1
25-045
Improving Shotcrete Application Through In-House Training
and Field Support for Nozzlemen: A Case Study
Doandy Yonathan Wibisono
PT Anggun Permai Tekindo, Indonesia
ABSTRACT
Shotcrete is a versatile and widely utilized rock support
material in mining and civil engineering projects due to its
adaptability, strength, and efficient application. It imme-
diately stabilizes rock surfaces, effectively controlling loose
materials and preventing rockfalls in underground excava-
tions. This paper focuses on assessing and analyzing data
from observations of nozzlemen (shotcrete sprayers) during
primary ground support activities in an underground mine.
The study highlights the importance of nozzlemen’s skills in
ensuring the quality of shotcrete application, which is criti-
cal for underground mining operations’ structural integrity
and safety. A comprehensive training program and field
support were implemented to enhance the nozzlemen’s pro-
ficiency. The training set covered theoretical knowledge and
practical techniques to improve shotcrete application daily.
Proficiency improvement was assessed using quantitative
metrics, with rebound percentages decreasing by 5–14% as
nozzleman competency increased. The results of this initia-
tive showed significant improvements in shotcrete quality,
including increased efficiency, reduced waste, and fewer
reworks or rehabilitations. The findings aim to contribute
to a broader understanding of best practices in shotcrete
application and nozzlemen training, ultimately enhanc-
ing ground support application measures in the mining
industry.
Keywords: shotcrete, in-house training, optimization.
INTRODUCTION
Shotcrete is the generic name for cement, sand, and fine
aggregate concretes, which are applied pneumatically and
compacted dynamically at high velocity. The introduction
of the Q-system in the 1970s revolutionized underground
excavation support, fostering significant advancements in
rock bolt designs and fiber-reinforced shotcrete technolo-
gies (Barton et al., 1974). These innovations enhanced
safety and efficiency, cementing sprayed concrete as a vital
ground support element in underground mining opera-
tions (Bernard, 2010 Maidl et al., 2013). Shotcrete offers
passive confinement to excavated rock surfaces, where this
method replaced traditional cast concrete structures, even
in settings with high-quality rock masses.
Shotcrete application in North America dates back
to 1914 when dry-mix shotcrete (gunite) was used at the
Brucetown Experimental Mine to prevent rock degradation
caused by exposure to water and air (Kobler, 1966). Over
subsequent decades, shotcrete gained traction for semi-
structural applications in tunnels and mines. For example,
annual shotcrete requirements in block cave mining opera-
tions often exceed 80,000 m3 (See Figure 1), highlighting
the need for stringent quality control across production,
transportation, and application processes (Erismann et al.,
2018). Modern advancements in chemical admixtures have
refined their performance, enabling improved durability,
faster application, and seamless integration into contempo-
rary mining practices.
The quality of shotcrete application plays a crucial role
in ensuring the stability and safety of underground excava-
tions (Bolduc et al., 2010). Material properties, equipment,
and site preparation are critical factors in shotcrete applica-
tion however, the expertise of nozzle operators (nozzlemen)
is equally vital. Without adequate training and support,
25-045
Improving Shotcrete Application Through In-House Training
and Field Support for Nozzlemen: A Case Study
Doandy Yonathan Wibisono
PT Anggun Permai Tekindo, Indonesia
ABSTRACT
Shotcrete is a versatile and widely utilized rock support
material in mining and civil engineering projects due to its
adaptability, strength, and efficient application. It imme-
diately stabilizes rock surfaces, effectively controlling loose
materials and preventing rockfalls in underground excava-
tions. This paper focuses on assessing and analyzing data
from observations of nozzlemen (shotcrete sprayers) during
primary ground support activities in an underground mine.
The study highlights the importance of nozzlemen’s skills in
ensuring the quality of shotcrete application, which is criti-
cal for underground mining operations’ structural integrity
and safety. A comprehensive training program and field
support were implemented to enhance the nozzlemen’s pro-
ficiency. The training set covered theoretical knowledge and
practical techniques to improve shotcrete application daily.
Proficiency improvement was assessed using quantitative
metrics, with rebound percentages decreasing by 5–14% as
nozzleman competency increased. The results of this initia-
tive showed significant improvements in shotcrete quality,
including increased efficiency, reduced waste, and fewer
reworks or rehabilitations. The findings aim to contribute
to a broader understanding of best practices in shotcrete
application and nozzlemen training, ultimately enhanc-
ing ground support application measures in the mining
industry.
Keywords: shotcrete, in-house training, optimization.
INTRODUCTION
Shotcrete is the generic name for cement, sand, and fine
aggregate concretes, which are applied pneumatically and
compacted dynamically at high velocity. The introduction
of the Q-system in the 1970s revolutionized underground
excavation support, fostering significant advancements in
rock bolt designs and fiber-reinforced shotcrete technolo-
gies (Barton et al., 1974). These innovations enhanced
safety and efficiency, cementing sprayed concrete as a vital
ground support element in underground mining opera-
tions (Bernard, 2010 Maidl et al., 2013). Shotcrete offers
passive confinement to excavated rock surfaces, where this
method replaced traditional cast concrete structures, even
in settings with high-quality rock masses.
Shotcrete application in North America dates back
to 1914 when dry-mix shotcrete (gunite) was used at the
Brucetown Experimental Mine to prevent rock degradation
caused by exposure to water and air (Kobler, 1966). Over
subsequent decades, shotcrete gained traction for semi-
structural applications in tunnels and mines. For example,
annual shotcrete requirements in block cave mining opera-
tions often exceed 80,000 m3 (See Figure 1), highlighting
the need for stringent quality control across production,
transportation, and application processes (Erismann et al.,
2018). Modern advancements in chemical admixtures have
refined their performance, enabling improved durability,
faster application, and seamless integration into contempo-
rary mining practices.
The quality of shotcrete application plays a crucial role
in ensuring the stability and safety of underground excava-
tions (Bolduc et al., 2010). Material properties, equipment,
and site preparation are critical factors in shotcrete applica-
tion however, the expertise of nozzle operators (nozzlemen)
is equally vital. Without adequate training and support,