Push-off Test Research Articles

Experimental Assessment of Shear Transfer Capacity of GFRP Reinforcement Using the Push-Off Test

Experimental Assessment of Shear Transfer Capacity of GFRP Reinforcement Using the Push-Off Test

The experimental and numerical simulation of interface shear behavior between ECC and coal gangue concrete

Composite concrete structures are designed to integrate various concrete types at different levels, thereby improving their shear properties. In this paper, the effects of the interfacial keyway, reinforcement ratio, and pouring sequence on the shear strength of concrete-coal gangue concrete interface are studied by experiments and analyses. A total of 10 specimens were made, and the push-off test was carried out. Nonlinear finite element simulation was carried out using ABAQUS, and the influence of keyway angle on crack development was studied based on the extended finite element method (XFEM). It is found that the remarkable tensile and crack stability of engineered cementitious composites (ECC) has a positive effect on the shear strength of the ECC-coal gangue concrete interface. The ultimate shear strength of the interface and the ductility of the interface under shear load are significantly improved by interfacial shear reinforcement. The introduction of an interfacial keyway improves the shear strength of the concrete interface, and the number of keyways has the most significant effect on the interfacial shear strength. The angle between the crack propagation direction and interface will increase with the increase of keyway angle, the simulation results are in good agreement with the experiments.

Shear Transfer in Concrete Joints with Non-Metallic Reinforcement

The use of non-metallic reinforcement can significantly reduce the carbon footprint of the construction sector. Mixed structures made out of steel and non-metallic reinforcement should be avoided due to the risk of galvanic corrosion. So far, researchers have been focusing on the load-bearing behavior in the longitudinal direction of the fibers. In this study, the behavior of the fibers in the non-metallic reinforcements is analyzed perpendicular to the fiber orientation. Therefore, a uniaxial shear test on a single bar (uniaxial shear test), as well as a series of push-off tests with reinforcements embedded in the concrete, was carried out. For both experiments, bars made of carbon fiber-reinforced polymers (CFRPs) and glass fiber-reinforced polymers (GFRPs) were investigated. In order to analyze the influence of non-metallic reinforcement in the joint, specimens without reinforcement have been tested as well. Also, the joint roughness and reinforcement ratio of the concrete joint was varied in the tests. The determined transverse shear strengths for the single bar exceed the values of the producer. For the push-off test, high standard deviations occurred, making it difficult to draw firm conclusions. Nevertheless, it is shown that increasing the amount of reinforcement leads to higher ultimate forces. The presented study emphasizes the necessity of further studies of the shear transfer in concrete joints.

Interfacial Shear Behavior of Composite Concrete Substrate to High-Performance Concrete Overly After Exposure to Elevated Temperature

Basically, the interface shear strength between two concrete layers of varying ages must be sufficient to withstand the applied actions on the structure, specifically fire attack, which may cause the complete collapse of the composite structure. Thus, interfacial shear behavior was investigated and analyzed in this paper under the influence of a set of parameters, including temperature (25, 200, 400, and 600 °C), time exposure (30, 60, 90, 120, and 180 min), concrete type, and fibers type (polypropylene fiber (PPF), steel fiber (SF), and hybrid fiber) by employing a Z-shape push-off test. The test consists of two parts with different ages: normal strength concrete (NCS) and high-performance concrete (HPC). HPC includes high-strength concrete (HSC) and fly ash concrete (FAC). Initially, twenty-five Z-shaped push-off tests were made, four of which were cast as one unit (NSC/or concrete with hybrid (FSP)), and the rest were composite specimens. Furthermore, a 3D finite element model of a composite push-off specimen was developed to simulate and analyze the impact of various time and temperature exposures on the interfacial shear strength of composite specimen N-FSP. The results indicated that temperature degree and exposure time adversely affected the interfacial shear strength. Also, interfacial shear strength is significantly influenced by fiber types. Including combined fiber (SF + PPF) improved the interfacial shear strength by 114% compared to the composite specimen NSC-NSC after exposure to a temperature of 600 °C. In contrast, using PPF negatively affected the interfacial shear strength, recording only 84% of the composite specimen NSC-NSC. In addition, the inclusion of supplementary cementitious material enhanced the interfacial shear strength by 60.5% in the NSC-FAC composite specimen with 30% FA, compared to the NSC-NSC specimen. Finally, a finite element (FE) model was proposed with a satisfactory level of accuracy (0.95 to 1.03) in predicting the maximum shear strength. Additionally, the difference between the FE and experimental stiffness was between 0.92 and 1.07.

