Karst bedrock conditions and deterioration of the lock and dam structures have resulted in significant leakage through, underneath, and around Lock and Dam No. 8 on the Kentucky River. During severe droughts, the water surface in Pool No. 8 has been observed to drop below the crest of the dam, resulting in water supply shortages and water quality issues for surrounding communities reliant on the pool. Presently, the primary purpose of Lock and Dam No. 8 is water supply. Pool No. 8 is currently where the cities of Nicholasville (Jessamine County, KY) and Lancaster (Garrard County, KY) draw their water. Due to the age and condition of the structures, and the criticality of the retained water supply, the project Owner commissioned a replacement dam to be built. One major component of the replacement dam was a foundation improvement program. The foundation improvement program was designed to address the karst bedrock conditions at the site. The foundation improvements included a secant pile cutoff wall and a double-row grout curtain. The grout curtain at Lock and Dam No. 8 was evaluated based on the metrics presently available.

When hollow concrete masonry is used for construction in high seismic regions, structural designs typically require fully grouted walls. The grouting process is labor-intensive, time-consuming and has a high energy demand due to requirements of consolidation in each and subsequent grout lifts. Self-consolidating grout with admixtures has been successfully used without segregation in walls of up to 12.67 ft. in height. Investigation of self-consolidating grout mixes without admixtures has potential for sustainability improvement. This thesis reports on the compression strength and consolidation observations of self-consolidating characteristics of no vibration/no admixture grout made by substituting various proportions of Portland cement with Type F fly ash and/or ground granulated blast furnace slag (GGBFS). The percentages of Portland cement replacement evaluated were 0%, 50%, 60%, and 70% for Type F fly ash. The percentages of Portland cement replacement evaluated were 0%, 60%, 70% and 80% for Type F fly ash and GGBFS. Grout compressive strengths were evaluated from individually filled grout specimens constructed in concrete masonry hollow core units, dry cured, and tested after 7, 14, 28, 42, 56, and 130 days. Also, hollow concrete masonry walls were built 12.67 ft. tall and grouted. The relative performance was assessed by comparing to conventional grouted masonry and evaluating consolidation characteristics around mortar fins and reinforcement; compressive strength tests after 130 days of curing, and rebar pull-out tests were taken from various wall heights. All experimental grouts had acceptable consolidation characteristics but fly ash replacement grouts did not meet the compressive strength requirements.

There are over 602,000 bridges in the United States, of which 12.5% are classified as functionally obsolete and 11.2% are structurally deficient. The functionally obsolete bridges will require expansion or replacement to increase the service capacity of the bridge. The structurally deficient bridges will either need remediation of the load carrying elements which are damaged or deteriorated or will need to be replaced completely. Replacement of the bridges means new construction; new construction means better design and quality assurance to meet the 100+ year service life requirement in place now. Rehabilitation of bridges will require better design and quality assurance to increase the current service life of the structure. This dissertation presents new design, testing, and repair methods developed to extend the life of new and existing bridges through pressure grouting, thermal integrity testing of drilled shafts, and the bond enhancement of fiber reinforced polymer (FRP) repair materials bonded to concrete with vacuum bagging and pressure bagging, respectively. Pressure grouting of drilled shaft tips has been used for over five decades to improve the end bearing capacity, but no rational design procedure had ever been published until this study. The research outlined in this dissertation analyzed nine grouted shafts and compared them to standard design procedures to determine the improvement in end bearing. Improvements ranged from 60% to 709% increase in end bearing capacity. From these improvements, a design procedure was developed for pressure grouted drilled shafts. Post construction inspection of drilled shafts relies largely on non-visual techniques dealing with measured concrete quantities, acoustic wave speed or frequency, gamma radiation attenuation and now the internal temperature of the curing concrete. Thermal Integrity Profiling (TIP), developed at USF, utilizes the heat of hydration of curing concrete to evaluate the concrete cover, foundation shape, cage alignment, and concrete mix design performance. This research developed standard test equipment and procedures for thermal integrity testing. Comparing the results of the different types of integrity tests is difficult due to the varied nature of the different tests. The dissertation looked at various shafts constructed across the nation which were tested with thermal and at least one other integrity test method. When compared to acoustic and gamma radiation test results, TIP agreed with 4 of 6 cases for acoustic and 2 of 5 cases using gamma radiation. In the one case were both sonic caliper and inclination data were available, TIP showed good agreement. Vacuum bagging and pressure bagging are techniques for improving the FRP-concrete bond in the repair of partially submerged piles. Prototype vacuum bagging and pressure bagging systems were developed and bond improvement assessed from results of pullout tests on full size piles repaired under simulated tidal exposures in the laboratory. Pressure bagging gave better bond and was found to be simpler because it did not require an airtight seal. A field demonstration project was conducted in which pressure bagging was used in combination with two different glass FRP systems to repair two corroding piles supporting the Friendship Trails Bridge across Tampa Bay. Inspection of the post-cured wrap showed no evidence of air voids.

