High-strength Grout Research Articles

Effect of Fly Ash on Mechanical Properties of Polymer Resin Grout.

High-strength grout is specified to increase the bond between grout and bar in grouted connections and to ensure that the forces in the bars can be transferred to the surrounding material accordingly. Although polymer grout is fast setting and rapid in strength development, the use of polymer mortar in grouted connections is still limited because of the lack of information and familiarity practitioners have regarding the product. The goal of this work is to investigate the mechanical characteristics and performance of polyester grout containing fly ash that can be used as an infill material for grouted connections. This study focused on the composition of polymer grout, which typically consists of a binder, hardener, and filler. In this particular case, the binder was made of unsaturated polyester resin and hardener, while the filler was fine sand. The aim of the research was to investigate the potential benefits of incorporating fly ash as an additional filler in polymer resin grout and examine the mechanical properties of polymer resin grout. To this end, varying amounts of fly ash were added to the mix, ranging from 0% to 32% of the total filler by volume, with a fixed polymer content of 40%. The performance of the resulting grout was evaluated through flowability, compression, and splitting tensile tests. The results of the experiments showed that, at a fly ash volume of 28%, the combination of fine sand and fly ash led to an improvement in grout strength; specifically, at this volume of fly ash, the compressive and tensile strengths increased by 24.7% and 124%, respectively, compared to the control mix. However, beyond a fly ash volume of 28%, the mechanical properties of the grout started to deteriorate. Due its superior properties in terms of compressive and flexural strengths over all examined mixes, the PRG-40-28 mix is ideal for use in the infill material for mechanical connections.

A hybrid-sandwiching system for buckling-restraining of reduced beam sections

The present study proposes a new system for preventing local buckling in reduced beam sections (RBSs). The proposed method is called the “hybrid-sandwiching system”. In this approach, high-strength grout sandwiches an RBS part of a beam with the help of steel strips and high-strength bolts. Two T-shape specimens representing a beam-to-column connection were tested under displacement-controlled cycling loading. One specimen includes the conventional RBS and the other includes the proposed hybrid-sandwiched RBS. The experimental results of the specimens showed that the specimen with hybrid-sandwiched RBS experienced a considerable rotation up to a drift angle of R = 7% without any buckling in the web and flanges. However, in the specimen with conventional RBS, the flanges were buckled, and consequently, a significant strength degradation was observed at a drift angle of R = 4%. The experimental results confirmed that the hybrid-sandwiching system not only provides great ductility for RBSs but also does not disturb the basic role of the RBSs in moving the location of the flexural plastic hinges away from the columns' faces. In addition to experimental investigations, the finite element models (FEMs) of the specimens were conducted and validated with experimentally-obtained results. A series of FEMs was also carried out to verify the influence of hybrid-sandwiching systems on RBSs with different sizes.

Numerical model of cumulative damage evolution of offshore wind turbine grouted connection under cyclic axial load

GCs in OWTs are exposed to fatigue loads that can lead to damage of the grout before ultimate limit state is reached. A uniaxial and fatigue compression test of high strength grout material were carried out to obtain the compressive strength, failure mode, fatigue life and load-displacement relationship of test cubes. A uniaxial and fatigue tests were carried out on GCs specimens to study the damage evolution of the GCs. The fatigue test on GC was done by applying six incremental amplitude cyclic load ranges of 30%–80% of ultimate load on the GC. The scalar damage degradation parameter (SDEG) from the result of the numerical simulation was used to estimate a damage index which measured the cumulative damage evolution. The cumulative damage evolutions were influenced by the cyclic load amplitude. The larger the load amplitude, the higher the damage index accumulated. The numerical simulation results compared with the DNV code method showed that the DNV code predicted lower damage values for fatigue loads ratio of up to 0.725 and predicted higher damage values beyond the 0.725 loads ratio for the GC. The proposed numerical model predicted the laboratory test results of the grout cube and the grouted connections.