A machine learning based method for predicting the shear strength of Fiber-Reinforced Concrete joints in precast segmental bridges

The utilization of Fiber-reinforced concrete (FRC) in the construction of Precast segmental concrete bridges (PSCBs) is progressively increasing. The design of joints among precast members can considerably impact the overall integrity and safety of the structure. Consequently, accurately estimating the shear capacities of FRC joints has become critical for evaluating the safety of PSCBs structures. However, the effectiveness and efficiency of formulas or models intended for prediction of the shear capacities of joints with normal concrete are unknown in predicting the shear capacities of FRC joints. In this study, the machine learning (ML) algorithms are employed to predict the ultimate load of FRC joints, utilizing a database of 192 push-off test results. Three individual models (Lasso, SVM, and KNN) and three ensemble models (RF, GBDT, and XGBoost) were developed for estimating the ultimate load. The GridSearchCV technique was utilized for parameter optimization based on the training set, in conjunction with a five-fold cross-validation method. A comparative study revealed that the XGBoost ensemble model surpassed other models, with a predictive performance ranking as follows: XGBoost > GBDT > RF > KNN > SVM > Lasso. The best-performing XGBoost model achieved performance metrics of R2 = 0.964, MAE = 41.318 kN, RMSE = 56.760 kN, and MAPE = 14.228%. The superior reliability of the XGBoost ensemble model was further validated through comparisons with current design codes and existing models. As ML-based models are typically black-box models, the SHapley Additive exPlanations (SHAP) method was employed to explicitly link the predicted output to the inputs. Based on SHAP results, confining stress (CS), depth of shear key (D), compressive strength of concrete (fcu), total height of joints (H), and height of flat part (Hsm) recognized as the crucial parameters affecting ultimate load.

In-depth analysis of the effect of physicochemical properties of ionic liquids on anti-icing behavior of silicon based-coatings

This study dissects the use of room temperature ionic liquids (RT-ILs) in a dynamic surface for anti-icing applications. Anti-icing properties of ILs-containing PDMS-based coatings fabricated by two different types of ILs, are evaluated to establish a relationship between the anti-icing behavior and physicochemical properties of the ILs. The surface chemistry of coatings and the existence of distinctive groups of the ILs anions on the surface of coatings characterized by Attenuated Total Reflectance-Fourier transform infrared (FTIR) spectroscopy (ATR-FTIR) and confirmed by using X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy-energy dispersive X-ray analysis (SEM/EDX). The 3D profiles and roughness parameter of the surfaces were investigated by a confocal laser microscopy profiler. Regarding the importance of correlation between wettability and ice adhesion, the wettability of coatings was studied. The results show a significant reduction 30–40% in sliding angle (SA) and contact angle hysteresis (CAH) in ILs-containing coatings. Differential scanning calorimetry (DSC), freezing delay time, push-off and centrifugal adhesion tests (CAT) served to distinguish the performance of the two ILs in regard to ice nucleation temperature and formation time, and ice adhesion strength, respectively. The 60–70% reduction in ice adhesion strength for the IL-containing coatings, obtained by push-off test, is due to the presence of strong ionic hydrogen bounded water and the formation of self-lubricating quasi liquid layer that can function at much lower temperature. Solid-state nuclear magnetic resonance (NMR) spectroscopy has confirmed the presence of nonfrozen water molecules at the interface. Consequently, incorporating ILs into coatings provides an effective approach to delay ice nucleation, restrict ice growth recrystallization and reduce ice adhesion strength. A comparison of enhanced anti-icing performance of ILs-containing coatings highlights the significant influence of minor changes in the chemical structure of ILs on their potential for anti-icing applications.

Analysis of two experimental setups to study mode II fracture on fibre-reinforced gypsum notched specimens

The main aim of this work is to study two relevant experimental setups designed for studying shear fracture and see if any of them allows studying the evolution of fracture under Mode II conditions, not only inducing a shear stress state at the onset of fracture. Two tests have been selected, a standardised test described by a Japanese standard, here referred to as the JSCE test, and the push-off test. These tests have been carried out on fibre-reinforced gypsum specimens with increasing proportions of polypropylene fibres and monitored by means of digital image correlation (DIC). The results show that fracture under Mode II conditions is relatively easy to induce with both tests, but once fracture begins, it is extremely difficult to induce a fracture process under Mode II. In general, Mode II has an important role at the onset on fracture, but Mode I predominates afterwards.

