Types Of Grout Research Articles

Influence of injection grout type on the load bearing capacity of stone masonry walls

Injektiranje je jedan od najdjelotvornijih, a cesto i najprikladnijih postupaka za pojacanje zidova starih zidanih građevina. Da bi se ocijenio utjecaj raznih vrsta injekcijskih smjesa na mehanicka svojstva zidanih građevina, obavljeno je ispitivanje in situ postojece zidane građevine. Dobiveni rezultati koristeni su za ocjenu seizmicke otpornosti građevine pomocu metode postupnog guranja, uz primjenu pristupa katnog mehanizma i mehanizma globalnog odziva. Prihvatljivije vrste injekcijskih smjesa usporedive su s cementnim injekcijskim smjesama. Dobiveno je da se pristupom globalnog odziva postižu realniji rezultati cak i kod niskih zidanih građevina

Evaluation of the Performance of Grouting Materials for Saturated Riprap.

In this study, four types of grout were developed to evaluate the effect of grouting of saturated riprap layers on ground water flow. The developed types of grout are divided into a quick-setting type and a general-type, and also into high and low viscosities. A number of grout tests were performed in a model acrylic chamber, 0.4 m in diameter and 2.0 m in length, for visual observation of injection. To reproduce the field flow condition of the saturated riprap layers (approach flow), the grout tests were carried out at 0 cm/s and 100 cm/s for the flow speed and 10 L/min for the grout injection speed after installing a flow injection opening on the lower part of the chamber. Based on the results of the grout tests, the injection of each grout in the saturated riprap layers was examined to find out the most effective grout.

Geotechnical Engineering Assessment of the Nargesi Damsite, Southwest Iran

This paper describes the results of the engineering geological investigations and geotechnical studies performed in the Nargesi dam site. The dam foundation located on the sedimentary rocks of Neogen period. To conduct this study, the steps including field and laboratory investigations, surface discontinuity surveying, drilled borehole data, and permeability were performed on dam foundation. Besides, the evaluation of the dam foundation was carried out by water pressure tests, which indicate the necessity of creating a grout curtain below the dam foundation. The permeability and groutability characteristics of the Nargesi dam foundation are significantly affected by geology of the site. The rock mass properties of the test section obtained from secondary permeability index (SPI) completed with the degree of jointing of the drill core acts as a useful reference for ground treatment design. Here, the performed laboratory tests were as: determination of density, moisture percent, porosity percent, water absorption, uniaxial compressive strength, Point-load strength index (Is50), p-wave velocity (Cp), s-wave velocity (Cs), deformability, and triaxial tests. The rock mass properties and classifications of the damsite is assessed using rock mass rating, the rock quality (Q), and the geological strength index classification systems. The strength and modulus elasticity of rock masses were determined through the equations proposed by different researchers. According to the findings of this work, except for some cases, there is a reasonable correlation between SPI and rock quality designation values. Based on these results, grout type and composition was suggested for the design of grout curtain.

A performance study of high-strength microbial mortar produced by low pressure grouting for the reinforcement of deteriorated masonry structures

Abstract Microbial grouting reinforcement to repair the deterioration of masonry structures involves injecting microorganisms and nutrient solution (a cementation solution) into existing granular system pores to induce the generated calcium carbonate cementation to form a microbial mortar of certain strength. Microbial grouting reinforcement is used when traditional grouting materials, such as lime, cement and epoxy, cannot be employed. In this paper, based on experimental study, the main biochemical factors that affect microbial mortar strength were investigated. In addition, the mixture ratio and laboratory preparation method for high-strength microbial mortars were determined. Microbial mortars of different strengths were successfully produced, through which the maximum uniaxial compressive strength reached 55 MPa. The mechanical properties of the microbial mortar, such as uniaxial compressive strength, splitting tensile strength, compressive strength under cyclic loading and uniaxial compressive fatigue, were tested, and the crystal structure of the carbonate cementation and pore-size distribution of the microbial mortar were analyzed. The results indicate that in strength, deformation and durability, this new material is superior to conventional cement–lime mortar. This new type of grouting is ideal for the in situ reinforcement of deteriorated masonry structures. The preparation method for high-strength microbial mortar, the material’s tested mechanical properties and the quantitative relationships of the material’s grouting parameters are reported. The material provides a novel method to reinforce deteriorated masonry structures, particularly historical masonry structures.