Frequency domain full waveform inversion with small‐scale laboratory measurements for reconnaissance in mechanized tunneling

AbstractIn mechanized tunneling, so‐called tunnel boring machines (TBMs) drill through the ground in an automatized manner. Therefore, the drilling process is very efficient but the maintenance costs are high. Seismic exploration seems appropriate to identify changing ground conditions in front of the TBM to reduce costs from damages of the TBM and from the corresponding dwell times. Today's seismic exploration techniques are using only a small amount of the information, which is contained in the seismic records from field observations, whereas full waveform inversion (FWI) tries to use the whole content. The potential of different FWI approaches for the application in mechanized tunneling has been investigated. An analysis of the performance of FWI not only employing synthetic examples but additionally measured waveforms is essential. Since seismic surveys at the construction side are not performed with FWI in mind, the data sets are usually not appropriate for testing the developed algorithms. Nevertheless, a validation of FWI approaches by measured waveforms is possible by using waveform recordings from a small‐scale experimental setup. A small‐scale super high strength grout specimen is constructed for validating an adjoint frequency domain FWI approach. Frequency domain models compute the seismic response of a system for an infinite time interval. The attenuation of the material as well as the attenuation effects at the free surfaces are hard to quantify over an infinite time interval. Therefore, the specimen is designed in a way that four of the six borders can be modeled as absorbing boundaries. For this purpose, the displacement recordings are truncated just before the waves that are reflected at the excluded borders arrive at the measurement points. This design in combination with a notch representing a rectangular tunnel makes the measurements more similar to data from a tunnel construction side. A rectangular hole is embedded in the specimen and acts as material discontinuity, which the FWI approach is aiming to detect.

Pull-out test of carbon-fiber composite cable (CFCC) tendon for an internal anchorage

An internal strengthening system involving the embedding of a post-tensioned prestressing tendon in a wedge-shaped anchorage of an existing concrete member was developed previously. The previous study confirmed the adequate load capacity of the prestressing tendon for the internal strengthening technique. The tendons used in the previous investigation were steel-rigid bar and steel-wire cables. These steel tendons are prone to corrosion under severe environmental conditions, such as bridge deck slabs sprayed with deicers. Carbon fiber composite cables (CFCC) are occasionally employed as tendons in prestressed concrete bridges. This study focused on the non-metallic material and examined the load capacity of CFCC tendon in internal strengthening systems to achieve the feasibility of the technique under corrosive environment. The main concern of the novel strengthening system was the anchoring system of the CFCC in the internal wedge. In general, both ends of the CFCC tendon can be gripped with external fasteners and be provided a tensile force using a hydraulic jack. In an internal prestressing system, a CFCC end must be anchored without any external fastener. It is preferable to simply fix the CFCC in a small wedge anchor made of existing concrete. This study focused on developing a CFCC anchoring method in a wedge-shaped hole and examined the tensile load capacity of the CFCC tendon fixed in the anchorage. The end of the CFCC tendon was reversely twisted to improve the pullout resistance by increasing the diameter of the cable. To examine the load-bearing capacity of the developed CFCC tendon, a mock-up reinforced concrete (RC) block with an internal wedge-shaped anchorage was used. A CFCC tendon equipped with a reverse-twisted tip was inserted into a wedge-shaped hole filled with high-strength grout. A pull-out test of the CFCC tendon was conducted to examine its load-bearing capacity. The test results revealed that the CFCC tendon with a reverse-twisted tip embedded in the anchorage exhibited adequate load-bearing capacity. This study confirmed that the post-tensioned prestressing system using the CFCC tendon is appropriate for strengthening RC members having the thickness of at least 200 mm, such as bridge deck slabs.

Seismic performance of repaired prefabricated shear walls

It is important to quickly strengthen and repair earthquake-damaged buildings to restore the normal life after earthquake. Therefore, it is necessary to study the seismic performance of widely-used assembled buildings repaired with different approaches. In this paper, two different methods are designed to repair seismically damaged shear walls assembled with grouted sleeves. Based on different damage scenarios, the first method uses high-strength grout to replace damaged concrete, and the second method uses grout jacketing with reinforcement implantation and reinforcing mesh to enhance the damaged cross-section. The repaired walls are compared with the original walls on the damage mode, bearing capacity, ductility, energy dissipation capacity, and stiffness degradation. The test results verify that both repair methods can restore the load-bearing capacity of the assembled shear walls. Further, the seismic performance of the two repaired seismic-damaged shear walls with different axial pressure ratios is analyzed using finite element analysis. The seismic loss indices of the original assembled and the repaired shear walls are calculated using the Park-Ang two-parameter seismic damage model based on the results of the experimental studies and the finite element analysis.