Shear Transfer Resistance with Different Interface Conditions: Evaluation of Design Provisions and Proposed Equation

The design provisions in current codes for shear resistance of concrete-to-concrete interfaces exhibit significant differences. In this study, the accuracy of design provisions for interface shear resistance was evaluated and compared. From the literature search, a database of 458 push-off test results of interface shear resistance was created to evaluate the shear transfer provisions from the ACI 318-19, PCI Design Handbook, AASHTO LRFD Bridge Design Specifications, CSA-S6, Eurocode 2, and Fib Model Code 2010. In addition, an equation was derived based on push-off test results collected from the literature to calculate the interface shear resistance for the monolithic uncracked interface. According to many analyses and evaluations of parameters affecting the interface shear resistance, the compressive strength of concrete played an important role, especially for the monolithic uncracked interface. Therefore, the compressive strength of concrete was included in the proposed equation to calculate the interface shear resistance in this study. It is expected that this equation can be applied more accurately than the existing design provisions when high-strength concrete is used. Statistical analyses were carried out for comparison with the existing design provisions to verify the applicability of the proposed equation. The results show that the proposed equation reasonably predicted the interface shear resistance for the monolithic uncracked interface. Appropriate conclusions were also drawn for the design provisions.

Investigating the fracture behavior of structural concrete shear key in prefabricated walls by discrete modeling

In this study, the cracking behavior of concrete-like materials in keyed shear joints of a structural member under the push-off test is investigated by employing discrete and continuum models. Initially, the behavior of the reinforced concrete member is simulated by a novel discrete element previously developed by the authors and referred to as the Rigid Body Coupled Spring model (RBCS). Shear key connections with different failure modes are modeled and compared to experimental observations. Following that, the numerical outcomes are discussed and compared with the outcome of Finite Element Method (FEM) models employing a continuum plasticity-based damage model. According to the obtained results, with the applied continuum method and constitutive model, unlike the experimental evidence, the modification of the shear key design did not have a significant effect on the failure mode of the modeled connection. On the other hand, the employed discrete element technique was able to represent the failure modes of the shear key connections. This study demonstrates the possibility of the application of discrete methods in studying the behavior of concrete in structural elements.

Experimental and numerical study on shear behavior of shear pockets between ultra-high-performance and normal concrete for precast girder bridges

Ultra-high-performance concrete (UHPC) has been widely utilized in precast bridge girders as a new material to reduce structural self-weight and improve constructional efficiency. Typically, UHPC and normal concrete (NC) are implemented to construct precast girders and deck, respectively, and cast-in-place shear pockets are used to connect these two. However, these shear pockets are vulnerable components that affect the integrity of UHPC-NC bridge superstructure. Thus, to comprehensively and deeply investigate the shear performance of shear pockets, a push-off test on block specimens and a bending test on a scaled bridge superstructure are conducted in this study. In addition, A refined finite element model (FEM) is proposed for UHPC-NC interface, which incorporates the effects of cohesion, dowel action of reinforcement and frictional force. The accuracy of the proposed FEM is validated against experimental data. Besides, the code equations are evaluated by push-off test results. The push-off test results verify that reinforcement across the interface plays a critical role in enhancing the shear strength between UHPC and NC, and NC is a weak region for the UHPC-NC interface, which should be paid much attention when designing. The experimental and numerical results of the bending specimen indicate that NC deck and UHPC girder connected by shear pockets with shear reinforcement can satisfy the performance requirements of a bridge girder, showing satisfactory integrity for UHPC and NC members under flexure. Furthermore, design equations specified in ACI318R-19, AASHTO, MC-10 and Eurocode 4 can provide a satisfactory prediction of shear strength at UHPC-NC interface, as demonstrated by comparing with experimental results.

