Pdf 32 concepts of shotcrete technology research paper. In this document the term shotcrete is defined as mortar or concrete conveyed through a hose and pneumatically projected at high velocity onto a surface or substrate. Shotcrete in tunnelling and mining tu bergakademie freiberg. Various slump have equal workability workable slump the application of the same concrete mix with 8.
Shotcrete accelerator is a noncaustic accelerator primarily used in shotcrete applications. There is a marked difference in earlystrength gain between sprayed and cast shotcrete. Although it may be reassuring to have properly qualified nozzlemen on the project, it cannot be assured that the quality of inplace shotcrete will be. Vogt swedish cement and concrete research institute, sweden abstract. Decorative products euclid chemicals line of decorative products increte systems is renowned throughout the industry as the singlesource solution for all your decorative concrete needs. Chapter 2 types of shotcrete and applications corps of.
Comparative cost of shotcrete per square foot application of kalmatron admixtures to shotcrete and plaster mixes replaces, substitutes, and eliminates the list of products dedicated to provide targeted certain function. Advances in the development of the high range water reducing admixtures, pumping aids, and concrete pumping equipment since about 1960 have greatly reduced these problems, and wet mix shotcrete is now being used more frequently in repair construction. Quality control department basalite concrete products vancouver, ulc. It results in cost reduction taken per square foot by at 6 to 10 times as it shown on table below. International tunnelling association working group on shotcrete use. Intro to sprayed concrete sprayed concrete association. In some areas gunite has been used to denote smallaggregate shotcrete and mortar mixtures, and shotcrete to denote largeaggregate mixtures. Shotcrete shall not be used for any repair greater than 6 in.
We can custom blend to meet projectspecific requirements. Introduction to the basic technology of sprayed concrete. In the 1950s, wetmix shotcrete, the use of coarse aggregate in both processes, the rotary gun for drymix shotcrete, and more efficient concrete pumps for wetmix shotcrete were introduced. Monolithic shotcrete for swimming pools no cold joints.
Shotcrete, the quarterly publication of asa, is the leading magazine of the shotcrete industry, and is designed to educate and promote the use of shotcrete as a method of placing concrete. Guide to shotcrete paragraph a1, aci 1991d, and other aci 506 documents. Concrete institute aci conventions, and the term shotcrete will be used throughout this guide. To receive documents or other information about occupational safety and health.
Microsil shotcrete nav and nv not available nap and np not applicable 5 section 9 preparation date of msds prepared by. Efficiency allows for over 150 metric tonnes of drymix preblended material to be produced in an 8 hour shift. From stamping tools and form liners to integral pigments and overlays, these products provide a highquality solution to any project. This manual supersedes em 111022005, dated 10 september 1982. Unlike castinplace concrete, the success in applying shotcrete is mostly dependent on the skill and experience of the shotcrete installation crew, especially the nozzleman. The term shotcrete was first defined by the american railway engineers association area in the early 1930s. Quick set shotcrete accelerator basalite concrete products. It is not intended to be a comprehensive specification or standard. For proper adhesion, the concrete must have a fractured aggregate profile.
Comparative cost of shotcrete per square foot admixtures to. Removal of any anti adherents or loose materials must be accomplished mechanically. Shotcrete is the sprayed concrete, which was first used in pennsylvania. The application takes place pneumatically or hydraulically through a spray nozzle. You select the composition and properties according to your project specifications. Pdf fundamentals of shotcrete application and bond strength. Features microsilica modified may receive coatings in as few as 48 hours may be applied overhead, vertically and. Gunite 7000 features micro silica for added density, tensile and flexural strength.
Aci documents are requested to contact aci via the errata website at documenterrata. Multicrete shotcrete sprayable concrete for concrete maintenance, underground mining. It is also suitable for use as a set accelerator in some other portland cement products such as concrete mixes. Water solution of cement with kfa is a viscous electrolyte, giving low slump with high workability, pumpability and. Guaranteed quality as we produce shotcrete in our own concrete plants, we. Not your fathers gunite registration is requi this 1hour seminar will introduce the audience to the shotcrete process for placing concrete in a wide variety of structural and geotechnical applications. Shotcrete is sprayed concrete consisting of cement, sand, and fine aggregate. If formed concrete repair is used for locations that have reinforcement with less than 0. Shotcrete is a readymixed concrete intended for direct wetspraying on delivery. Concrete rehabilitation microsil shotcrete may be used in combination with steel fibre reinforcement to enhance load carrying capacity and with a noncaustic shotcrete accelerator to provide high early strengths and fast set times. A shotcrete testing standard, astm 155005 round determinate panel rdp test, was designed to replicate the typical shotcrete loading conditions in.
The shotcrete process allows concrete to be placed without forms, into complex shapes, vertically, and overhead. The type shotcrete equipment are suitable for bigger fracture surface, project which need big. The australian shotcrete society comprises industry professionals focused on the ongoing development and promotion of shotcrete as a construction material. Cracking of shotcrete in tunnels has in recent years become a problem in sweden. Nevertheless, what everyone agrees on is that there are two processes involved when it comes to spraying concrete or mortar pneumatically through a spraying. Jul 06, 20 shotcrete is today an allinclusive term that describes spraying concrete or mortar with either a dry or wet mix process. Dampen the surface thoroughly with clean water to ssd condition or use an epoxy bonding agent.
We do the same in this paper, using shotcrete and concrete. C1436 standard specification for materials for shotcrete. Shotcrete set accelerator technical data sheet chloride free designed for use with shotcrete description multicrete shotcrete set accelerator is a chloridefree, dry powder accelerator designed for use with shotcrete. Many improvements were made to wetmix equipment, primarily concrete pumps and materials, in the 1970s and 1980s. It can be classified in two processes one of which, called the dry. This guideline can only be used for steel fibre reinforced shotcrete, and not for synthetic fibre concrete with low modulus of young e concrete, spraycrete, airblown mortar and concrete, gunned concrete, and others. Designed for wet or dry shotcrete applications to repair deteriorated concrete, where a high density overlay is required. Lagerblad division of concrete structures, royal institute of technology kth, stockholm, sweden l. Best practices of using shotcrete for wall fascia and.