Flexural performance of hollow-core partially-encased composite beams

To conserve steel resources and reduce the weight of structural beams while ensuring sufficient load-bearing capacity and stiffness, a novel hollow-core partially-encased composite beam (HPEC) is proposed in this article. In this new composite beam, the foam formwork lies within the steel flanges, and high-strength cementitious grout is encased in the remaining space. Flexural experiments on four HPEC beams and two comparison specimens were conducted while considering the grouting strength, thickness, and shear stud arrangement in the beams. Typical flexural failure modes and crack patterns were observed, and the high-strength cementitious grout partially encased within the steel flanges improved the stiffness and flexural capacity. The welded studs delayed concrete cracking and improved the integrity of the composite beams. The flexural capacity of the HPEC beam was similar to that of the control specimen. However, the dead weight of the beam was reduced significantly, to only 43.33% of the control specimen. According to the elastic and plastic theories, the flexural capacities at yield load and peak load, respectively, were calculated; the computed results were consistent with the experimental findings, thus confirming that the analytical methods described herein can be applied to accurately predict flexural strength.

The Behaviour of Shear Anchors with Different Grout Properties

AbstractDuring the assembling of a steel structure with anchors, grout should be used in connections between steel elements and a reinforced concrete support element. In horizontal and vertical joints, grout is used as a good construction practice for solving geometric tolerance problems. Grout can be used with cast‐in anchors or post‐installed anchors. However, the relation between anchor shear resistance and characteristic grout compressive strength is not described in detail in technical regulations. The behaviour of a connection considering achieved slip tolerances should match the boundary conditions set in the global analysis. In the support joint, grout properties could influence the value of the slip between a steel part and a concrete part of the joint. Slip value could be significant for the relevant design cases featuring the interaction of shear force and tension force. In this paper, results of the push‐out test conducted on anchors are presented. Based on the experimental test, the finite element analysis was performed to investigate the shear connection behaviour. According to the preliminary results, it can be concluded that a grout strength and a grout thickness influence the connection response when serviceability loads are applied, although they do not influence the ultimate load bearing capacity of anchors. In some cases, using the contemporary solutions of high strength grout materials, the slip between steel and concrete parts in the connection could be reduced.

Experimental study on bond behavior between high-strength grout and deformed steel bars

Engineers use high-strength grout to connect precast concrete members for its low shrinkage and good fluidity. This paper designed 87 central pull-out specimens using the control variable method to investigate the influence of factors on the rebar-grout bond property such as compressive strength, steel grade, bar diameter, transverse stirrups, and bond length. The test result showed that improving grout compressive strength (85.8 MPa–122.7 MPa) cannot improve the bond strength, which was different from the previous conclusions of concrete pull-out tests. Simplified formulas were presented for calculating the characteristic values of bond strength, residual strength, peak slip, and relative slip of load-holding platform based on parameter analysis. Then, a constitutive model was proposed to predict the full-range bond stress-slip curve of high-strength grout and steel bar specimens from bearing to failure. Finally, FEA models were established to evaluate the applicability and accuracy of the constitutive model.

Experimental and numerical investigation of steel-grout-steel sandwich shells for wind turbine towers

Aiming at enhancing a wind turbine tower's performance while keeping its external diameter below transportability-imposed limits, a steel-grout-steel sandwich base segment comprising a high diameter-to-thickness ratio is investigated herein, as an alternative to plain steel towers. An experimental campaign was firstly carried out, involving downscaled tower specimens which comprise the above said cross-section under bending loads, followed by the development of an elaborate finite-element (FE) model which can accurately capture the experimental behavior in terms of strength, stiffness and failure mechanism. A full-scale version of the validated model, representing the bottom segment of a wind turbine tower under design loads, was finally employed for the conduction of a parametric analysis, as regards the structure's geometry and material properties, and the investigation of the sandwich concept's possible advantages over a conventional steel structure. Owing to the synergy between the steel tubes and the grout core, the composite specimens almost reached their plastic moment capacity, premature buckling was prevented, and ductility was preserved, despite the significantly high diameter-to-thickness ratio of the steel tubes and the thin grout core. Although performance deteriorates as the diameter-to-thickness ratio of the two steel tubes increases, the relative advantage of the sandwich tower over a plain steel one becomes more prominent, especially when high-strength grout is used. It is thus demonstrated that a sandwich-type shell comprising a thin layer of grout may improve a wind turbine tower's load capacity, stiffness and stability without increasing the total amount of steel, nor extending its base diameter beyond transportability-related restrictions.