Proportioning of Cement-Based Grout for Sealing Fractured Rock-Use of Packing Models

Fractured, very permeable rock hosting repositories for radioactive waste will require grouting. New grout types of possible use where long-term performance is needed should have a small amount of cement for minimizing the increase in porosity that will follow from the ultimate dissolution and erosion of this component. They have to be low-viscous and gain strength early after injection and packing theory can assist designers in selecting suitable proportions of various grout components. Optimum particle packing means that the porosity is at minimum and that the amount of cement paste needed to fill the voids between aggregate particles is very small. Low porosity and microstructural stability must be guaranteed for long periods of time. Organic additives for reaching high fluidity cannot be used since they can give off colloids that carry released radionuclides and talc can be an alternative superplasticizer. Low-pH cement reacts with talc to give high strength with time while Portland cement gives early but limited strengthening. The clay mineral palygorskite can be used for early gelation because of its thixotropic properties. Once forced into the rock fractures or channels in soil it stiffens and serves as a filter that prevents fine particles to migrate through it be lost. However, its hydrophilic potential is too high to give the grout a high density and high strength. According to the experiments carried out, most of the investigated grouts are injectable in fractures with apertures down to 100 μm.

In situ tests and seismic assessment of a stone-masonry building

The injection of grout into multi-leaf stone masonry walls with a sufficient amount of voids can be an effective technique for the seismic strengthening of such walls. In order to evaluate the effectiveness of different types of commercial grouts that fulfilled the adopted criteria, the stone masonry walls of an actual building were strengthened by means of grout injection, using cement and combined cement–lime grouts. The quality and effectiveness of grout injection technique was assessed by non-destructive tests (sonic and radar tests), minor destructive tests (surface and in-depth probing and coring, and the double flat jack test), and destructive test (shear-compressive test), all in situ. Preliminary laboratory tests were also performed on mortar and stone specimens, on the injection grouts, and on cylinders representing the inner core of the strengthened walls. Finally, the seismic resistance of the building was evaluated in non-strengthened and strengthened variants (i.e. after grout injection of the walls with cement or lime–cement grout) by means of non-linear static analysis, using the pushover method. Obtained results show that shear characteristics of the walls (tensile strength and stiffness) depend significantly on the type and properties of the injected grout, i.e. on the grout’s ability to achieve a solid bond between the stones and the leaves including the properties (strength and stiffness) of the grout itself. In the case of the type of masonry under consideration, an adequate level of seismic resistance can be achieved also by using combined cement–lime grouts, although cement grout can provide higher seismic resistance.

Filtration and penetrability of cement-based grout: Study performed with a short slot

Filtration of cement-based grout during penetration through fractures in rock is an important issue while sealing the rock around tunnels. Whether a type of grout could be designed to penetrate a fracture of a certain aperture without filtration is an interesting question that needs to be further investigated. This study examines the question of whether grout penetration can be measured using our designed measuring method as well as which factors and processes influence the penetrability and filtration of the grout. The penetration and filtration of grout are complex processes influenced by many factors such as the grain-size curve of the cement, hydration and flocculation, pressure, grain concentration, and the geometry of constriction. The measured results were in agreement with the predicted results, indicating that the filtration process in the given geometry describes correctly.