There are, however, m any variations of this procedure and a few are listed below. Shotcrete accelerator has two main effects on shotcrete. They are structural repair materials for bridges, tunnels, parking garages, ramps, beams, piers, sewer pipes and dams. Shotcrete dot meets the requirements for type fa grade fr class 1 according to astm c 1480. Vertical shaft kilns were replaced with rotary kilns and ball mills were used for grinding cement. Concepts of shotcrete technology seminar report, ppt, pdf. Mecmesins shotcrete penetrometer provides accurate readings of the forces required to penetrate sprayed or poured concrete during the first few hours of development, giving a reliable indication of compressive strength. An analysis of flexural strength and crack width for fiber. Shotcrete design and installation compliance testing. Shotcrete earlystrength values obtained from cast and shot samples using the test system are shown in figure 4. Shotcrete is a timeproven method to quickly and costeffectively place concrete with a minimum of formwork. Properly applied shotcrete is a structurally sound and durable construction material which exhibits excellent bonding characteristics to existing concrete, rock, steel, and many other materials.
Sep 05, 2015 conclusion the use of shotcrete to build new concrete structures as well as to restore and repair existing structures is well known and documented and it is perhaps the most diverse method available for concrete construction. Tytro hc cement hydration control admixture allows optimal logistical operations by extending the working life. Gunite 7000 micro silica modified shotcrete gunite 7000 micro silica modified shotcrete mortar is a single component, micro silica shotcrete available in both wet 7000w or dry formulations 7000d. The author grants to chalmers university of technology and university of. Shotcrete products should be applied only by an experienced, certified nozzleman.
Its accuracy and portability make it ideal for onsite testing to bs en iso 14488 method a and related standards. To receive documents or other information about occupational safety and. Shotcrete concrete repairing techniques civildigital. Rearrange individual pages or entire files in the desired order. The concrete is compacted by the impact energy and can be sprayed onto a. Stateoftheart specifications for shotcrete rehabilitation projects. Introduction to shotcrete applications ced engineering.
Gunite is a trademarked name that is incorrectly used to describe the drymix shotcrete process shotcrete emerged as the only acceptable industry term to correctly describe pneumatically applied concrete. Aci documents are requested to contact aci via the errata website at. Nevertheless, what everyone agrees on is that there are two processes involved when it comes to spraying concrete or mortar pneumatically through a spraying gun nozzle at high velocity onto a surface. The series wet shotcrete system equipment are highend equipment with top design and manufacture. Shotcrete also known as spraying concrete, has exactly the same basic ingredients as an ordinary concrete i. The preferred term today for all gunned material is shotcrete, regardless of the aggregate size. Shotcrete o r sprayed concrete is a method of placement where concrete is sprayed at high velocity onto a receiving surface.
There are, however, m any variations of this procedure and a. Tm safety data sheet shotcrete multicrete systems inc. Explore concepts of shotcrete technology with free download of seminar report and ppt in pdf and doc format. Setting and hardening accelerator for shotcrete shotcrete accelerator. Other means of identification product family recommended use restrictions on use manufacturer emergency phone no. They can be used for structural concrete in vertical, horizontal and overhead surfaces. Mar 24, 2014 wet mix shotcrete, as a result, may experience significantly more cracking problems due to the excess water and drying shrinkage. A key activity of the society is the provision of guidance to designers and practitioners on current and effective best practice. Material safety data sheet basalite concrete products. The cast shotcrete samples have a similar strength gain profile to that of cast concrete samples. Also explore the seminar topics paper on concepts of shotcrete technology with abstract or synopsis, documentation on advantages and disadvantages, base paper presentation slides for ieee final year civil engineering ce or ieee civil construction btech, be, mtech students for the year. It provides rapid setting or stiffening so the newly applied shotcrete can begin to support almost immediately. However, shotcrete may also sometimes be used incorrectly to distinguish wetmix from the drymix method.
However, many members of the industry will use the terms interchangeably when the reference to the shotcrete process is implied. A shotcrete testing standard, astm 155005 round determinate panel rdp test, was designed to replicate the typical shotcrete loading conditions in a mine or tunnel and gives. This guideline can only be used for steel fibre reinforced shotcrete, and not for synthetic fibre concrete with low modulus of young e shotcrete accelerator description. The use of this innovative technology is increasing day by day and procedures for its proper performance are well. The specification documents state that wet mix shotcrete equipment must meet aci 506r.
Shotcrete is sprayed concrete consisting of cement, sand, and fine aggregate that is. Pdf fundamentals of shotcrete application and bond. Multicrete shotcrete 0100 may 17, 2018 page 1 6 safety data sheet. Shotcrete has been the construction tool of choice for pools, tunnels, domes, tanks, foundation. This specification covers the materials for use in hydrauliccement concrete mixtures to be placed by wetmix and drymix shotcreting. Shotcrete should be installed in accordance with the provisions of the national or local building code and the american concrete institutes recommended practices aci 506r90, guide to shotcrete. This guideline can only be used for steel fibre reinforced shotcrete, and not for synthetic fibre concrete with low modulus of young e 694. The end result is a concrete structure built with the shotcrete process. Specified shotcrete bond strength for shotcrete to properly prepared concrete substrates generally ranges from 100 to 150 psi 0. Shotcrete is an allinclusive term for spraying concrete or mortar with either a dry or wet mix process.
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