Axial compressive behaviour of RC columns strengthened with rectangular steel tube and cementitious grout jackets

The welded steel tube and high-strength cementitious grout jacketing is a hybrid strengthening method for deficient reinforced concrete (RC) column without enlarging its entire cross-sectional area. This paper presents an experimental study on the performance of the welded steel tube and cementitious grout jacketing retrofitted RC (STGRRC) stub column under axial compression to figure out its strengthening effect. A total of eight STGRRC stub columns and one high-strength cementitious grout jacketing strengthened RC stub column are designed and analysed to investigate the effects of various parameters including the aspect ratio, the concrete cross-sectional area ratio (Ac/A) and the concrete strength. To better acknowledge the strengthening feature of the type of composite column, detailed discussions on the crucial indexes in terms of the confinement effect, the strength enhancement and the damage failure analysis are presented. The result reveals that the strength, stiffness and ductility of the original RC column could be highly improved by using this strengthening method. The axial compressive resistance of STGRRC stub column decreases with the increasing of aspect ratio and concrete cross-sectional area ratio. The ductility index value reduces with varying the aspect ratio and concrete strength in ascending order as well as the decreasing of concrete cross-sectional area ratio. To provide a basis for the future design and application, a simplified analysis method is proposed to predict the axial compressive resistance of the STGRRC stub column based on the limit equilibrium theory and verified well with experimental results.

Seismic behaviour of precast shear walls connected using prestressed horizontal beams

To facilitate construction and on-site quality testing, a new type of panel joint using cast-in-place connecting beams was developed and studied. The proposed connecting beams consist of overlapping vertical U-shaped steel bars stretching out of the wall and the footing, longitudinal prestressed steel strands, L-shaped steels and infilled high-strength grout. One monolithic shear wall specimen and five precast specimens were tested under simulated seismic loads. The test parameters studied included the presence or absence of L-shaped steel, sectional depths and the locations of connecting beams and locally non-bonded U-shaped steel bars. The effects of these parameters on the failure modes, hysteresis curves, stiffness, ductility and energy dissipation capacity were evaluated. The test results showed that the precast shear walls with the proposed panel joint achieved desirable seismic behaviour – comparable to or better than that of monolithic specimens – and can thus be safely applied in buildings in seismic zones. The use of L-shaped steel, prestressed steel strands and high-strength grout effectively delayed concrete crushing at the wall toes and thus improved the loading capacity, deformation capacity, initial stiffness, ductility and energy dissipation capacity of the precast shear walls.

Case Study: The Use of Concrete Prefabricated Prefinished Volumetric Construction for Two Blocks of 40-Storey Residential Flats (The Clement Canopy) in Singapore

The Singapore Building Construction Authority (BCA) is transforming its built environment sector into one that is advanced in technology to raise the productivity. The Design for Manufacturing and Assembly (DfMA) approach has been identified as a key strategy to raise the productivity in the construction industry. This paper outlines the pioneering approach of using reinforced concrete sandwiched composite shear wall system as the Prefinished-Prefabricated-Volumetric-Construction (PPVC) technology in construction of two residential towers of 40-storey high in <i>The Clement Canopy</i> project in Singapore. The technology involves a LEGO-like construction method by joining the PPVC modules of the same floor side-by-side; followed by modules of the upper level stacking on top of the completed modules below and the cycle repeated until completion. The gaps in between the adjoining modules’ walls were then filled with high-strength grout to connect them together such that the combined walls behave in a composite manner under loadings. Prototype tests had been carried out on the sandwiched wall panels with strain gauges installed to evaluate their behaviour under the actions of compression and bending. The test results showed that the sandwiched wall panels were able to withstand the loadings without delamination at the wall/grout interface, demonstrating that the designed sandwiched wall panel are able to behave in a composite manner under loadings. Installation of PPVC modules for the two towers was completed in approximately one year. The project achieved a manpower productivity data of 0.613 m²/man-day, a marked improvement of 72% in productivity as compared to the Singapore Year 2017 Industry Average Project Productivity Data for Residential (non-landed) figure of 0.357 m²/man-day. The project was successfully completed in Q1 of 2019 and is the tallest residential tower in the world at the time of project completion using the reinforced concrete PPVC technology. Advantages realised from the adoption of PPVC technology in this project includes improved productivity, early project completion; improved site safety, improved quality of end product and vast reduction in noise & dust pollution at the project site.

