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Technical papers available in HTML or PDF formatAlex Naudts and Eric Landry "New On-site wet milling technology for the preparation of ultrafine cement based grouts" Abstract The use of ultrafine cement-based grout has been gaining importance for rock and soil grouting over the last few years. One of the more dramatic technical innovations in the grouting industry that has been sought is the ability to mill, on-site, a fine or ultrafine cement-based grout using regular cement, and locally available additives (fly-ash, pumice, slag, bentonite, clay, tailings, catalysts, sand). This paper presents the results of extensive research and testing program executed during the development of a mobile Particle Size Reduction Mill (PASREM). The search for an inexpensive and effective milling machine for on-site production of ultrafine cement-based suspension grout has been ongoing since the early 1990's. The application of on-site milling would solve the problems associated with the use of classic pre-prepared ultrafine cement. This includes the agglomeration of particles that often results in a grout with a higher average particle size than desired, reducing penetrability of the grout, and the high cost of ultrafine cement. On-site milling would also allow for the use of many locally available products and additives that could enhance the final grout and reduce the cost of producing the grout. PASREM is a mobile milling machine used to produce ultra fine cements from readily available portland cements and additives. This process is preferably done by injecting a balanced cement-based suspension grout through the PASREM, immediately prior to grouting. This is further referred to as the wet milling process. The PASREM process can also be used to mill the aforementioned dry powders to microfine size, to produce a classic (bagged) microfine cement. Alex Naudts "Irreversible changes in the grouting industry caused by polyurethane grouting: An overview of 30 years of polyurethane grouting"
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Alex Naudts
Abstract Alex Naudts, Eric Landry, Stephen Hooey, and Ward Naudts "Additives and Admixtures in Cement-based Grouts"
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Alex Naudts and Rudy Van Impe.
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Alex Naudts and Doug Heenan.
Abstract Eric Landry, Daniel Lees and Alex Naudts. "New Developments in Rock and Soil Grouting: Design and Evaluation." Geotechnical News. September 2000. Pp. 38 - 44. AbstractThere are two major components in a soil grouting operation. The first step is the design of a site-specific grouting program. The second step is the execution of that program; this includes on site monitoring and assessment of the operation in real time. If these tasks are undertaken with state-of-the-art engineering methods, then the best achievable results will be predictably accomplished. Two recent developments are discussed in this paper; the first, an In situ Soil Injection Simulator (I.S.I.S.), developed for use during the design phase of a soil grouting program and the second, a Computer Aided Grouting Evaluation System (CAGESTM), developed for utilization during the execution phase of a soil or rock grouting program. The In situ Soil Injection Simulator (I.S.I.S.) was developed to assist during the design phase of soil grouting programs by improving on the present methods of determining and predicting the injectability limits of a given grout into a specific soil. The ISIS test cell was constructed with sufficiently large dimensions to reduce the effect of "boundary conditions" that distort the results of typical injectability tests. The soil in question is reconstructed by matching the soil gradation (sieve curves), silt content, moisture content, overburden pressure, density etc existing in the field. These reconstructed soils are injected with different grout types and/or formulations to determine the injectability, lateral grout spread, residual permeability (both horizontally and vertically), and grouted soil strengths for each grout type. Alternatively, different soil layers can be constructed to resemble a variety of conditions to test the performance of the various grouts in different field conditions. This type of laboratory test can be instrumental in determining the type of grouts and spacing of the grout holes and for predicting the characteristics of the grouted soils. Without the ISIS, these parameters are often determined by applying 'theories', mathematical models and 'rules of thumb with variable degrees of success. Additional technical Papers and articlesAlex Naudts, Eric Landry, Stephen Hooey, and Ward Naudts"Additives and Admixtures in Cement-based Grouts" Grouting and Ground Treatment Conference hosted by the Deep Foundation Institute and the Geoinstitute of the ASCE New Orleans, February 10-12, 2003. Pp. 1180-1191.
