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Chemical Shrinkage Analysis of Nano Silica Cementitious Binders

Project ID: 4967
Principal Investigator: Katie Bartojay P.E.
Research Topic: Improving Geotechnical Infrastructure Reliability
Funded Fiscal Years: 2013
Keywords: concrete, cement, cement reduction, cementitious, green cement, nano-silica, shrinkage, sustainability

Research Question

Can nano-scale silica particles optimize the hydrated cementitious matrix of concrete, thereby increasing concrete strength and durability while making the concrete more sustainable (green)? Do size effects of the nano-silica particles relate to a change in chemical shrinkage and overall performance of concrete?

Need and Benefit

Roughly 5 to 10 percent of global CO2 emissions are related to the manufacture and transportation of cement, a major ingredient of concrete. In 2011 about 68 million tons of Portland cement was produced in the US and 3.4 billion tons worldwide. Concrete is a key building material in Reclamation structures. It is important that we find materials that can reduce the total cementitious materials needed to create more sustainable "green" structures which provide equal or better performance and extend the service life of our structures.

Jon Belkowitz , a Ph D student from Stevens Institute of Technology has already performed research experiments to discern how the size of nano silica effect residual water and chemical shrinkage in the cured cement composite. Excess water in the cement composite has the potential to cause chemical degradation of the cement composite over time. His current testing has included testing on a macro scale for concrete strength and shrinkage, and thermal gravimetric analysis to identify the amount of residual water in the cement composite at later ages. The Department of Defense has agreed to partner with Jon to run Nulcear Magnetic Resonance (NMR) testing at the micro scale this fall. The chemical shrinkage testing to be performed by this research will be at the cement paste level to tie the macro and micro level analysis together.

By partnering with the Stevens Institute of Technology we can together answer the questions of whether or not nano-scale silica particles optimize the hydrated cementitious matrix of concrete, thereby increasing concrete strength and durability while making the concrete more sustainable and, if size effects of the nano-silica particles relate to a change in chemical shrinkage and overall performance of concrete.

Contributing Partners

None

Research Products

Bureau of Reclamation Review

The following documents were reviewed by experts in fields relating to this project's study and findings. The results were determined to be achieved using valid means.

Preliminary Chemical Shrinkage Analysis of Nano Silica Cementitious Binders (interim, PDF, 713KB)
By Mr. John Bret Robertson
Report completed on September 30, 2013

The investigation was performed by personnel of the Materials Engineering and Research Laboratory (MERL). ASTM C 1608 Method A, "Standard Test Method for Chemical Shrinkage of Hydraulic Cement Paste " was used to compare various cementitious binders according to the test matrix developed. Approximately 50 samples were tested. Results are present in this report.
Keywords: nano-silica, cement

This information was last updated on October 20, 2014
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