Grouting as a method of strengthening and sealing rock, soil and concrete is widely used. The possibilities of sealing structures are of great importance from both an economical and environmental point of view. The cost of grouting has in certain projects been as high as the cost for the blasting and excavation of the tunnel. To improve the technique of grouting with cement based material, it is necessary to focus on the properties of the used grout mixture. The ability of a grout to penetrate cavities, channels and porous material, the penetrability, depends on two things, the theology and the filtration tendency. Extensive laboratory tests on stable, low w/c-ratio, injection grouts show that the most significant limitation to their penetrability is the tendency of cement grains to agglomerate into an impermeable filter cake. The properties of a grout that may prevent passing obstructions in the flow path without the cement grains clogging and preventing further penetration is in this work called filtration tendency. An inert material mixture and a cement-based mixture are used for the investigations in this work. The inert material, which is crushed dolomite stone, does not react with the added water in the mixture. The used cement grouts are based upon three types of commercial available Portland cements and four Portland cements with modified grain size distribution curves. Performed tests show that the grain size and grain size distribution is of great importance for the filtration tendency. According to performed experiments with inert and cement material, it seems to be advantageous for the penetrability to have a grain size distribution that contains neither too many fine or coarse grains. It is reasonable to believe that the grain size distribution should be relatively steep (narrow grain size range) between minimum and maximum grain size. The maximum grain size is of importance in terms of for example d95. Too large maximum grain size will prevent penetration of the mixture through obstructions in the flow path. According to performed tests, the value of d95, should be between 4-10 times smaller than the aperture to be penetrated by the cement based mixture. The small grain sizes are also of importance in order to achieve a low filtration tendency of the grout. This is because of the increased tendency for the small grains to flocculation into larger agglomerates, compared to larger grain sizes. The filtration experiments with cement based grouts show that influences of parameters like surface chemistry (use of superplastisisers) and cement chemistry (hydration of cement grains) will strongly affect the filtration tendency of the mixture. To visualize the phenomenon of filtration tendency it can be investigated on a larger scale than usually takes place. Filtration experiments in the scale of approximately 100:1 have been performed in order to see influences of grain concentration, grain shape and the penetrated slot aperture. It can be seen that used grain sizes (monodisperse and inert mixture) should be approximately at least 2-3 times smaller than the aperture to be penetrated by the mixture. Numerical experiments of filtration tendency have also been performed to investigate the possibilities to numerically simulate the influence of grain concentration and slot aperture. The numerical experiments are based on Eulerian flow modelling. / QC 20101007

The rheological properties of cement based grouts change with water/cement ratio and time, during the course of hydration. For this reason, it is desirable to be able to measure this change continuously, in-line, with a robust instrument during the entire grouting operation in the field. The rheological properties of commonly used cement grouts were determined using the Ultrasound Velocity Profiling combined with the Pressure Difference (UVP+PD) method. A non-model approach was used that directly provides the properties, and the results were compared with the properties obtained using the Bingham and Herschel-Bulkley rheological models. The results show that it is possible to determine the rheological properties, as well as variations with concentration and time, with this method. The UVP+PD method has been found to be an effective measuring device for velocity profile visualization, volumetric flow determination and the characteristics of the grout pump used. / <p>QS 2013</p>