Assessment of the long-term stability of cementitious barriers of radioactive waste repositories by using digital-image-based microstructure generation and reactive transport modelling

Cement-based grout plays a significant role in the design and performance of nuclear waste repositories: used correctly, it can enhance their safety. However, the high water-to-binder ratios, which are required to meet the desired workability and injection ability at early age, lead to high porosity that may affect the durability of this material and undermine its long-term geochemical performance. In this paper, a new methodology is presented in order to help the process of mix design which best meets the compromise between these two conflicting requirements. It involves the combined use of the computer programs CEMHYD3D for the generation of digital-image-based microstructures and CrunchFlow, for the reactive transport calculations affecting the materials so simulated. This approach is exemplified with two grout types, namely, the so-called Standard mix 5/5, used in the upper parts of the structure, and the “low-pH” P308B, to be injected at higher depths. The results of the digital reconstruction of the mineralogical composition of the hardened paste are entirely logical, as the microstructures display high degrees of hydration, large porosities and low or nil contents of aluminium compounds. Diffusion of solutes in the pore solution was considered to be the dominant transport process. A single scenario was studied for both mix designs and their performances were compared. The reactive transport model adequately reproduces the process of decalcification of the C–S–H and the precipitation of calcite, which is corroborated by empirical observations. It was found that the evolution of the deterioration process is sensitive to the chemical composition of groundwater, its effects being more severe when grout is set under continuous exposure to poorly mineralized groundwater. Results obtained appear to indicate that a correct conceptualization of the problem was accomplished and support the assumption that, in absence of more reliable empirical data, it might constitute a useful tool to estimate the durability of cement-based structures.

Mechanical characteristics of Asphalt-Cement Concrete foundations (ACC).

Asphalt Cement Concrete (ACC) is a new material. On the basis of Kuhn’s paradigm, conventional methods which are proper for similar road pavement materials were applied for studying the ACC. ACC is obtained from cold mixing technology such ingredients as cement-sand mortar or cement-mineral aggregate mortar, or cement-sand-mineral aggregate mortar with recycled Asphalt Concrete (AC) mixture or with recycled Mastic Asphalt (MA) mixture. Quick setting cement (CEM I 52,5 NA) is used in all mentioned cases. Novelty of the presented material is due to existence of two internal bounds - flexibility and rigidity. Such ACC parameters as stiffness, deformability and strength in general depend on type and characteristics of cementitions grout which coats applied recycled asphalt materials and fills mixture’s air voids. ACC layer stability may be predicted using viscoelastic model parameters of constitutive relations, including Burgers model, under steady and slow loadings, finally expressed by exponential formulae. This is the research study. Its basic part consists of laboratory and field testing and obtained tests results analysis. Further, road pavements were designed with subbase of ACC with improved performance comparing to typical materials.

Comparison of Creep Behaviour and Fatigue Behaviour of Grouted Sand

An experimental study aimed at comparing of creep and fatigue behaviour of grouted sand is presented. Unconfined creep tests and cyclic tests were performed to highlight the creep and the fatigue behaviour of Fontainebleau sand grouted with three types of grout: a silicate grout, a micro-fine cement-based grout and a mineral-based grout. Creep and fatigue results were compared in terms of strain rate, creep slope or fatigue slope, and creep limit strength or fatigue limit strength. Some analogies were observed between the creep and the fatigue behaviours. These behaviours can be compared from a qualitative point of view, since creep and fatigue curves have the same shape (both showing primary and tertiary behaviour), and from a quantitative point of view, under certain loading conditions.

Field and laboratory performance of bridge columns repaired with wrapped glass-fibre-reinforced-polymer sheets

Several bridge columns, in which concrete was delaminated as a result of steel corrosion, were repaired in the mid 1990s. Different types of grout, including one based on expansive cement, were used to rebuild the damaged columns to their original shape; the columns were then wrapped with glass-fibre-reinforced polymers (GFRPs). The associated lab study indicated that the observed damage caused a reduction of about 20% in the axial-load-carrying capacity of the columns and much larger reductions in ductility and energy-dissipating capacity. The experimental results also showed that the strength and ductility of the columns could be recovered by repairing them with GFRP. Long-term monitoring of three columns repaired in the field using GFRP has indicated their excellent performance. No deterioration has been observed in the fibre-reinforced polymer or in the columns in more than 10 years. Monitoring has also shown a reduction in the rate and associated risk of corrosion over time; thus, this is a more durable retrofitting technique than traditional ones, such as steel jacketing.Key words: concrete, columns, corrosion, cyclic loading, ductility, expansive cement, glass-fibre-reinforced polymers, monitoring, repair, strength.

