Characteristics, strength development and microstructure of cement mortar containing oil-contaminated sand
Characteristics, strength development and microstructure of cement mortar containing oil-contaminated sand
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DOI：
10.1016/j.conbuildmat.2020.119155
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发表时间：
2020-08-20
影响因子：
7.4
通讯作者：
Al-Jabri, Khalifa Saif
中科院分区：
文献类型：
--
作者：
Abousnina, Rajab;Manalo, Allan;Al-Jabri, Khalifa Saif
在混凝土中应用油污染砂（OCS）被认为是一种高度可持续的解决方案和具有成本效益的回收方法，可以最大限度地减少其对环境的负面影响。本文研究了含油砂的水泥砂浆的力学特性、强度发展、水化和微观结构。在本研究中调查的参数是石油污染的水平，混合方法，水灰比（W/C），和固化的年龄。研究了含油砂水泥砂浆365 d硬化试样的微观结构特征、物理力学性能和强度发展规律。结果表明，与未污染的样品相比，原油的存在高达4%可以改善砂浆的性能。水灰比为0.5时抗压强度最佳。掺2%轻质原油的污染砂水泥基砂浆一年后强度与未掺污染砂的水泥基砂浆相当。然而，发现具有高水平轻质原油污染（4-10%）的水泥砂浆的强度增加速率缓慢。砂浆含有污染的细砂高达2%的油的微观结构似乎是相当致密的，并具有更细的孔结构。界面张力区（ITZ）不受高达2%的原油的影响，然而，较高百分比的油污染物（6-10%）会增加孔隙度并影响ITZ。(C)2020爱思唯尔有限公司保留所有权利。
The application of oil-contaminated sand (OCS) in concrete is considered a highly sustainable solution and cost-effective recycling method for minimising its negative effect to the environment. The present study investigated the mechanical characteristics, strength development, hydration and microstructure of cement mortar containing oil-contaminated sand. The parameters investigated in the present study are the level of oil contamination, mixing method, water-to-cement (w/c) ratio, and the age of curing. The microstructural characteristics of hardened samples, physical and mechanical properties and the strength development pattern of cement mortar containing oil-contaminated sand were assessed up to 365 days. Result shows that the presence of crude oil up to 4% can improve the properties of mortar compare to the uncontaminated samples. The mixing of water and cement before adding oil-contaminated sand is found effective method of mixing, while the optimum compressive strength obtained at a w/c ratio of 0.5. The strength of cement-based mortar having contaminated sand with 2% light crude-oil is similar to the cement mortar with uncontaminated sand after one year. However, the rate of gaining strength of cement mortar with high levels of contamination with light crude oil (4-10%) is found slow. The microstructure of mortar containing contaminated fine sand up to 2% oil appeared to be quite dense and have a finer pore structure. The interfacial tension zone (ITZ) is not affected by crude oil up to 2%, however, the higher percentages of oil contamination (6-10%) can increase the porosity and affect the ITZ. (C) 2020 Elsevier Ltd. All rights reserved.