Eccentric compression tests and design of welded steel tube strengthened RC stub columns with high-strength grout

The post-welded steel tube and high-strength grouting material reinforcing method is a novel rehabilitation approach developed for RC structures with insufficient strength. It could significantly improve the strength without enlarging the original cross-section area. To figure out the mechanical performance of post-welded outer-wrapped steel tube and high-strength grouting material (HGM) strengthened RC (PSGS-RC) stub columns, this paper first reports on an experimental investigation. The influence of critical parameters such as the loading eccentricity and original core concrete area ratio on the behavior of this type of composite was analyzed in detail. The typical failure modes, vertical force versus axial displacement relationship, strain response, and ductility index of several crucial points are presented to better understand the mechanical performance of eccentrically loaded PSGS-PC short columns. Moreover, a detailed discussion on the strength enhancement index and concrete contribution ratio was conducted to figure out the typical feature of the novel rehabilitation method. Finally, for evaluating the resistance of eccentrically loaded PSGS-PC short columns, a design method based on the ultimate equilibrium theory was proposed. The result demonstrated that the typical failure modes of PSGS-PC short columns generally comprised the local buckling of outer-wrapped steel tube, tearing of weld, crushing of HGM and core concrete, shear failure of columns, and buckling of longitudinal rebar. The strength of eccentrically loaded PSGS-PC stub columns was enhanced with a decrease of the load eccentricity and the intrinsically core concrete column area ratio. The ductility property was significantly improved with an increase of the load eccentricity and the core concrete area ratio. This research is expected to provide a reliable design method for repairing structures that possess inadequate strength in engineering practice.

Fatigue deterioration mechanisms of high-strength grout in compression

Recent modern constructions such as wind turbines require improved performance of concrete and grout, while being submitted to continuous cyclic loading during their service life. The application of these materials can be in the foundations, towers and connecting joints in the transition piece in offshore and onshore structures. Therefore this paper is focussed on the compressive behaviour of a high-strength grout. For this purpose, the fatigue behaviour of the grout is quantitively analysed by considering different stress levels and frequencies of loading. The damage mechanisms are identified from analysis of strain development, temperature increase and stiffness evolution. The sources of temperature increase are identified and the resulting induced damage mechanisms are presented. The loading frequency has a significant influence on the deterioration process, demonstrated from strain development and evolution of the secant modulus. Analogies with the compressive fatigue behaviour of high-strength concrete can be carried out.

Compressive Strength Variability Limits of High-Strength Cementitious Grouts

Abstract The quality of grout becomes more important as many projects utilize precast concrete elements and systems to accelerate the delivery of a project. Also, the use of high-strength grout materials increases to properly connect high-strength concrete members. In the present study, two high-strength, cementitious grout materials were tested for their compressive strength to estimate a coefficient of variation (cv), to investigate effects due to curing condition and initial curing time, and to evaluate the strength ratio between cube and cylinder specimens. The 28-day strength of tested grouts reached more than 62.1 MPa (9,000 psi). The estimated cv was 2.3 %, which was slightly higher than the value of 2.1 % used in ASTM C109, Standard Test Method for Compressive Strength of Hydraulic Cement Mortars (Using 2-in. or [50 mm] Cube Specimens). Based on the estimated cv, the variability limits of compressive strength in ASTM C109 can be 9.5 % (from 8.7 %) for three cubes and 8.4 % (from 7.6 %) for two cubes. There was not a substantial difference in compressive strength between water-cured and moist-cured cubes. Also, the difference of compressive strength is minimal between cubes initially cured for 24 hours and 48 hours before demolding. The compressive strength ratio of ϕ100 mm × 200 mm cylinder specimens to 50 mm cube specimens was between 0.78 and 0.90 for different test ages. The mean ratio was 0.83. These observations can help engineers and practitioners to use ASTM C109 and ASTM C1107, Standard Specification for Packaged Dry, Hydraulic-Cement Grout (Nonshrink), with more confidence when they test high-strength, cementitious grout materials.

Failure analysis and design of grouted fibre-composite repair system for corroded steel pipes

Grouted fibre-reinforced composite stand-off sleeve repair is a light-weight and easily deployable repair system for steel pipelines with localised metal loss. The effectiveness of this type of repair system is dependent on the load transfer through the grout layer, which is weaker than neighbouring components and susceptible to failure due to stresses developed from applied internal pressure. In this study, three dimensional (3D) Finite Element Analyses (FEA) of a full-scale pipe with different levels of metal loss were implemented to evaluate the failure behaviour and capacity of grouted composite repair system. Steel pipes with a localised defect ranging from 20% to 80% metal loss and repaired using two infill grout systems reinforced with carbon and glass sleeves of different thicknesses were considered. The results indicated that the performance of the repair system is governed by the tensile cracking of the infill grout. A thicker sleeve and higher tensile strength grout delivers higher pipe capacity in the repair system. On the other hand, a high modulus grout provides a more effective load transfer from steel to sleeve. Using a high tensile strength grout, the composite repair system can restore the capacity of the steel pipe with defect up to about 70% metal loss.

