Download or read book Shotcrete Design and Installation Compliance Testing written by and published by . This book was released on 2015 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The National Institute for Occupational Safety and Health (NIOSH) conducted a research study to document and develop safe practices for the use of shotcrete as ground support in underground mines, particularly in underground metal mines operating in weak host rock. Shotcrete is the generic name for a mixture of cement, sand, fine aggregate, and water that is applied pneumatically and compacted dynamically under high velocity. The objective of this research is to reduce mine worker fatalities and injuries resulting from rockfall accidents. Although the information, techniques, and technology covered in this publication will impact both the mining and construction sectors, the primary audience is the mining industry with a focus on underground metal mines operating in weak ground conditions. The information and practices covered in this publication relating to the use of shotcrete can be put to use by mining professionals towards improving mine design and ground control plans. The guidance and practices reported in this document will help safety auditors, mining companies, and shotcrete suppliers in improving their shotcrete product specifications and the performance of ground support systems, evaluating ground control plans, and assessing shotcrete quality control. Ground control safety can be improved by providing these groups with a better understanding of the use of shotcrete in weak rock conditions, field test methods and equipment for measuring the strength properties of shotcrete directly at the mine site, and a practical means of conducting quality control during shotcrete applications. Development of Portable Test Machines: NIOSH researchers developed three portable test machines for determining shotcrete strength properties directly at the mine site. These portable test machines can be used to measure the early-age compressive strength of the shotcrete, the flexural load capacity and toughness of the shotcrete, and the installed quality and bond strength of the shotcrete that is applied to underground entries; this enables the test machines to be used to verify safe re-entry times. Onsite testing of as-placed shotcrete allows the mine personnel and shotcrete supplier to determine if the shotcrete is performing to design specifications. Using these shotcrete test machines directly at a mine site allows the support capabilities of the shotcrete to be evaluated in terms of the specific ground conditions, support methods, mining spans, and entry dimensions at the mine. As a result, mine design decisions regarding the use of shotcrete can be made from a much more informed position. Ultimately, this enhanced onsite knowledge of shotcrete strength properties and the quality of shotcrete application techniques can result in better ground support system designs and procedures, thereby reducing the number of fatalities and injuries associated with groundfall accidents. Shotcrete Characteristics and Application: When the shotcrete is applied in-cycle to underground mine surfaces as part of the ground support system, it becomes important to quantify when mining can safely resume under the material. As part of the overall ground support system, shotcrete is typically sprayed on the surface of an underground opening to stabilize the ground and prevent raveling. Shotcrete is also applied at lower water-to-cement ratios than concrete and develops its own unique strength characteristics. In addition, the quality of the applied shotcrete, the competency of the underlying rock, and the load-carrying capability of the shotcrete once cured are of critical importance. The significant shotcrete characteristics examined in this report are: slump, compressive strength, tensile strength, early strength, adhesion strength, and flexural strength. Of these shotcrete characteristics the engineering strength properties that are determined using early strength, adhesion strength, and flexural strength testing methods are the focus of this report. The significant shotcrete tests to determine characteristics examined in this research study are: 1. Slump Test - used to determine (wet) uncured shotcrete consistency. 2. Compression Test - used to measure cured shotcrete compression strength. 3. Tensile Test - used to measure cured shotcrete tensile strength. 4. Early Strength Partial-beam Test - used to measure shotcrete cure strength development over time. 5. Overcoring and Direct-tension Pull Test - used to measure cured shotcrete adhesion strength. 6. Round Determinate Panel Flexure Test - used to measure cured shotcrete load capacity and toughness." - NIOSHTIC-2

Download or read book Standard Practice for Shotcrete written by American Society of Civil Engineers and published by American Society of Civil Engineers. This book was released on 1995 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Specification for Shotcrete ACI 506 2 95 written by and published by . This book was released on 1995 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: This specification contains the construction requirements for the application of shotcrete.

Download or read book Standard Practice for Preparing and Testing Specimens from Shotcrete Test Panels written by American Society for Testing and Materials and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Sprayed Concrete Lined Tunnels written by Alun Thomas and published by CRC Press. This book was released on 2008-10-08 with total page 265 pages. Available in PDF, EPUB and Kindle. Book excerpt: Practising engineers on site, in the design office or in client organizations will find this book an excellent introduction to the design and construction of sprayed concrete lined (SCL) tunnels. The complex behaviour of the early age behaviour of the sprayed concrete requires careful management. This book covers all aspects of SCL tunnelling – from the constituents of sprayed concrete to detailed design and management during construction. Although there is a close interdependence between all the facets of sprayed concrete, few engineers have the right breadth of experience and expertise, and this urgently needs to be transferred to the wider engineering community. Disseminating essential information for tunnelling engineers, Sprayed Concrete Lined Tunnels is key reading for all involved in or studying the process.

