Modelling efforts and control over realistic data

I have been recently busy with trying to improve damage model by implementing better ways to represent variety in material definitions. After finishing the analysis of NanoIndent results now we have the opportunity to assign this information (basically E-modulus and Strength values driven from hardness) for different phases in the system.

I recently introduced

• Random distribution based on Nano Indent test results - using mean and variance of data
• Triangular random generation of mesh with around 112000 elements to represent 10cm x 10cm sections
• Probabilistic distribution of reaction (in this case expansion) based on petrographic identification of reactive phases in aggregates (different for each mix design)
• and implementation of saturated cracks by updating the loading system while simulation is running (by introducing plastic behavior stage non elements stress strain curves)

Here are some representative images;

Histogram showing distribution of E values grouped by phases (Agg-Mortar-Bond-Void)

Heat map of E Mod values based on Digital image, Mesh geometry representing heterogeneity in aggregates and mortar

Initial Load elements with varied Intensities

Fracture evolution after 20000 simulation steps

PhDLife: The Thesis Repulsor Field

Proof loading on the viaduct Vlijmen-Oost affected by Alkali-Silica Reaction

The viaduct Vlijmen-Oost, affected by Alkali-Silica Reaction, was proof loaded on 6 November 2013.
This tested was performed in order to asses the structural response of the bridge and the its current capacity.
The viaduct was already monitored from several years in the contest of the A59 project. The development of ASR was assessed in 1997, however the bridge expansion appear to be still limited.

This project was conducted by Rijkswaterstraat in collaboration with 3 IS2C project (PAT-ASR, Smart Proof Loading and InfraWatch).

Article in the local news paper.

The BELFA truck used to perform the proof loading.

Part of the team (from left to right): Rita Esposito (TUDelft), Max Hendriks (TUDelft), Johan De Boon (TUDelft), Sonja Fennis (TUDelft) and Ane de Boer (Rijkwaterstrat).

Structural Synergy 2013

Pat-Asr teammate Rita Esposito gave a pitch talk on Structural Synergy Symposium in TU Delft, 12th Sep.

Thank you Rita,

Textbook AAR Damage in concrete samples

We are currently carrying out numerous Damage Rating index analysis on RILEM test (AAR-4.1 and AAR-3) samples. Along the process of images we frequently come along with text-book examples of ASR damage in our Lab samples. Here is one under UV light.

Sample info:

Prism from RILEM AAR-3 Test on Norwegian Aggregates (Original Mix)
Age 364 days old @ 38°C RH 100%. No Alkali boosting.

Editor's Note: It's weird how we (ASR researchers) enjoy cracks (evidences) in our samples, while it is absolutely bad news for structures and clients.