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Hot bitumen grouting technology has continually evolved since its early applications almost a century ago in France, Germany and the USA to seal persistent leaks in tunnels, below dams and for erosion protection along canals. Advancements in the industry especially in the field of monitoring and grouting equipment has made the injection of hot bitumen in conjunction with cement based suspension grout, the most economical, practical and sure solution to stop major inflows through, below or around structures. These applications proved the effectiveness of the hot bitumen grouting technique to stop major water inflows and stabilize water bearing, cohesionless soils, in a fast, predictable and economical way. This paper elaborates on a few remarkable field applications, one of which was likely the largest grouting effort ever undertaken. Alex Naudts "Irreversible Changes in the Grouting Industry Caused by Polyurethane Grouting: An overview of 30 years of polyurethane grouting" Grouting and Ground Treatment Conference hosted by the Deep Foundation Institute and the Geoinstitute of the ASCE New Orleans, February 10-12, 2003. Pp. 1266-1280. Abstract Water reactive polyurethane grouts were introduced into the grouting industry during the late sixties by the Takenaka company in Japan under the trade name TACSS. It became possible to inject "one component" grouts without potlife that do not easily wash out and react with the ground water. Because of environmental scrutiny, the first series of TACCS were replaced by solvent-free, hydrophobic, MDI based polyurethane prepolymers. Whilst remarkable successes were booked in mining and geotechnical engineering projects, more and more these products were used for permanent seepage control for sealing concrete structures. Hydrophilic polyurethanes were also introduced in Japan predominantly for the latter application. They contained solvents and were TDI based. Their high reactivity and high dilution ratio with water made them attractive to practitioners. In 1980, the N.V. DeNeef Chemie obtained the exclusive rights for TACSS for most places on earth and the successes in stopping major leaks in tunnels changed classic grouting (sodium silicate cement combinations) and seepage control grouting (acrylamide grouting) because of practical and environmental considerations. After the N.V. Denys brought similar products to the industry in 1980, more manufacturers jumped on the bandwagon. By the mid-eighties there were more than 10 manufacturers of polyurethane grouts. Several new and improved hydrophobic water reactive urethanes were developed during the eighties as a result of this new trend. A few manufacturers created closed cell, water reactive hydrophobic polyurethanes. The era of custom-made formulations, tailored to the project, started. Water reactive hydrophilic polyurethanes came under close scrutiny because of longevity problems. The classic two-component polyurethane foams, used in mining were gradually introduced in geotechnical engineering. For permanent seepage control, in concrete structures two-component polyurethane elastomers became popular. The introduction of hydro-block in France for major inflow control was another remarkable development. Extensive research was performed, especially in Scandinavia to establish life time expectancy of hydrophobic water reactive polyurethane. Pioneering research was done to establish mathematical models to understand the flow of P.U. through fine fissures. This paper focuses on the engineering aspects of polyurethane grouting with in the background the history of these fascinating products. It elaborates on the various types of applications illustrated with case histories for each type. Alex Naudts and Eric Landry "New On-site Wet Milling Technology for the Preparation of Ultrafine Cement-based Grouts" Grouting and Ground Treatment Conference hosted by the Deep Foundation Institute and the Geoinstitute of the ASCE New Orleans, February 10-12, 2003. Pp. 1200-1220. Abstract The use of ultrafine cement-based grout has been gaining importance for rock and soil grouting over the last few years. One of the more dramatic technical innovations in the grouting industry that has been sought is the ability to mill, on-site, a fine or ultrafine cement-based grout using regular cement, and locally available additives (fly-ash, pumice, slag, bentonite, clay, tailings, catalysts, sand). This paper presents the results of extensive research and testing program executed during the development of a mobile Particle Size Reduction Mill (PASREM). The search for an inexpensive and effective milling machine for on-site production of ultrafine cement-based suspension grout has been ongoing since the early 1990's. The application of on-site milling would solve the problems associated with the use of classic pre-prepared ultrafine cement. This includes the agglomeration of particles that often results in a grout with a higher average particle size than desired, reducing penetrability of the grout, and the high cost of ultrafine cement. On-site milling