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Full-Text Articles in Engineering
Colloidal Silica: Cement Enhancing Admixture Product Evaluation, Lieska Halsey, David Hansen
Colloidal Silica: Cement Enhancing Admixture Product Evaluation, Lieska Halsey, David Hansen
Nebraska Department of Transportation: Research Reports
As Class F- fly ash (F-ash) becomes scarce, PCC engineers will look to other supplemental cementitious materials (SCM) to replace F-ash and its ASR mitigating properties. Colloidal silica (CS), or nano-silica, has been shown to mitigate ASR at certain replacement levels; however, CS cannot be a full replacement of F-ash. Engineers at the Nebraska Department of Transportation (NDOT) learned of CS from a presentation given by Intelligent Concrete, Inc. at the 2019 Nebraska Concrete Professionals Association Conference and decided to investigate the potential use of CS in NDOT concrete mix designs.
Application Of Internal Curing To Improve Concrete Bridge Deck Performance, Arman Abdigaliyev, Yong-Rak Kim, Jiong Hu
Application Of Internal Curing To Improve Concrete Bridge Deck Performance, Arman Abdigaliyev, Yong-Rak Kim, Jiong Hu
Nebraska Department of Transportation: Research Reports
Due to the relatively high cement content and low water-to-cement ratio (w/c) used, bridge deck concrete is prone to premature cracking. Internal curing has been found to greatly reduce the chance of premature cracking as well as concrete deterioration. This research project was intended to develop internally cured bridge deck concrete based on a local mix design in Nebraska. Four different lightweight fine aggregate (LWFA) as internal curing agents were evaluated, and their effects on fresh, mechanical, durability, and shrinkage properties of concrete were studied. To identify the most effective LWFA dosage for shrinkage reduction, different replacement rates of sand …
Evaluation Of Reducing Cement Content In Ndor Class R Combined Aggregate Gradations, Miras Mamirov, Jiong Hu, Yong-Rak Kim
Evaluation Of Reducing Cement Content In Ndor Class R Combined Aggregate Gradations, Miras Mamirov, Jiong Hu, Yong-Rak Kim
Nebraska Department of Transportation: Research Reports
The main objective of this research project was to achieve a cement reduction on Nebraska slip-form pavement concrete through aggregate particle packing optimization. A literature review was conducted to examine different aggregate optimization tools, quality control tests, and historical data of Nebraska Department of Transportation (NDOT) pavement mixtures. It was found that the Modified Toufar Model has good potential in optimizing particle packing and predicting packing degrees. The combined aggregate void content test was found to be useful to experimentally justify optimized aggregate gradations. The Box Test with a modified index and image analysis tool for surface void estimation was …