement and particularly in the control of iron-bearing admixtures. 相似文献
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预应力管道压浆浆液外加剂种类及配合比的选取是管道压浆工艺的重要部分。为研究减水剂和矿物掺和料对管道压浆浆液的影响及作用机理,进而研制一种流动性、保水性及力学性能优异的管道压浆浆液,本研究采用单组分掺和试验的方法,对掺有减水剂与矿物掺合料两种不同压浆浆料进行流动性、压力泌水率、沉积密度比、抗压及抗折性能试验研究,并得到不同掺量外加剂对压浆浆液和易性与力学性能的影响和作用机理,以及合适的外加剂掺量配比。研究表明：聚羧酸减水剂30 min与60 min流动度最佳,且压力泌水率表现也较为良好,综合考虑聚羧酸减水剂为压浆浆液的优良减水剂;聚羧酸减水剂掺量在0.4%～0.5%时,浆液的流动性与保水性表现良好,随掺量的继续增加,流动性提升较小;微珠由于其物理性质以及化学性质,对提高压浆浆液和易性与力学性能的效果较为明显;微珠掺量在10%～15%时,压浆浆液的和易性达到临界状态。 相似文献
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钢筋混凝土耐久性海洋暴露试验 总被引：4，自引：0，他引：4
对不同技术条件的钢筋混凝土试件进行长期的海洋暴露腐蚀试验,以了解其服役特性,为钢筋混凝土结构的耐久性设计提供依据。近7年的暴露结果表明：在混凝土中掺加高炉矿渣等活性掺合料,能大大降低氯离子渗透速率,提高钢筋混凝土的耐久性。 相似文献
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