Thermal and shrinkage effects in high performance concrete structures during construction
Bibliographic record
Abstract
This project studies the prediction and prevention of cracking in high performance concrete due to temperature and shrinkage during construction.Models are developed to predict concrete physical properties, as well as thermal properties.Computer models are then developed to predict temperaturz development and distribution in concrete under field conditions.This information is the? used as input to determine the time-dependent stresses caused by temperature fluctuations and concrete shrinkage.During construction, the primary cause of temperature fluctuation is heat generated by cementitious mati ial hydration.A hydration model for high performance concrete is developed that considers the rate of hydration and the influence of concrete composition on heat of hydration.Concrete thermal properties, which influence the magnitude, distribution, and rate of temperature change, are also described.The hydration model is then incorporated into a three-dimensional, transient, finite element thermal analysis using an existing computer program FETAB3D as a basis to predict the temperature history and distribution in a concrete structure.The computer program FETAB3D, which takes into account variable thermal conditions including thermal radiation and boundary energy transfer, is modified further to account for multi-lift construction procedures, and to accept custom ambient temperature and solar radiation input files.To reflect these modifications, the computer program is renamed FETAB3DH.Physical properties of high performance concrete, such as tensile and compressive strength, elastic modulus, creep, and shrinkage are discussed and modeled as a function of concrete maturity.Using these material properties, concrete stresses due to temperature change and shrinkage are calculated using the commercially available structural analysis computer program, ABAQUS.The effects of creep are considered by using the general step-by-step method.The thermal and stress analysis techniques presented in this study are used to study the construction of the Confederation Bridge, in Easten Canada, and the Tsable River
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| 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 | 0.000 |
| 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 itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".