Extra! Extra! Read all about it!

Check out my article in Engineering Structures Volume 252 from February 2022 titled Hybrid fiber reinforced concrete special shear wall boundary element in compression. This paper comes from the second chapter of my dissertation and was published with the help of Carlos Arteta, Yi Shao, and Claudia Ostertag.

Abstract

Post-earthquake observations and laboratory tests reveal the needs for innovative solutions that can enhance the concrete compression ductility in the boundary elements of special structural walls. This study proposes a new boundary element design by utilizing hybrid fiber reinforced concrete (HyFRC). One full-scale HyFRC boundary element is tested in uniaxial compression and compared to three full-scale conventional concrete boundary elements that are compliant with ACI-318 codes. Results demonstrate that replacing conventional concrete by HyFRC can (1) control the early-stage surface damage, (2) improve the confinement for concrete core, and (3) delay the onset of longitudinal bar buckling. Relative to the conventional concrete boundary elements, which lose load capacity after spalling, the HyFRC boundary element exhibits a unique post-spalling load plateau and improves the compression toughness by more than 150%.

Hybrid fiber reinforced concrete special shear wall boundary element in compression - ScienceDirect

Siemens Engineering for Change Design Challenge

In 2020 I joined a team with Hadijah Nantambi S. and Kyle Gaise to submit an entry in the Siemens Innovate for Impact Design Challenge for an off-grid, cold storage room for rural farmers in Uganda. The design took top prize in the Zero Hunger track out of over 100 entries. The team has since partnered with Ecolife Foods and continues to develop the technology and prototype designs.

You can learn more about this project and more at HOME | Ecolife (ecolifefoods.org)

Ce-ment

Why on earth would I put a Beverly Hillbillies gif on a blog about concrete? Well because the subject of this scene is something that's always bothered me. You see, on the show, these beloved hillbillies constantly referred to their pool as a "Ce-ment Pond". I would like to get this off my chest once and for all - they should be calling it a "Concrete Pond". Okay okay, they’re supposed to be uneducated Hillbillies, they get a pass. But you, dear reader, do not. At least not after reading this post. 

Okay, so now the question is, why do I care so much? It's because there's a pretty large difference between cement and concrete. Cement refers to Portland cement, a powder formed from limestone and clay that's been put through a kiln and then ground up with gypsum to form a compound that will react with water and harden.

Portland cement

This resulting hardened cement paste, while strong, is very brittle and not all that useful as a building material. The real magic happens when we add sand and rocks; then we can finally call it concrete. 

So maybe our gang of hillbillies were actually cement scientists and were only referring to that component of the concrete, but somehow I doubt it. To most of you this is probably annoyingly pedantic, but it's something I needed to get off my chest. 

EURO-C 2018

This week I had the honor of presenting at the EURO-C Conference on Computational Modeling of Concrete and Concrete Structures. The research I presented involved simulation of reinforcement buckling of bars embedded in Hybrid Fiber Reinforced Concrete. It's been a topic of interest for me for several years, and will make up a large portion of my dissertation (which I keep saying I will start working on soon). 

There were many other compelling talks given regarding new and improved methods of modeling concrete, from micro-scale particle models all the way up to large-scale structural models. It is important to investigate concrete at all these scales, as the behavior appears different depending on the lens through which you're looking at it. I think this conference was successful in highlighting the many complexities that come with attempting to model a material such as concrete. 

The real highlight of this conference, however, was the setting. The venue was located in Bad Hofgastein, Austria, a quaint town nestled in the Gastein Valley with the Alps rising high on either side. I can not imagine a more scenic location for a conference. 

More information on the conference can be found at http://euro-c.tuwien.ac.at/home/ 

I do not know when proceedings will be made publicly available, but if you are interested in reading my paper feel free to contact me and I will send you a copy. 

ETH - Ultra-thin concrete roof

Researchers from ETH Zurich have built a prototype of an ultra-thin, curved concrete roof using innovative digital design and fabrication methods. The tested novel formwork system will be used in an actual construction project for the first time next year. Read more: https://www.ethz.ch/en/news-and-events/eth-news/news/2017/10/innovative-construction.html

A Concrete Beginning

Three basic ingredients*, but a world of possibilities. A material that almost everyone has interacted with in some way or another is one that few know anything about. I'm starting this blog as a way to change that, to inform people about concrete. There will be posts on the history of concrete, physical and chemical properties, new and updates on what's new in the world of concrete, bad concrete puns, and even some mix designs if you're interested in making your own high performance concrete. In short, there will be a little of everything related to this wonderful cementitious composite. 

*Portland cement, water, and aggregates. Some people might include air, or separate coarse and fine aggregate into two different categories, but I think it sounds catchier this way.