Title:
Mass Shotcrete Wall Construction and Thermal Control Plan
Author(s):
Lihe Zhang, Dudley R. Morgan, Iain Kirk, Anastasia Rolland, and Robert Karchewski
Publication:
Materials Journal
Volume:
118
Issue:
3
Appears on pages(s):
71-82
Keywords:
compaction; consolidation; encapsulation; mass concrete; mass shotcrete; nozzleman; shotcrete; temperature differential; thermal control plan
DOI:
10.14359/51730423
Date:
5/1/2021
Abstract:
Wet-mix shotcrete has been used more and more for structural applications in the past few decades. Recently, wet-mix shotcrete was successfully used to construct a mass structural wall with congested reinforcement and minimum dimensions of 1.0 m in a sewage treatment plant. A low-heat shotcrete mixture that included up to 40% slag was proposed for shotcrete application. A preconstruction mockup was shot to established proper work procedures for shotcrete application and qualify the shotcrete mixture and shotcrete nozzlemen. Extraction of cores and cut windows from the mockup confirmed proper consolidation around the congested reinforcement. A thermal control plan was developed, which included laboratory and field testing requirements, thermal analysis modeling with a three-dimensional (3-D) finite element program, and thermal control requirements, including installation of cooling pipes and thermal blankets. Shotcrete proved to be an efficient means for mass concrete structural construction. Thermal control for mass shotcrete construction was studied, and the proposed thermal control plan was proved to function properly. The general guidance for mass shotcrete construction is provided.
Related References:
1. ACI Committee 506, “Guide to Shotcrete (ACI 506R-16),” American Concrete Institute, Farmington Hills, MI, 2016, 8 pp.
2. ACI Committee C660, “CP-60 Craftsman Workbook for ACI Certification of Shotcrete Nozzleman,” American Concrete Institute, Farmington Hills, MI, 2015, 120 pp.
3. Zhang, L.; Morgan, D. R.; and Mindess S., “Comparative Evaluation of the Transport Properties of Shotcrete Compared to Cast-in-Place Concrete,” ACI Materials Journal, V. 113, No. 3, May-June 2016, pp. 373-384.
4. Zhang, L., “Air Content in Shotcrete: As-Shot vs. As-Batched,” Shotcrete, Winter 2012, pp. 50-54.
5. Zhang, L., “President’s Memo,” Shotcrete, Winter 2019, pp. 4-5.
6. Hanskat, C.; Holland, T. C.; and Suprenant, B. A., “Shotcrete Incorporated into ACI 318-19 Building Code,” Concrete International, V. 41, No. 12, Dec. 2019, pp. 31-35.