Finite Element Investigation of Angle Ring Confinement for Clustered Large-size Stud Shear Connector in Full-Depth Precast Concrete Bridge Deck Panel

Full-Depth Precast Concrete (FDPC) bridge deck panel system, consisting of concrete deck and steel girders, has been used widely for highway and bridge construction due to rapid construction and replacement as well as in terms of economics. This system could integrate with clusters of large size headed-stud shear connectors for more significant connection, although larger composite actions were experienced. Therefore, a new angle steel ring confinement was introduced and tested by push-off samples for the most effective shear transfer. The Finite Element Analysis (FEA) of the push-off model with an in-depth investigation of non-linear concrete properties, boundary parameters, and different geometries of angle ring confinement was developed in this study. The FE models were verified with the push-off test in terms of loads, displacements, and failure stages. Nonlinear concrete material models: Concrete Damage (CD) and Drucker Prager (DP) were identified the different abilities either for predicting initial cracks, or determining maximum resistance and critical failure, respectively. The thickness of the angle and the sizes of hook bars were investigated for the most effective aspects of the angle ring confinement. The results showed comparable stiffness and load resistance for various aspects. However, compatible geometries, either 5 mm thick angles with DB12 hook bars or 10 mm angles with DB25 hook bars, were suggested. The final non-linear FEA model was reliable for comparative studies to FDPC push-off with different confinement configurations.

Experimental exploration of digitally fabricated connections for structural concrete

Connections are a persistent challenge for traditional reinforced concrete construction and even more for digital fabrication with concrete (DFC). The latter, on the other hand, opens up new possibilities for producing connections with tailored geometries and surface roughness. Based on the findings of an exploratory, experimental campaign, this paper discusses the design, fabrication and structural testing of digitally fabricated joints using the DFC technology Eggshell to 3D print the formwork for joint surfaces in an additive manufacturing process. The programme includes (i) unreinforced and reinforced construction joints whose joint surface texture was varied to control the roughness and (ii) digitally fabricated dry keyed joints with varying geometry. Both, the construction joints as well as the dry keyed joints, were produced using set-on-demand concrete with a relatively small maximum aggregate size of 0 to 4 mm – i.e., strictly speaking, mortar rather than concrete – as typically applied in DFC. The experimental campaign included thorough instrumentation: a 3D scan of the joint surface before testing and high-resolution digital image correlation (DIC) combined with distributed fibre optical sensing (DFOS) during testing. The deviations from the targeted surface geometry, determined with 3D scans, were below 2 mm, with a standard deviation between 0.4 mm and 0.7 mm for keyed joints. The high-resolution DIC allowed measuring the compressive strains locally at (i) the corrugation of unreinforced or reinforced construction joints and (ii) the key chamfer of dry joints and, hence, studying strain variations over the height of the joints and the efficiency of different keys with varying dimensions. Finally, the shear transfer capacity, evaluated in a push-off test setup, showed that all digitally fabricated joints met or even outperformed the requirements defined in pertinent design codes despite the smaller aggregate size.

Push-off test on concrete-concrete interface with different types of concrete after elevated temperatures

In this study, the post-fire shear strength of concrete-concrete interfaces after exposed to 20, 200, 400, and 600 °C was experimentally studied using Z-shape push-off tests. The influences of recycled aggregate concrete (RAC), high strength concrete (HSC), interface roughness, and cement mortar surface bonding agent were analyzed intensively. The test results indicated that the interfacial shear strength decreased significantly after exposed to elevated temperatures. The shear strength of the smooth interface decreased more rapidly than that of the rough interface. Under the condition of similar compressive strength, the interfacial shear strength of the specimen with RAC was not lower than that with natural aggregate concrete (NAC) and even demonstrated better fire performance. The employment of HSC contributes to the higher interfacial shear strength, but the deterioration is obvious after exposed to elevated temperatures. Based on the test results and variance analysis, this study also proposed preliminary interfacial shear strength degradation equations of the concrete-concrete interface after exposed to elevated temperatures, aiming to provide a reference for further numerical fire analysis.

Comparative Evaluation of the Shear Adhesion Strength of Ice on PTFE Solid Lubricant