Published scientific work indicates that residential large diameter drinking water wells are at a higher risk of contamination from surface water impacts than drilled wells. The possibility of a higher incidence of contamination of large diameter wells is attributed to site selection and construction problems such as leaking joints in the well casing, ineffective annular sealant placed between the well casing and the formation, a poorly fitted cover with an access lid that promotes contaminant entry and air entry without adequate air filtration, well location down gradient of septic effluent sources, and depth limitations due to improper equipment used to advance the well which results in shallow wells often situated in topographical lows. In some situations, flaws in the well design were actually deliberate measures intended to capture surface water at sites with low groundwater yield. Historically, residential drinking water well performance studies have focussed on existing wells; however, uncertainty in the actual well construction methods and materials, well age and maintenance efforts have been problematic. A field and laboratory study was completed to assess the performance of several design changes that were thought to improve the integrity of large diameter drinking water wells, and to determine whether one design is more prone to atmospheric and/or surface water contamination than the other. Four large diameter residential wells were installed at a study site in Lindsay, Ontario. Three of these wells are constructed with enhanced construction methods (two using a cement tile casing and one using a galvanized steel casing) and annular sealants, while the fourth was constructed using conventional methods for cement cased wells. The enhanced test wells utilized a sealant between the casing sections, various annular sealants between the formation and the well casing, sanitary waterline connections, and ventilation with air filtration. The well constructed using outdated methods did not have any of these advanced features. An automated water extraction system removed about 875 L/day from each well to mimic residential usage. Routine monitoring, and laboratory and field testing were used to collect pertinent data required for this performance assessment. Routine monitoring involved the visual inspection of the wells, collection of well water elevation, collection of soil temperature profile data, collection and analysis of water samples, and collection of cumulative water volumes purged from the test wells. A biofilm cleaning study and analysis of cement-bentonite grout was conducted in the laboratory while smoke and aqueous tracer tests were conducted in the field. The biofilm cleaning study entailed growing a biofilm on different large diameter well casing materials and applying cleaning methods thought to be practical for cleaning the interior walls of large diameter wells. Different mixtures of cement-bentonite grout were subjected to volume measurements, vertical load bearing capacity analysis, and hydraulic conductivity analysis to determine their suitability as a potential annular sealant. The tracer tests were developed to determine whether pathways for either airborne contaminants or surface water to enter the test wells exist. The test wells were filled with smoke and monitored for potential atmospheric pathways. A tracer solution was infiltrated around the test wells and the interior of the tests wells were monitored for potential pathways for surface water to enter. Bacteriological indicators were detected in all test wells. The smoke tracer tests demonstrated that pathways for airborne contaminants to enter the test wells exist with more pathways observed in the winter than the summer. The aqueous tracer tests highlighted several areas where surface water could enter the test wells if ponding occurred around the well casing. As expected the enhanced test wells performed much better than the conventional test well for both of these tracer tests. The results of the biofilm cleaning study indicated that galvanized steel or fibreglass casing materials were the only materials able to be cleaned effectively. The best method in this study to remove biofilm from casing materials was pressure washing. The results from the cement-bentonite grout investigation indicated that cement-bentonite grout with 5% bentonite would make the most suitable annular sealant as its volume changed the least during curing, it was strong enough to support the load from maintenance efforts, and was the most impervious. The results of this study indicate that large diameter wells constructed with a proper annular sealant, sealant between casing sections and a sanitary waterline connection are less prone to contamination. Monitoring of the test wells should continue as they mature to determine whether this plays a significant role in their ability to prevent contamination of large diameter wells. Smoke tracer tests should be conducted again during the winter to determine if temperature was the cause of increased atmospheric pathways. A field-scale method to remove biofilm from the interior casing wall of large diameter wells should be developed and tested. A field-scale investigation of cement-bentonite grout for use as an annular sealant should be completed. Fibreglass casings can be fabricated as a continuous piece with no seams or joints and hence another well should be constructed and studied using corrugated fibreglass (NSF ANSI 61) casing.

