(408) 640-6219  |  czynda@jjalbanese.com 
President's Comment
I have been in Gunite / Shotcrete industry for over 40 years started as a laborer, foreman, superintendent – owner. I have been asked to explain the difference between Gunite and Shotcrete almost every day for the past 30 years. The questions seems to always be the same what is the difference between the two.  In the Shotcrete process the answer is simple: The Aggregates and Cement Powder - are mixed completely with the water, creating Wet Mix Concrete.  SHOTCRETE IS CONCRETE.

I am a founding father for the ACI Nozzleman program which started over 12 years ago and a current C660 Shotcrete Certification committee voting member. I am a past president of the American Shotcrete Association and have been on the American Shotcrete Association executive board – vice president for over ten years.

In the past decade I have seen the world trend going towards Shotcrete (wet concrete mix) the need for an association to promote and educate this process is needed for the fast advancing concrete industry.

Thank You,
Chris Zynda
President Shotcrete Concrete Contractors Association
General Manager / JJA Shotcrete Operations
ACI Certified Examiner
Committee / ACI 506 -ACI 660
ASTM C/209
Approved ACI Examiner for Caltrans 

The Contractor is Key in the success of the Project

Which may include project specific mock-up's - These Pre- Construction test panels demonstrate quality control and verify the Nozzleman has the capability with the support crew including the intended mix to qualify the team to install the concrete for the project.

 Including qualifying the Support required by the Shotcrete / Concrete Contractor.

The Shotcrete Contractors Association has developed an education program that is current with all

ACI Concrete industry standards.

The Shotcrete Contractors Association works with 

ACI chapters thru-out US and Canada administering the ACI Shotcrete Nozzleman Certification program which includes both classroom education and practical field education including a Concrete specific Safety class.  Contact Shotcrete Concrete Contractors for session dates.

The Shotcrete  Contractors Association -  Non-profit origination of Contractors - Engineers and others with an interest in Shotcrete .

The Shotcrete Contractors Association offer's - Education / Training / Safety Program which includes  -  ACI Nozzleman Certification thru ACI Chapters - US & Canada  -

Description of Shotcrete 

Material is generally delivered with Ready- mix trucks per ACI 318 - ASTM C94 Standard specification for ready mixed concrete. The Aggregates are a combination of coarse and fine aggregates per ASTM C-33. Concrete is pumped thru a system with air-injected at the nozzle to increase velocity and improve the placement of the concrete. The concrete being placed may be vibrated and placed with or without the nozzle in congested and horizontal applications.

New Generation

In the early 1980’s the Concrete Industry takes a big step in the quality for mixing and batching ready mixed concrete, computer controlled ready mix plants are installed. Admixtures have become common and proven to increase the placement and durability of the concrete. The equipment used in the Shotcrete (wet mix concrete process) has changed full circle from the start in the mid 50’s.

Today's state of the art equipment is capable of pumping any slump and used in long distance tunnel projects as well as high rise concrete construction.

History of Shotcrete (wet mix concrete process)

Starting in the mid 1950’s wet mix Shotcrete was introduced to the construction industry – these primitive attempts proved to be very beneficial to the industry, thru the 1970’s numerous structures have been constructed with Wet Mix Concrete using the Shotcrete process as means and method to place the concrete.

Shotcrete is Concrete - 

 Conveyed through a hose and pneumatically projected at a adjustable velocity onto a surface, as a construction technique to install concrete.

(Dry Mix-Process) the material may come in a bag form or bulk, the material is conveyed with pneumatics with the water added at the nozzle .In the (dry process) the Nozzleman plays a most important role with the material being placed, the mix is propelled by air velocity

which creates turbulence creating fluxions at the nozzle, the Nozzleman will use a (circular motion -etc.) to compete the hydration at point of discharge.(Recommend adding 3%-4% moisture for all Dry bag material) this will minimize dust and help final  hydration of the placed mix .

(Wet Mix-process) the material is generally delivered with

ready-mix trucks per ACI 318-ASTM C94 standard specification for ready mix concrete. The aggregates are a combination of coarse and fine aggregates per ASTM 33 . The material is pumped with high pressure hydraulic concrete pumps thru a system which air is injected at the nozzle to increase the velocity

The concrete being placed may be vibrated and placed with or without the nozzle.