Title:
Development of Wet-Mix Shotcrete with Portland-Limestone Cement
Author(s):
Lihe (John) Zhang, Matthew Zhang, Dudley R. (Rusty) Morgan, and Sidney Mindess
Publication:
Materials Journal
Volume:
123
Issue:
2
Appears on pages(s):
103-112
Keywords:
alkali-free accelerator (AFA); early-age compressive strength development; flexural toughness; ground support; portland-limestone cement (PLC); residual tensile strength; shotcrete; Type GUL; Type I
DOI:
10.14359/51749444
Date:
3/1/2026
Abstract:
Portland-limestone cement (PLC) is being more and more specified and used in wet-mix shotcrete construction for ground support in tunnels and mines across the United States and Canada. The most widely used cement of Type GU (general use) in Canada and Type I in the United States is being replaced by Type GUL (general-
use limestone) in Canada and Type IL in the United States. There is no significant research being conducted on the performance of shotcrete made using PLC, including plastic properties, early-age strength development, compressive strength development, and, when fibers are added, flexural toughness and residual tensile strength development. This paper presents studies on the properties of wet-mix shotcrete produced with PLC. Results show that PLC requires a higher dosage of alkali-free accelerator (AFA) to achieve similar development of early-age compressive strength compared to shotcrete made with portland cement (PC). Development of compressive strength at 7 and 28 days for shotcrete made with PLC is similar to shotcrete made with PC. When both steel and macrosynthetic fibers are used in wet-mix shotcrete made with PLC, development of residual tensile strength with notched beams and flexural toughness for round determinate panels is also similar to that for wet-mix shotcrete produced with PC. Future research on wet-mix shotcrete with Type GUL cement is also discussed.
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