Published scientific work indicates that residential large diameter drinking water wells are at a higher risk of contamination from surface water impacts than drilled wells. The possibility of a higher incidence of contamination of large diameter wells is attributed to site selection and construction problems such as leaking joints in the well casing, ineffective annular sealant placed between the well casing and the formation, a poorly fitted cover with an access lid that promotes contaminant entry and air entry without adequate air filtration, well location down gradient of septic effluent sources, and depth limitations due to improper equipment used to advance the well which results in shallow wells often situated in topographical lows. In some situations, flaws in the well design were actually deliberate measures intended to capture surface water at sites with low groundwater yield. Historically, residential drinking water well performance studies have focussed on existing wells; however, uncertainty in the actual well construction methods and materials, well age and maintenance efforts have been problematic. A field and laboratory study was completed to assess the performance of several design changes that were thought to improve the integrity of large diameter drinking water wells, and to determine whether one design is more prone to atmospheric and/or surface water contamination than the other. Four large diameter residential wells were installed at a study site in Lindsay, Ontario. Three of these wells are constructed with enhanced construction methods (two using a cement tile casing and one using a galvanized steel casing) and annular sealants, while the fourth was constructed using conventional methods for cement cased wells. The enhanced test wells utilized a sealant between the casing sections, various annular sealants between the formation and the well casing, sanitary waterline connections, and ventilation with air filtration. The well constructed using outdated methods did not have any of these advanced features. An automated water extraction system removed about 875 L/day from each well to mimic residential usage. Routine monitoring, and laboratory and field testing were used to collect pertinent data required for this performance assessment. Routine monitoring involved the visual inspection of the wells, collection of well water elevation, collection of soil temperature profile data, collection and analysis of water samples, and collection of cumulative water volumes purged from the test wells. A biofilm cleaning study and analysis of cement-bentonite grout was conducted in the laboratory while smoke and aqueous tracer tests were conducted in the field. The biofilm cleaning study entailed growing a biofilm on different large diameter well casing materials and applying cleaning methods thought to be practical for cleaning the interior walls of large diameter wells. Different mixtures of cement-bentonite grout were subjected to volume measurements, vertical load bearing capacity analysis, and hydraulic conductivity analysis to determine their suitability as a potential annular sealant. The tracer tests were developed to determine whether pathways for either airborne contaminants or surface water to enter the test wells exist. The test wells were filled with smoke and monitored for potential atmospheric pathways. A tracer solution was infiltrated around the test wells and the interior of the tests wells were monitored for potential pathways for surface water to enter. Bacteriological indicators were detected in all test wells. The smoke tracer tests demonstrated that pathways for airborne contaminants to enter the test wells exist with more pathways observed in the winter than the summer. The aqueous tracer tests highlighted several areas where surface water could enter the test wells if ponding occurred around the well casing. As expected the enhanced test wells performed much better than the conventional test well for both of these tracer tests. The results of the biofilm cleaning study indicated that galvanized steel or fibreglass casing materials were the only materials able to be cleaned effectively. The best method in this study to remove biofilm from casing materials was pressure washing. The results from the cement-bentonite grout investigation indicated that cement-bentonite grout with 5% bentonite would make the most suitable annular sealant as its volume changed the least during curing, it was strong enough to support the load from maintenance efforts, and was the most impervious. The results of this study indicate that large diameter wells constructed with a proper annular sealant, sealant between casing sections and a sanitary waterline connection are less prone to contamination. Monitoring of the test wells should continue as they mature to determine whether this plays a significant role in their ability to prevent contamination of large diameter wells. Smoke tracer tests should be conducted again during the winter to determine if temperature was the cause of increased atmospheric pathways. A field-scale method to remove biofilm from the interior casing wall of large diameter wells should be developed and tested. A field-scale investigation of cement-bentonite grout for use as an annular sealant should be completed. Fibreglass casings can be fabricated as a continuous piece with no seams or joints and hence another well should be constructed and studied using corrugated fibreglass (NSF ANSI 61) casing.

