Civil Engineering ETDs

Publication Date

Fall 11-15-2019

Abstract

Calcium Silicate Hydrate (C-S-H) acts as the primary binding material that is mainly responsible for the strength and durability of concrete. C-S-H constitutes approximately 67% of hydrated ordinary Portland cement by volume. C-S-H forms with a range of stoichiometric formula dependent on many factors such as CaO/SiO2 ratio. The continued rise of hydrocarbon exploration in the United States has developed the need for improved wellbore cementing materials. Binders with good bond strength to steel and rock interfaces, low shrinkage, and high cracking strength are sought by the oil and gas industry. The incorporation polymers and nano materials has evolved into a new generation of C-S-H characterization. Emerging technologies continue to require the use of materials with enhanced mechanical properties. The intent of this thesis is to synthesize and analyze the effect of incorporating carboxylated styrene-butadiene rubber (XSBR), SBR, and XSBR modified with nano materials ranging from 0.25%-1.0%, by weight of nanoparticles to binder, on the physical, mechanical and chemical characteristics of C-S-H. In this work, C-S-H was synthesized by calcining calcium carbonate and combining the lime, silica and deionized water. XSBR was initially added at levels ranging from 0%-15% to characterize the effect of incorporating a range of XSBR to isolate the optimal polymer content. The desired properties then led to the comparison of SBR with XSBR, comparing the property changes with the addition of the carboxyl group. Finally, the dispersing of nanomaterials in XSBR were incorporated into the C-S-H slurry at the initial mixing stage. Physical, mechanical, chemical, and microstructural investigations enabled us to identify the materials-property relationships showing a reduction in elastic modulus, reactant products, and an increase in strain at failure, ultimate strength, and water content of C-S-H. We show the possible use of polymer-modified C-S-H with improved material properties applicable to the oil and gas industry.

Keywords

Calcium-Silicate-Hydrate, Styrene-butadiene Rubber, Mechanical, Chemical

Sponsors

Sandia National Laboratory

Document Type

Thesis

Language

English

Degree Name

Civil Engineering

Level of Degree

Masters

Department Name

Civil Engineering

First Committee Member (Chair)

Mahmoud Reda Taha

Second Committee Member

John Stormont

Third Committee Member

Edward Matteo

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