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Cement

About: Cement is a research topic. Over the lifetime, 68440 publications have been published within this topic receiving 829356 citations.


Papers
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Journal ArticleDOI
TL;DR: In this article, the influence of hydroxyethyl cellulose (HEC polymer) and vinyl acetate/ethylene copolymer (EVA) on the pore size distribution was evaluated on pure and polymer-modified cement pastes.

165 citations

Journal ArticleDOI
TL;DR: A 3.5 km (2.2 mi) section of a road in Georgia developed unexpected transverse bumps within 6 months after construction and the source of the bumps appeared to be expansion within the cement-stabilized base course as discussed by the authors.
Abstract: A 3.5-km (2.2 mi) section of a road in Georgia developed unexpected transverse bumps within 6 months after construction. The source of the bumps appeared to be expansion within the cement-stabilized base course. Laboratory examination of samples from areas showing distress revealed the presence of ettringite, a calcium sulfoaluminate the formation of which can be accompanied by severe expansion. This expansive materials was the probable cause of the volume changes causing the transverse bumps. The calcium and alumina needed to form ettringite ware available from the portland cement and the stabilized soil`s clay minerals. The source of the sulfur was identified as the well water that was mixed with the cement-stabilized base. Sulfate attack of cement-stabilized soils is a relatively infrequent problem, but it is highly destructive when it occurs. Currently, there are no firm criteria for identifying when sulfate attack of a cement-stabilized soil is a potential problem nor are there established methods of preventing the attack.

165 citations

Journal ArticleDOI
TL;DR: In this paper, the degradation process of sisal fiber composites was investigated and two matrices were used: one with 50% partial cement replacement by metakaolin (PC-MK) and a reference matrix having as binder only Portland cement (PC).
Abstract: The kinetics of vegetable (sisal) fiber degradation and the mechanisms responsible for deterioration of continuous sisal fiber cement composites are presented in this paper. Two matrices were used: one with 50% partial cement replacement by metakaolin (PC–MK) and a reference matrix having as binder only Portland cement (PC). The durability performance of the composite systems is examined and the mechanisms for the significant delay in the fiber degradation when the total amount of calcium hydroxide is reduced from the matrix discussed. The composites were subjected to 5, 10, 15, 20 and 25 cycles of wetting and drying and then tested under a four point bending load configuration in order to determine the flexural behavior and cracking mechanisms with progressive aging. Furthermore, composites stored under controlled lab conditions were tested under bending load at ages ranging from 28 days to 5 years. Fibers extracted from the aged composites were subjected to thermal analysis, Fourier transform infrared spectroscopy and microscopical observations in order to evaluate the changes in chemical composition and microstructure. Two fiber degradation mechanisms were observed in the PC composites: fiber mineralization due to the precipitation of calcium hydroxide in the fiber cell and surface and degradation of cellulose, hemicellulose and lignin due to the adsorption of calcium and hydroxyl ions. The degradation process occurs rapidly and after 10 cycles of wetting/drying a quite expressive modification in the flexural behavior is observed. The residual mechanical parameters after 25 cycles were the same as those observed in the unreinforced matrix. For the PC–MK composite fiber mineralization was not observed due to the low content of CH in the matrix.

165 citations

Patent
11 Oct 2004
TL;DR: Methods and cement compositions for sealing a underground zone penetrated by a wellbore were provided in this paper, where the cement composition comprises zeolite, cementitious material, and a mixing fluid.
Abstract: Methods and cement compositions are provided for sealing a subterranean zone penetrated by a wellbore, wherein the cement composition comprises zeolite, cementitious material, and a mixing fluid.

165 citations

Journal ArticleDOI
TL;DR: In this paper, both the raw and calcined illite samples, before and after being mixed with Ca(OH) 2 in the presence of simulated cement pore solution, were studied by DTA, TG (for raw illite), XRD, SEM, EMPA and chemical solubility.

165 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20248
20234,852
20228,607
20213,442
20203,929
20194,260