The development of a durable and green icephobic coating plays a vital role in the aviation industry due to the adverse impact of ice formation on aircraft performance. The lack of study into how temperature and surface roughness impact icephobicity is the main problem with present icephobic coatings. This study aims to qualitatively evaluate the icephobicity performance of a polytetrafluoroethylene (PTFE) solid lubricant film, as an environmentally friendly solution, with a custom-built push-off test device in different icing conditions utilizing a wind tunnel. The ice-adhesion reduction factor (ARF) of the film has been assessed in comparison to a bare aluminium substrate (Al 6061). The impact of surface energy was investigated by comparing the water contact angle (WCA), the contact angle hysteresis (CAH), and the pull-off force of the PTFE solid lubricant and Al with an atomic force microscope (AFM). The results of ice shear adhesion on the PTFE solid lubricant film showed a significant reduction in the ice adhesion force at various substrate temperatures and surface roughness compared to the bare aluminium substrate. The difference in the ice adhesion between the solid lubricant and aluminium alloy was attributed to the differences in the detachment mechanism. For the PTFE-based solid lubricant, the interfacial detachment mechanism was based on the formation of interfacial blisters towards the centre of the ice. Consequently, upon continued application of the shear force, most of the energy injected would be distributed throughout the blisters, ultimately causing detachment. In the comparison of ice adhesion on PTFE solid lubricant and bare aluminium, the film showed minimal ice adhesion at −6 °C with an adhesion force of 40 N (ARF 3.41). For temperature ranges between −2 °C and −10 °C, the ice adhesion for bare aluminium was measured at roughly 150 N.

INTERFACIAL BOND STRENGTH BETWEEN MICRO-SYNTHETIC FIBER-REINFORCED PATCH REPAIR MORTAR AND CONCRETE SUBSTRATE BASED ON PUSH-OFF TEST

A micro synthetic fiber-reinforced mortar has been developed as a patch repair material. The bond strength of this material is a crucial parameter for successful repair applications. The state of stress occurring at the interfacial plane between the repair material and the concrete substrate influences the bond strength requirements of patch repair material. Therefore, bond strength envelope criteria should be established using, among others, the interfacial adhesion and friction coefficient parameters. This research aims to determine the composite’s interfacial bond strength parameters (adhesion and friction coefficient) between micro-synthetic fiber-reinforced patch repair mortar (MSFRPRM) and concrete substrate by push-off tests. At this stage, the smooth joint texture limits the investigation. The fiber volume fraction and age of repair are considered. The tests were conducted at the age of 1, 3, 7, and 28 days. In addition to the laboratory experiment, this research used ATENA Science GiD to numerically simulate the push-off test and study the influence of the fiber volume on the adhesion and friction coefficient. The results show that at a fiber volume of 0.06%, the adhesion and friction coefficients increase from 1.15 to 2.33 MPa and 0.74 to 0.85, respectively, corresponding to age. Numerical simulation indicates that the maximum adhesion and friction coefficient occurs at the fiber volume fraction of 0.06%. Thus, the overall simulation results can be used in the future as a parameter to establish MSFRPRM and concrete substrate bond strength envelopes that will be useful for evaluating the suitability of MSFRPRM as repair materials under various states of stress. Keywords: Bond Strength, Concrete Patch Repair, Concrete Substrate, Micro-Synthetic Fiber-Reinforced Repair Mortar, Push-Off Test DOI： https://doi.org/10.35741/issn.0258-2724.58.1.20

Repetitive behavior of an advanced demountable bolted shear connection in push-off tests

Currently, the repetitive behavior of the advanced bolted shear connector embedded in non-shrink self-compacting high strength pouring material (HPG) is unclear, restricting its application in steel–concrete composite beams (SCCBs). This study examined the repetitive performance of 21 push-off test specimens using different bolt diameters, bolt loads, loading paths, and loading programs. The failure models, load-slip response, shear bearing resistance, initial slip load, shear stiffness, peak slip, and ductility of this advanced bolted shear connection were evaluated. Bolt shearing off is the typical failure mode for all specimens, along with some concrete crushing underneath the bolts. Under repetitive loading, bolt shear capacity and load-slip response are similar to those under monotonous loading. Peak slip grows with the increase of bolt diameter under repetitive loading compared to monotonic loading. The shear stiffness under repetitive loading is lower than that under monotonic loading and improves with the bolt diameter and the bolt pretension increase. The ductility ratio under repetitive loading is smaller than that under monotonic loading and enlarges with the increase of the bolt diameter. Some design recommendations are proposed based on the existing formulae for predicting this advanced bolted shear connection.