would also allow for the use of many locally available products and additives that could enhance the final grout and reduce the cost of producing the grout. PASREM is a mobile milling machine used to produce ultra fine cements from readily available portland cements and additives. This process is preferably done by injecting a balanced cement-based suspension grout through the PASREM, immediately prior to grouting. This is further referred to as the wet milling process. The PASREM process can also be used to mill the aforementioned dry powders to microfine size, to produce a classic (bagged) microfine cement. Alex Naudts and Doug Heenan "Construction Techniques: Grouting the ABC Way. The use of an advanced grouting program at Penn Forest Dam results in reduced construction costs and high quality products." International Water Power and Dam Construction March 2000. Pp. 32-35. Alex Naudts and Luigi Narduzzo "Restoration of Rideau Locks: Grouting technology improves structure" Concrete International March 1994. Alex Naudts and Murray Yates "New On-site Wet Milling Technology for the Preparation of Ultrafine Cement-based Grout" Canadian Geotechnical Society Conference. Montreal, Canada. October, 2002. Alex Naudts, Donald Bruce, and Glen Smoak "High Flow Reduction in Major Structures: Materials, Principals, and Case Histories" Grouts and Grouting. Proceedings: Geo-Congress 98. Boston, MA. pp. 156-175. 1998 Eric Landry, Daniel Lees, and Alex Naudts "New developments in rock and soil grouting: design and evaluation" Dam Engineering. Vol. XI, Issue 2. July 2000. Pp. 111 - 129 Abstract There are two major components in a soil grouting operation. The first step is the design of a site specific grouting programme. The second step is the execution of that program - this includes on-site monitoring and assessment of the operation in real-time. If these tasks are undertaken with state-of-the-art engineering methods, then the best achievable results will be predictably accomplished. Two recent developments are discussed in this paper: first, an in situ soil injection simulator. Alex Naudts and Walter Van Veen "Installation of a Grout Curtain as a Permanent Cut-off Wall" Second International Grouting Conference. Toronto, May 29-30, 1990. Abstract This paper describes the use of grouting technology to mitigate an unrestricted flow of water into an excavation for a high rise development in Metropolitan Toronto. The site is located on the shores of Lake Ontario in a fill deposit largely comprised of silty to clayey soil with occasional sand beds. The excavation was near to completion, to a point 0.9 metres below lake level, when at its nearest point to the lake (30 metres) a layer of highly permeable brick rubble producing an uncontrollable flow of water was encountered. The area was dyked and pumped, but when no measurable change in water level was observed, it was concluded that there was probably a direct link between the lake and the excavation through the brick rubble. A number of permanent control systems were considered including dewatering, tanking the building, sheet piles, and a slurry trench. However, based on time and economic considerations a grout curtain was found to be the most suitable system. The grout curtain was installed by means of a sleeve pipe injection system. The rubble and loose fill was grouted with stable bentonite/cement grouts with varying composition. A lower silt infilled rubble zone was injected with microfine cement. Following completion of the grout curtain, the flow was reduced to approximately 100 litres per minute which was considered controllable with a standard perimeter and underfloor drainage system. Alex Naudts "Enhancing the performance and bearing capacity of in-situ cast piles by base grouting some theoretical and practical considerations." Second International Grouting Conference. Toronto, May 29-30, 1990. Edward Des Rochers, Bruce McKinstry and Alex Naudts. "Flood protection for a deep gypsum mine." Second International Grouting Conference. Toronto, May 29-30, 1990. Alex Naudts "Grouting to Rehabilitate historical canals: Contemporary European Practice." International Conference on historical canals. Chaffeys Locks, September 1990. Alex Naudts "Curtain grouting from 900 metre deep donut shaped tunnel to dry-up leaking shaft at IMCs K2 Mine." Conference on soil and rock improvement. Milano, Italy. March 18-20, 1991 John Long and Alex Naudts "In-situ encapsulation of low radioactive nuclear waste using state-of-the-art permeation grouting techniques" International contaminant technology conference. St. Petersburg, Florida. February, 1997. Alex Naudts "Hot Bitumen Grouting:The antidote for catastrophic tunnel inflows." Tunneling Association of Canada (TAC) News June 2002. Pp 2-4. Alex Naudts "New developments in grouting technologies" Conference: Grouting practices in geotechnical engineering Milwaukee, Wisconsin. November, 19-20, 1990. Dale D. Huff, John D. Long, and Alex Naudts "Radwaste source control by surgical strike - a cost effective strategy" Radwaste November 1996. Pp.20-26. Site design and hosting by PairoWoodies |
