Biodeterioration of Concrete Sewer Pipes: State of the Art and Research Needs
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
Biodeterioration of concrete sewers is a common problem that results in concrete disintegration and significant damage. Two stages are normally identifiable in the process: an initiation stage, during which the concrete pore water pH is reduced from an initial value of over 12 to a value of about 9 by ingress of hydrogen sulfide gas and carbon dioxide (carbonation) and subsequent reaction with the hydrated cement paste; and a second stage, active biodeterioration, during which microorganisms excrete sulfuric acid that attacks the hydrated cement paste (HCP). Various national codes and standards provide some guidance to mitigate this problem. Sulfur-oxidizing microorganisms growing on the sewer walls have been isolated as the main culprit, but other phenomena come into play before biodeterioration occurs. Steady-state biodeterioration rates of 3 mm/year have been proposed in the literature. A detailed literature review was conducted to evaluate the various aspects of concrete biodeterioration and determine further research needs. This state-of-the-art report summarizes the deterioration mechanisms involved in biodeterioration of concrete sewers and the work necessary to complete the modeling of this phenomenon. A conceptual model of the processes is presented.
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Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.002 | 0.006 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it