Download or read book Compliance Testing for Probabilistic Design Purposes written by and published by . This book was released on 1998 with total page 105 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Shotcrete written by Dudley Robert Morgan and published by CRC Press. This book was released on 2022-03-29 with total page 577 pages. Available in PDF, EPUB and Kindle. Book excerpt: Shotcrete: Materials, Performance and Use is a comprehensive textbook covering the current state-of-the-art shotcrete technology. It provides an overview of the many and various uses of shotcrete. Shotcrete is well suited for construction of curvilinear structures (domes, shells, bobsleigh/luge tracks, etc.) and overhead shotcrete applications (seismic retrofit, repairs, ground support, etc.) that could not be constructed technically and/or economically using conventional formed, cast-in-place concrete construction methods. It contains chapters on history, shotcrete materials and mixture proportioning, performance, shotcrete research, equipment and shotcrete application. It is also comprised of shotcrete case history examples including buildings and structures, infrastructure repair and rehabilitation, ground support and shoring, underground support in tunnels and mines, swimming pools and spas, and, finally, architectural shotcrete. This text should be of interest to design engineers and architects considering the use of the technology, as well as academics. It serves as a useful guide to contractors using shotcrete in one or more of its many and various applications.

Download or read book Concrete for the Modern Age Developments in materials and processes written by Dr Atef Badr and published by Whittles Publishing. This book was released on 2017 with total page 1057 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume presents a wide-ranging review of the latest developments in concrete technology that have been largely missing from the global conference circuit. It the first major international event under the auspices of the Institute of Concrete Technology (ICT) and is appropriately located in the Middle East at the heart of a construction boom. Themes covered include admixture technology, durability, mix design, special cements and supplementary materials, reinforced concrete and sustainability. The 39 papers provide interesting theory and applicable practice blended with research findings – from the application of 3D printing to performance-based specifications and the role of concrete in the development of Oman – to produce a volume of value to many engineers and technologists. Founded in 1972, The Institute of Concrete Technology (ICT)’s mission is to preserve and promote concrete technology as a recognised engineering discipline and consolidate the professional status of practising concrete technologists worldwide. It is the concrete sector’s professional development body, operating internationally, with some 500 members in more than 30 countries. It is an awarding body for qualifications in concrete technology and a facilitator of continuing professional development (CPD) and networking opportunities. Our partner in this conference, The Military Technical College in Muscat, Oman, was established with the intent of becoming a Center of Excellence in engineering education. Located in one purpose-built, state-of-the-art, well-resourced center, the intent is that MTC will be amongst the world's best in the field of military and applied non-military technological education and training providers in the world.

Download or read book Standard Specifications for Construction of Roads and Bridges on Federal Highway Projects written by United States. Federal Highway Administration and published by Government Printing Office. This book was released on 2014 with total page 766 pages. Available in PDF, EPUB and Kindle. Book excerpt: Standard Specifications for Construction of Roads and Bridges on Federal Highway Projects is issued primarily for constructing roads and bridges on Federal Highway projects under the direct administration of the Federal Highway Administration. It is also used by the U. S. Forest Service and other Federal agencies on their projects. These specifications are cited as "FP-14" indicating "Federal Project" Standard Specifications issued in 2014 and contain both United States Customary and Metric units of measure. This book outlines the contractual process, including bids, Scope of Work for projects, including materials, construction requirements, equipment, glossary of terms, and much more. Road construction companies, and supply management vendors for the equipment, tools, and pipes needed for constructing Federal highways, as well as engineers, Federal, state, and local Government agencies may be interested to have a copy of this authoritative work available as a reference for any current, and/or future road construction projects

