دانلود رایگان مقاله انگلیسی رفتار مکانیکی و ریزساختاری رس دریایی تثبیت سیمانی شده با یک عامل متاکائولین به همراه ترجمه فارسی
|عنوان فارسی مقاله:||رفتار مکانیکی و ریزساختاری رس دریایی تثبیت سیمانی شده با یک عامل متاکائولین|
|عنوان انگلیسی مقاله:||Mechanical behaviour and micro-structure of cement-stabilised marine clay with a metakaolin agent|
|رشته های مرتبط:||مهندسی عمران، خاک و پی، سازه و سازه های دریایی|
|فرمت مقالات رایگان||مقالات انگلیسی و ترجمه های فارسی رایگان با فرمت PDF میباشند|
|کیفیت ترجمه||کیفیت ترجمه این مقاله متوسط میباشد|
|نشریه||الزویر – Elsevier|
مقاله انگلیسی رایگان
|دانلود رایگان مقاله انگلیسی|
ترجمه فارسی رایگان
|دانلود رایگان ترجمه مقاله|
|جستجوی ترجمه مقالات||جستجوی ترجمه مقالات مهندسی عمران|
بخشی از ترجمه فارسی مقاله:
۲٫ مواد و روش های انجام آزمایش
۲-۲- آماده سازی نمونه ها و آزمایش فشاری محدود نشده
بخشی از مقاله انگلیسی:
Metakaolin, a fine powder material, has been widely used as an effective additive to produce the highperformance concrete since 1990s, for its high efficiency and relatively low price. However, metakaolin has rarely been attempted in admixtures of cement-stabilised soft clays until presently. This paper focuses on the macro-strength and micro-structure development of cement-stabilized Lianyungang marine clay mixed with metakaolin. The results show that the unconfined compression strengths of cemented soils containing 3% and 5% MK are approximately 2.0–۳٫۰ times of that of materials without MK, that is MK can effectively improve the quality of cemented soils. Additionally, the strength with MK after 7 day’s curing periods is approximately 0.87 times of that after 28 day’s, while this ratio is 0.58 for the soils lacking MK, which indicates that the cemented soils containing MK show sufficient earlier strength than those lacking MK. Finally, the microstructure analysis reveals that MK mainly changes the pore volume distribution, which ranges between 0.01 lm and 1 lm, and produces more CSH/Aft/ CASH bonding and fissures due to the secondary hydration and pozzolanic reactions.
۲٫ Materials and testing methods
Lianyungang clay, a type of quaternary marine sedimentation, is widely deposited in the eastern coastal areas of China, which is of the high water content, high sensitivity, and high compression while of low strength and low permeability. The basic properties of the selected soil samples are listed in Table 1 and it is characterized as a high plasticity (CH) clay by the USCS (Unified Soils Classification System , ASTM D2487-11). The mineral component of the Lianyungang marine clay is listed in Table 2, where the samples were pre-treated by ethylene glycol and the semi-quantitative analysis was carried out by the Jade software. Note that the clay mineral is the main component and the content of the interstratified illite/smectite is over 40%. Table 3 presents the oxides of the ordinary Portland cement (OPC 42.5 R/N) and metakaolin (Metamax from BASF German). Note that the Portland cement used in this study falls well within the guidelines of the European Cement Standard (EN 197-1), which specifies that the ratio of CaO to SiO2 should exceed 2.0 and the MgO content should not exceed 2.0%. The total content of SiO2 and Al2O3 in the MK was approximately 92%, the average particle size was less than 4 lm and the specific surface area was approximately 10 m2 /g.
۲٫۲٫ Sample preparation and unconfined compression test
To prepare the testing samples, the selected marine clay was first dried at 30 C, and distilled water was then added until the water content arrived at 70% (approximately 1.2 wL, between the sample’s natural water content, i.e. 61.5% and the maximum natural water content of the site, i.e. 75%). After one day of curing, the OPC (mass content of cement to wet soil at 12% and 15%) and MK (mass content of MK to wet soil at 0%, 1%, 3% and 5%) were mixed with the prepared soils. Note that the selected cement content was less than that adopted in most ground improvement projects in Chinese highway engineering (usually ranging from 15% to 20%)  considering the effectiveness and economy of MK agent, while the MK content covered the ranges applied in concrete engineering (usually the ratio of cement mass to the total mass of the cement and MK ranges from 8% to 20% ). The mixed clay-cement-MK paste was then agitated for 5–۱۰ min and transferred into a plastic mould with detachable covers at both ends, which was of 100 mm in length and 50 mm in diameter. To improve the uniformity and reliability, the soil paste was artificially compacted by vibration, and more than three parallel samples were fabricated for each group to avoid discrete results. The density and moisture content of samples of the soil-cement-MK paste after compaction were measured instantly and listed in Table 4, where the water content decreased with cement and MK content because these above two materials increased the solid mass. After the first 24 h of curing, the cemented soil samples were removed from the moulds, wrapped in polythene bags and stored in a standard chamber at 95% humidity and 20 ± ۲ C. Note that this sample preparation procedure is widely recommended for the cemented soft clay [25,13,14,19]. After 7 and 28 days of curing, the samples were removed to perform the uncon- fined compression test (i.e., UCT) to determine their strength (fcu) and secant modulus (E50). The shearing rate was defined at 1 mm/min in this study.