For Guidance (+91) 7550 227 228 (WhatsApp Only)

Get Latest Civil Projects in your Email

Characterization of Delayed Ettringite Formation in Bridges

The research investigated the significance of Delayed Ettringite Formation (DEF) presences in the Maryland Bridge Inventory. The objective of the research included investigating possible presence of DEF, correlations between the presence of DEF in cast-in-place concrete and moist map cracking, and correlations between presence of DEF in cast-in-place concrete and air entrainment agents (AEA).

The research required coring a target population, so that scanning electron microscope (SEM) with energy dispersive analysis x-ray (EDAX) could be utilized to identify DEF in the concrete. Combination of visual identification, SEM and elemental identification with EDAX are used to verify the presence of DEF in the concrete samples. The research was conducted in two phases with the first suggesting a possible link between moist map cracking and DEF.

The research identified numerous ettringite morphologies in bridge concrete. Characterization of the ettringite morphologies suggested that lamellar ettringite could be linked to DEF-related damage. From this work, a second phase was developed to establish a link between degree of moist map cracking and DEF. Furthermore, other research showed that ettringite grew well in a solution of AEA. The second phase research developed a population to test both hypothesis and attempted to show positive or negative correlations between these two theories and DEF presence.

Phase 2 research shows no correlation between concrete mixes with AEA and DEF. Therefore, the conclusion is that AEA does not have any measurable adverse effects regarding DEF. Whereas, the research shows a strong correlation between widespread moist map cracking and significant DEF quantities, but that a DEF presence is not necessarily indicative of DEF-related damages. Once a threshold is exceeded, DEF-related damages are observed and are found throughout the affected concrete.
Source: University of Maryland
Author: Ceary, Micah

Download Project

>> 50+ Project Topics with Free Project Materials on Bridges and Flyovers for Civil Students

>> Structural Engineering Project Topics List with Free PDFs

For Free Civil Project Downloads:
Enter your email address:
( Its Free 100% )

Leave a Comment

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>