Performance of Lap Splices in Concrete Masonry Shear Walls
Bibliographic record
Abstract
This research investigated the performance of lap splices of deformed reinforcing bars in concrete masonry shear walls. Variables investigated in this study include length of lap, size of bar, concentrated versus distributed flexural reinforcement, reduced cover resulting from bars offset in the cells, and method of testing. Nine concrete masonry shear walls incorporating flexural reinforcement lap splices at the bases of the walls were constructed and subjected to in-plane cyclic loading. Additionally, nine concrete masonry panels incorporating identical lap splices were constructed and subjected to direct tension loading. Results from this study indicate no significant differences in the performance of a lap splice tested in direct tension and in-plane flexure. This finding supports the validity of the large amount of data and resulting code design equation based on direct tension loading of lap splices. Results show that reduced masonry cover significantly affects lap performance, supporting the need to address cover for lap splice design. Walls containing No. 6 (M#19) bars offset in the cells performed poorly with respect to ultimate load resistance, displacement capacity, and peak longitudinal reinforcement stresses compared to walls with similar amounts of reinforcement distributed in the center of the cells, even when provided with lap lengths of 60 bar diameters. For the parameters considered in this study, the current MSJC lap splice provisions predicted the performance of lap splices for No. 6 (M#19) bars centered and offset in the cells with reasonable accuracy. However, the provisions appear to be overly conservative for lap splices of No. 8 (M#25) bars by roughly 20%, possibly as a result of confinement provided by transverse reinforcement present in the walls. In contrast, test results indicate little or no benefit was provided by the transverse reinforcement for walls containing lap splices of No. 6 (M#19) bars.
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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 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 | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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".