Download or read book Field use Early strength Shotcrete Test System written by and published by . This book was released on 2011 with total page 2 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Objective: To develop a practical method of measuring shotcrete early strength ansite in the first six hours after application using a partial beam test standard, ASTM C 1 16-90. Determining the early-strength development of as-sprayed shotcrete can improve mine safety by identifying appropriate reentry times and providing a convenient means of quality control during application. A more thorough understanding of shotcrete early strength will lead to improvements in ground support practices, thereby preventing ground falls and reducing mine roof-fall accidents. Background: When shotcrete is used as part of a multi component ground support system, it is important to know when the material has developed enough strength to be self-supporting and allow for reentry and emplacement of the remaining support elements that require drilling of the shotcrete layer without degradation. Typical reported values for this threshold strength for North American mines range from 1 to 1.6 MPa (145 to 233 psi) [O'Toole and Pope 2006], with a compressive strength equivalent to 1 MPa (145 psi) being the norm [Rispin et al. 2003; O'Toole and Pope 2006]. Typical ground control support includes a shotcrete flash coat 19- to 25-mm (3 /4- to 1-in) thick, followed by screen, plates, bolts, and a second layer of shotcrete bringing the combined thickness to 75 to 100 mm (3 to 4 in). In areas requiring rehabilitation, the second layer of shotcrete is plated and bolted as well. While testing cored samples after 24 hours is standard, this is not practical for the one- to six-hour period following application when shotcrete unconfined compressive strengths are less than 10 MPa (1,450 psi). Indirect methods are typically used to determine shotcrete strength during the early stages of curing because the partially cured or green material is difficult to sample and test. While problems with inconsistent test results have been reported with the penetrometer-type devices, beam molds have been used successfully for creating shotcrete test specimens in the United States and Canada. Operating the Partial Beam Test System: The test unit is a self-contained, servo-controlled, stiff-frame press. Partial beam test samples are obtained by spraying shotcrete into 102- x 102- x 152-mm (4- x 4- x 6-in) mold boxes. After the samples have been sprayed, tests are conducted at one-hour intervals over the next six hours (one- through six-hour tests). The shotcrete samples are carefully demolded by disassembling the mold fixtures and removing the enclosed sample. Next, a shotcrete sample is placed in a specialized testing fixture and centered under the loading head of the test machine. When the test sequence is initiated, a programmable-logic-controller- (PLC) driven press applies a fixed-rate load to the sample. The load profile is shown on a graphical output display, and the measured test parameters (time, displacement, and load) are stored on a thumb drive. Once the operator observes a well-defined peak in the load profile curve, the test is completed and the test machine's loading platen can be returned to its initial starting position. Peak load is typically reflected by the development of large vertically oriented cracks along the platen-to sample contact edges, which are indicative of the failure plane. There is a marked difference in early-strength gain between sprayed and cast shotcrete. The cast shotcrete samples have a similar strength gain profile to that of cast concrete samples."--NIOSHTIC-2.

Download or read book Standard Test Method for Obtaining and Testing Drilled Cores of Shotcrete written by and published by . This book was released on with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book FHWA International Scanning Tour for Geotechnology September October 1992 written by and published by . This book was released on 1993 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Shotcrete Design Guidelines written by G. Collins and published by . This book was released on 2005 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book ACI Manual of Concrete Inspection written by American Concrete Institute and published by . This book was released on 1957 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Support of Underground Excavations in Hard Rock written by E. Hoek and published by CRC Press. This book was released on 2000-01-01 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: The safe and economical construction of tunnels, mines, and other subterranean works depends on the correct choice of support systems to ensure that the excavations are stable. These support systems should be matched to the characterstics of the rock mass and the excavation techniques adopted. Establishing the support requirements, designing support systems and installing these correctly are essential elements in safe underground construction. This is a comprehensive and practical work which also gives access to user-friendly computer programmes which enable the investigation and design of support techniques. Details on how to obtain this software are also included in the book.

Download or read book Cal OSHA Pocket Guide for the Construction Industry written by and published by . This book was released on 2015-01-05 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Cal/OSHA Pocket Guide for the Construction Industry is a handy guide for workers, employers, supervisors, and safety personnel. This latest 2011 edition is a quick field reference that summarizes selected safety standards from the California Code of Regulations. The major subject headings are alphabetized and cross-referenced within the text, and it has a detailed index. Spiral bound, 8.5 x 5.5"

Download or read book Shotcrete Elements of a System written by Stefan Bernard and published by CRC Press. This book was released on 2010-02-10 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the last twenty years we have witnessed a revolution in ground stabilization in both underground and above-ground applications, thanks largely to the widespread adoption of shotcrete as a medium for support. Shotcrete technology continues to evolve and improve as its utilization increases. From relatively obscure and sporadic beginnings, it ha