Shear behavior of joints in precast UHPC segmental bridges under direct shear loading

The joints in precast ultra-high-performance concrete (UHPC) segmental bridges (PUSBs) play significant roles in the structural performance of PUSBs, which require systematic investigation to establish a thorough understanding of their shear behavior. To this end, the push-off tests for 11 UHPC joints, including 9 epoxy joints and 2 dry joints, were carried out to obtain the failure modes, crack distribution, and the load-relative vertical displacement relationships. The confining stress, number of shear keys, and joint types were the critical test parameters considered in this study. Experimental results show that the failure mode of flat epoxy joints was the spalling of the epoxy, and no visible damage was observed on the surface of joints. For the keyed epoxy joints, the brittle shear-off of shear keys led to the failure of joints. However, dry joint specimens showed severe damage and spalling of UHPC. The shear capacity of UHPC joints effectively improved as the confining stress and number of keys increased, and the epoxy joints exhibited a higher shear capacity than the dry joints. The shear strength formulas of UHPC joints were developed and the calculated results from the proposed formulas agreed well with the test results with an average ratio of 1.05 and a coefficient of variation of 0.079. Moreover, four calculation models for the UHPC joint shear strength were proposed based on the forms of existing shear strength formulas of UHPC joints and 61 push-off test results available in the previous studies were used to evaluate the calculation models.

Evaluation of self-consolidating concrete shear strength by means of push-off test

Self-consolidating concrete (SCC) can be characterised by its flowability, stability and passing ability. Although SCC tends to have a more uniform microstructure in the concrete–reinforcement interfacial transition zone, the reduction of the nominal size and coarse aggregate content in the concrete mix may adversely affect its shear strength. Therefore, the aim of this research was to evaluate the shear strength of SCC by means of push-off tests of 45 specimens, produced with one conventional concrete and two SCC mixtures, with two different coarse aggregate contents (reference and reduced by 30%). The transverse reinforcement ratio ranged from 0.46% to 2.28%, using closed stirrups crossing the shear plane. The increase of reinforcement ratio resulted in improvements in shear strength for specimens with one, two and three stirrups, while specimens with four and five stirrups had a premature failure owing to concrete crushing near the notch. No significant difference in shear strength was identified owing to concrete type or coarse aggregate. The experimental results were also compared with codes estimates, and Eurocode 2 presented the best fit to experimental results when compared with the American code ACI 318 and the Canadian standard CSA A23.3.

Experimental study on shear performance of an advanced bolted connection in steel-concrete composite beams

Compared to traditional shear keys, bolted shear connections adopted in steel-concrete composite beams or bridges provide the advantages of improved construction efficiency and rapid replacement of the deteriorated elements. However, current investigations on the shear performance of bolted shear connectors are quite limited. This paper explores the mechanical behavior of the advanced bolted shear connections embedded in steel and concrete composite beams. A total of 10 push-off test specimens were fabricated and carried out to determine the bolt diameter and the bolt pretension on the failure models, shear strength, initial slip load, shear stiffness, and peak slip of this advanced bolted shear connection. The experimental results demonstrate that bolt sheared off is the primary failure mode in all specimens with a small amount of concrete crushing underneath the bolts. Bolt pretension displays a negligible effect on the shear keys' failure models and the shear capacity, while the concrete spalling area increases as the bolt diameter improves. The initial slip load and the shear stiffness of the advanced bolted shear connections grow as the bolt pretension and bolt diameter increase. Based upon the existing formulae, some design recommendations are proposed for predicting this advanced bolted shear connection.

ESTUDIO DE LA INFLUENCIA DE LA ADICIÓN DE FIBRAS EN LA ROTURA EN MODO II DE MATERIALES CUASIFRÁGILES

Fracture of quasi-brittle materials, such as concrete or gypsum, has been studied for decades. These studies have given light on the fracture mechanisms as well as on the parameters that drive these processes, allowing producing numerical models that reproduce fracture using tools such as the Finite Element Analysis. On another note, the three possible Modes of fracture that can be identified in the field of Fracture Mechanics, Mode I is very well known, experimentally reproduced and used as the base for most numerical models. Nevertheless, in some cases fracture takes place as a combination of a stress state that induces a fracture mechanism where Modes I and II are involved. In this sense, Mode II fracture has been studied less often, partly because Mode I fracture is more usual, but also because reproducing Mode II experimentally is quite more complex. This study is focused on inducing Mode II fracture on fibre-reinforced gypsum specimens by using two different experimental tests. More specifically, the experimental test proposed by the Japanese standards JSCE and the push-off test are employed. The displacement field is obtained by means of the digital image correlation technique (DIC), which helps to understand how fibres modify the fracture mechanisms of the gypsum matrix when this takes place under Mode II conditions.