Design of autoclaved aerated concrete (AAC) masonry in the United States is currently based on Appendix A of the 2008 Masonry Standards Joint Committee (MSJC) Code. Those provisions include the design of lap splices, and equations for the nominal capacity in interface shear transfer between grout and AAC. The provisions for lap splices are an extension of the provisions for concrete or clay masonry, modified to neglect the contribution of AAC to splice capacity. This thesis describes a testing program aimed at verifying the current provisions using tests of lap splices in grouted AAC masonry. Based on the results of those tests, the provisions are shown to be appropriate. The provisions on interface shear transfer between grout and AAC require that the transferred shear be checked against a nominal capacity based on limited test results. This thesis describes a testing program aimed at verifying and refining this nominal capacity using pullout tests of grout cores in AAC masonry units. Based on the results of those tests, the currently used nominal capacity is shown to be conservative, and a recommendation is made to increase it. / text

In the past decade, the grouting industry has made significant technological advancements in real-time monitoring of flow rate and pressure of pumped grout, stable grout mix design, and with grout curtain concepts dealing with placement and orientation. While these practices have resulted in improved construction practices in the grouting industry, current design guidelines for grout curtains are still predominately based on qualitative measures such as engineering judgment and experience or are based on proprietary methods. This research focused on the development of quantitative guidelines to evaluate the effectiveness of a grout curtain in porous media using piezometric and hydraulic flow data. In this study, a laboratory-scale physical seepage model was developed to aid in the understanding and development methodology to evaluate the effectiveness of a grout curtain. A new performance parameter was developed based on a normalization scheme that utilized the area of the grout curtain and the area of the improved media. The normalization scheme combined with model-based Lugeon values that correspond to pore pressure and flow rate measurements at different soil unit weights and grout curtain spacings, produced a mathematical equation that can be used to quantify the effectiveness of a grout curtain. This study found a relationship that takes into account soil unit weight, grout curtain spacing and a new performance parameter that can be used to help predict the effectiveness of a grout curtain.

Grouting techniques have been in used for many years, but several new grout materials have surfaced in recent decades that have re-defined the boundaries of the limitations of grouting programs. Typically these applications are used for seepage control in earthen impoundments, but strength of these earthen impoundments should be considered where there is potential for movement in the grouted soil mass. This study investigated initial conditions that could affect grout application effectiveness. The initial conditions in question were soil grain size and in situ moisture content. Two grouts were used, ultrafine and acrylate, and variations in pure grout properties were studied. An apparatus was developed so that a uniform grout could penetrate the pore spaces of a soil specimen. The rate of penetration of the grout into the soil was studied. The unconfined compressive strength of the resulting grouted soil was then analyzed. In testing neat ultrafine grout, it was shown that increased water-to-cement ratios had negative effects on the stability of the grout. Increasing the water-to-cement ratio from 0.5 to 2.5 resulted in a decrease in strength by a factor of 100. An inhibitor chemical was used to increase the time for reaction in the acrylate grout. During the chemical reaction, the curing temperature and gel times were monitored. A grout mix was selected for the acrylate grout that achieved appropriate gel times. In general, this study found that the grout penetrations rates into the soil increased as the initial moisture was increased from dry conditions to a gravimetric moisture content of nine percent. In each study, increased initial moisture decreased the grouted soil strength, with decreases in strength exceeding 50 percent. Empirical relationships were realized when compared to the initial matric suction of the soil. This suggests initial matric suction may be a useful initial condition for estimating increases in soil strength upon implementation of a grouting program for both the acrylate and ultrafine grouts.