Experimental study on seismic response of precast bridge piers with double-grouted sleeve connections

In recent years accelerated bridge construction (ABC) has become increasingly popular all over the world because of its good quality, cost effectiveness and decreasing bridge construction time. Much attention has been paid to substructure connections for ABC systems. Grouting sleeve (GS) is one of the most widely used connection methods. In this study, three 1/4 scale column models with two joints connected by different technique were conducted according to an actual precast bridge project. Two precast columns (B2, C2) were made to study the location effect of GS. One conventional cast-in-place (CIP) column (A2) was conducted as reference specimen. The seismic performance of the columns was investigated and compared. Experimental results showed that cracks for B2 with GS connectors in the column foot were less and plastic hinge had shifted to the ends of GS. The energy dissipation capacity of B2 was lower than that of reference specimen. Specimen C2 with GS connectors in the pier foundation appeared similar seismic performance to reference CIP A2, and the peak load of each cycle was higher due to the high-strength grout reinforced the interface bonding behavior between column and base. The displacement ductility coefficients for A2, B2 and C2 were 6.87, 5.14 and 6.42 respectively, and the GS connecting technique like B2 was not suggested for application in the high seismic area. The column-cap beam joint of all specimens remained intact throughout the testing from the strain results of the longitudinal bar.

Numerical modeling and parametric analysis of grouted connections under axial loading

Abstract With the rapid development of the offshore wind power industry, large-diameter grouted connections (GCs) with high-strength grout have become a developing trend. Previous studies on ordinary-strength and small-scale GCs may not meet current engineering needs. A numerical study was carried out to investigate how the axial mechanical properties of a large-diameter GC that has high-strength grout are influenced by geometric parameters, such as radial stiffness, the height to space ratio (h/s) of shear keys, and the length to diameter ratio (Lg/Dp). The finite element model was verified against the results of the experimental test. The mechanical properties of ultimate bearing capacity, interface transfer strength, ductility, nominal average stress and grout contact pressure distribution are discussed in detail. The results suggest that the increase in radial stiffness can strengthen the axial ultimate bearing capacity and ductility of the GC. Besides, the h/s of the shear keys can affect the ultimate bearing capacity and ductility of GC by influencing the number of diagonal compression struts. Although the Lg/Dp can significantly improve the axial ultimate bearing capacity of GCs, conversely, the interface transfer strength is continuously reduced. The research results can provide technical reference for the design of GCs in the offshore wind turbine industry.

Efficiency of geopolymer vs. high-strength grout as repairing material for reinforced cementitious elements

Geopolymer cementitious system represents an eco-friendly innovative construction material made without cement as a binder. Hence, the current study is devoted to investigate geopolymer’s characterization as repairing material for reinforced cementitious concrete elements in comparison with commercial high-strength grout. The adhesion performance of the geopolymer mortar using bonding agents based on styrene butadiene rubber (SBR) and epoxy resin were evaluated using slant shear test and pull-off test. In addition, the pull-out test was performed in order to evaluate the bond strength between steel reinforcing bars and different surrounding thicknesses of geopolymer mortar (GPM), namely; 3, 5, 11, 7.5, and 11.5 mm. Besides, the flexural performance of polypropylene fiber reinforced geopolymer mortar (FRGPM) was also evaluated. Moreover, the accelerated corrosion and half-cell potential tests were performed in order to investigate the effect of GPM thickness around steel reinforcing bars (2, 5, and 8.5 mm) as a corrosion protective layer. Test results showed that GPM had good bond strength to the cementitious concrete. In addition, epoxy resin-based bonding agent enabled the geopolymer repair mortar to achieve higher bond strength than that developed by SBR-based bonding agent. The results of rebar pull-out tests showed that using GPM mortar for anchorage of steel reinforcing bars should be implemented with minimum thickness of 5 mm in order to have sufficient bond strength. Moreover, the application of FRGPM as a tension layer enabled the repaired beam to outperform its flexural performance from the viewpoints of ultimate capacity, toughness and crack control. Furthermore, it was found that using GPM as corrosion protective layer of 2 mm thickness or more had the ability and efficiency to delay and control the chloride ions diffusivity.