Tunneling under compressed air through immersed soft soil strata

The paper presents the problems encountered at the building of main sewer from Braila town, driven with shield under compressed air. The sewer tunnel is built in very difficult conditions: - the shield is driven through immersed silty sands strata and under loessial strata sensitive at humectation; - the sewer trace pass under an urban area (streets, buildings etc.) at variable depth (6 - 8m) and with settlements restrictions; - the hydrostatic level varies along the tunnel from 2m above at 2m below the upper level of shield. The main features of this work are presented: - The shield used (De = 4.15m) of open type with manual digging; - The strength structure of tunnel made of two lining, a primary precasted (six bolted segments of 20cm thick) and a secondary cast in place (25cm thick) and the type of grouting; - Air compressed production and storage equipment and air locks which have been located at the start of tunnel; - The problems and difficulties encountered during the latest 230m of tunnel (compressed air loss, surface settlements, the measures for breaking in final shaft). (A) This paper was presented at Safety in the underground space - Proceedings of the ITA-AITES 2006 World Tunnel Congress and the 32nd ITA General Assembly, Seoul, Korea, 22-27 April 2006. For the covering abstract see ITRD E129148. Reprinted with permission from Elsevier.

Behavior of Horizontal Shear Connections for Full-Depth Precast Concrete Bridge Decks on Prestressed I-Girders

This article reports on a study of the horizontal shear resistance of the connection between full-depth precast concrete bridge deck panels and prestressed concrete girders. This connection consists of isolated shear connectors extending from the precast I-girder into a block-out pocket in the precast deck panel. The blockouts and the haunch between the panel and the beam are grouted. In the study, 36 push-off tests were performed to investigate the strength and behavior of the connections. The factors investigated included type of grout, haunch height, and area of reinforcing steel crossing the interface. In addition, several alternate shear connector details were tested. Results showed that there was no significant difference in peak shear stress between specimens with 1, 2, and 3 in. haunch heights. The extended stirrups must be detailed to have a minimum of 5 in. embedment into the deck panel. The alternate shear connectors in this study are viable for use with the precast panel system. Proper embedment and spacing of connectors will ensure yielding of the steel and ductile behavior of the interface. The authors conclude that, of currently known horizontal shear resistance equations, the one presented in the AASHTO LRFD Bridge Design Specifications is the best predictor of the strength of the specimens.

Shear modulus and damping ratio of grouted sand

An experimental comparative study of three different grouted sands in terms of their effects on the values of two dynamic properties is presented. The dynamic properties studied are the shear modulus and the damping ratio which are determined with resonant column tests and cyclic triaxial tests. The behaviour of a pure Fontainebleau sand is compared with the behaviour of a Fontainebleau sand grouted with a silicate grout, a micro-fine cement grout and a mineral grout. The effects of the grouting treatment, the type of grout, the confining pressure, and the strains, on the shear modulus and the damping ratio are studied. The test results have shown that grouting improves the stiffness of the sand especially for small strains. Whatever the type of material, confining stress improves the shear modulus whereas it has a negligible effect on the damping ratio. When strain increases, the shear modulus decreases and the damping ratio increases.

Comparaison des comportements au fluage et à la fatigue du sable injecté

ABSTRACT This paper describes unconfined creep tests and cyclic tests performed to characterise creep behaviour and fatigue behaviour of Fontainebleau sand grouted with three types of grout, a silicate grout, a micro-fine cement-based grout and a mineral-based grout. Results are compared in terms of strain rate, creep slope or fatigue slope, and creep limit strength or fatigue limit strength. These tests make it possible to show some analogies between creep behaviour and fatigue behaviour on the one hand from a qualitative point of view since creep curves and fatigue curves have the same shape with the presence in both cases of primary and tertiary behaviours and on the other hand from a quantitative point of view under certain loading conditions.

