CemLit-IE: Schema-Constrained LLM Extraction for Traceable Cement Strength Databases

Sun Yanjie, Mengze Hong, Chen Jason Zhang, Haoyang LI


Abstract
Cementitious materials teams need machine-readable databases of compressive strength records to support mix-design optimization. However, manual curation of the literature is too slow and hard to scale. We present CemLit-IE, a five-stage zero-shot pipeline, converting raw PDFs into fully attributed records with provenance. The core challenge is that the relevant information is distributed across tables, text, and figures. Even though table-only extraction produces plausible numbers, the results are not auditable. CemLit-IE addresses this through a series of methods, including keyword-weighted page scoring, structured table injection, value-provenance schema, and review queue. On a benchmark of 20 papers with 655 expert-annotated records, CemLit-IE achieves a recall of 76.3% with 99.2% precision and 100% exact-match accuracy in a text-only model. The recall can be raised to 83.5% when figure reading is enabled. The ablation study shows that each design choice contributes to improving precision. As for the cost, a separate 270-paper journal-batch run extracted 2,039 strength records at $31.28 total API cost. All data and code are publicly released.
Anthology ID:
2026.emnlp-industry.98
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing: Industry Track
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Pepa Atanasova, Gholamreza Haffari, Minghan Wang
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
1663–1673
Language:
URL:
https://aclanthology.org/2026.emnlp-industry.98/
DOI:
Bibkey:
Cite (ACL):
Sun Yanjie, Mengze Hong, Chen Jason Zhang, and Haoyang LI. 2026. CemLit-IE: Schema-Constrained LLM Extraction for Traceable Cement Strength Databases. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing: Industry Track, pages 1663–1673, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
CemLit-IE: Schema-Constrained LLM Extraction for Traceable Cement Strength Databases (Yanjie et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-industry.98.pdf