Materials behaviour and process characteristics in the removal of industrial cement tile grout using a 1.5 kW diode laser

Decontamination and reuse of tiled surfaces have always been costly activities. This paper describes an investigation into the feasibility of removing cement based grout between commercial tiles using a 1.5 kW high power diode laser (HPDL). It is known that it is very difficult to remove this type of grout conventionally. This investigation involves a single pass laser scan to remove the grout to 3 mm in depth. This paper presents relationships between the laser processing conditions and the material behaviour such as physical changes, thermal profiles after laser treatment and effect of laser processing on the ceramic tiles. A model, based on thermal mapping, was applied to the grout removal process to predict the temperature profiles within the material during the laser treatment.

Module de cisaillement et coefficient d'amortissement du sable injecté

ABSTRACT Resonant column and cyclic triaxial tests are performed on Fontainebleau sand grouted with three different types of grout, a silicate grout, a cement-based grout and a mineral based-grout in order to determine two parameters characterizing soil behaviour: shear modulus and damping ratio. Effect of grouting, type of grout, confining pressure, and strain is studied. Grouting improves stiffness of material especially for small strains. Whatever the type of material, confining pressure improved shear modulus whereas it has a negligible effect on the damping ratio. When strain increases, shear modulus decreases and damping ratio increases.

Pullout Bond Properties of Fiber-Reinforced Polymer Tendons to Grout

This paper presents the results of pullout bond tests on fiber-reinforced polymer (FRP) tendons embedded in cement mortar filled steel tubes. The pullout test program involved four types of FRP bars, three types of grouts, and two types of bond lengths. The experimental results have shown that the pullout behavior of grouted FRP tendons are influenced by the material properties and surface conditioning of the tendon. The bond length, surface geometry and manufacturing of the tendon, grout properties, and anchorage radial stiffness have an effect on the bond strength of the tendon to the grout. An analytical model of bond stress–slip relationships for grouted FRP tendons has been proposed, and its effectiveness to represent the entire bond-slip curve has been demonstrated.

Evaluation of Corrosion Protection for Internal Prestressing Tendons in Precast Segmental Bridges

A research program utilizing modified macrocell corrosion specimens was conducted to investigate corrosion protection for internal tendons in segmental bridges. Test variables were segmental joint type, duct type, joint precompression and grout type. Specimens were subjected to 4 years of exposure testing, after which selected specimens were removed for destructive examination. Dry joint specimens performed very poorly, as evidenced by corrosion currents measured during exposure testing and by tendon and duct corrosion observed upon destructive examination. Epoxy joints limited chloride penetration, preventing tendon corrosion and reducing duct corrosion. Plastic post-tensioning ducts performed very well, limiting strand corrosion to negligible levels. The research indicates that epoxy joints are required for the protection of internal tendons in aggressive environments, and that plastic post-tensioning ducts provide a significant improvement in tendon corrosion protection. Many of the conclusions and recommendations presented are not only specific to segmental construction but are applicable to all forms of internal, grouted post-tensioning tendons.

Factorial design modelling of mix proportion parameters of underwater composite cement grouts

Abstract There is an increasing need to identify the rheological properties of cement grout using a simple test to determine the fluidity, and other properties of underwater applications such as washout resistance and compressive strength. This paper reviews statistical models developed using a factorial design that was carried out to model the influence of key parameters on properties affecting the performance of underwater cement grout. Such responses of fluidity included minislump and flow time measured by Marsh cone, washout resistance, unit weight, and compressive strength. The models are valid for mixes with 0.35–0.55 water-to-binder ratio (W/B), 0.053–0.141% of antiwashout admixture (AWA), by mass of water, and 0.4–1.8% (dry extract) of superplasticizer (SP), by mass of binder. Two types of underwater grout were tested: the first one made with cement and the second one made with 20% of pulverised fuel ash (PFA) replacement, by mass of binder. Also presented are the derived models that enable the identification of underlying primary factors and their interactions that influence the modelled responses of underwater cement grout. Such parameters can be useful to reduce the test protocol needed for proportioning of underwater cement grout. This paper attempts also to demonstrate the usefulness of the models to better understand tradeoffs between parameters and compare the responses obtained from the various test methods that are highlighted.