Single Fiber Pull-out Test Research Articles

Effect of moisture content on mechanical behavior of ultra-high toughness cementitious composites

This study presented an investigation into the basic mechanical properties of Ultra-high toughness cementitious composites (UHTCC) under varying moisture levels (0%, 56.5%, and 100%). UHTCC have been recognized for their excellent deformation and crack control abilities, making them ideal for repairing and reinforcing hydraulic structures. In this study, static compressive test and direct tensile test were conducted to determine the influence of free water on compressive strength, tensile stress and strain relationship, elastic modulus and energy absorption ability of UHTCC. Meanwhile, the notched beam fracture test and single fiber pull-out test were also performed to investigate the mechanism behind such phenomenon. The results of the study revealed that as the relative moisture content of UHTCC increased, the compressive and tensile strengths decreased to varying degrees. The softening effect of water on compressive strength of UHTCC was found to be more significant than that on its tensile strength. Furthermore, the direct tensile deformation capacity of UHTCC increased from 2.4% to 4.0% as the relative moisture content increased. Water infiltration into UHTCC was found to have a minimal effect on the number of tensile cracks but significantly increased their width. The results of notched beam fracture and fiber pull-out tests demonstrated that water infiltration led to a 30.4% decrease in matrix fracture toughness, a 37.3% decrease in chemical bonding strength, and a 23.4% decrease in frictional bonding strength between fibers and the matrix. The increased deformation ability of UHTCC in water environments was attributed to the increase in strain hardening energy index (Jb’/Jtip).

INGREDIENTS DEGRADATION IN STEEL FIBER REINFORCED CONCRETE AFTER THERMAL LOADING

The steel fiber reinforced concrete in structures provides good mechanical and physical characteristics and such material applications are increasing. At the same time, if structure is subjected to thermal load it is affecting both properties of reinforcement and matrix as well. The aim of the present research is to investigate the degradation of the characteristics of fibers, randomly distributed in the body of concrete block. A short steel fiber reinforced concrete slabs (400x300x18cm) [1], [2] with homogeneously distributed fibers was undergone to calefaction process from one side. dimension of 16.5x14.5x15 cm) Fiber fracture process was performed based on the single fiber pull-out test by preparing the specimens with fiber from calefacted SFRC block. Experimental curves from each layer were compared with different layer of fibers and investigation had shown that higher load-bearing capacity is there over the thermal loaded fiber. The conclusion were made with the microscopic results and the experimental data.

Rate-sensitive pullout resistance of smooth-steel fibers embedded in ultra-high-performance concrete containing nanoparticles

Single-fiber pullout tests for smooth-steel fibers embedded in ultra-high-performance concrete (UHPC) containing nanoparticles (NPs) were conducted at various pullout speeds (0.0167–500 mm/s). Three types of NPs, namely, nano-CaCO3, nano-SiO2, and nano-CNT, were added to UHPC at dosages between 1 and 3 wt % of cement. The addition of NPs to UHPC notably increased the rate sensitivity of fiber pullout resistance. Among the NPs, the addition of nano-CaCO3 (3 wt %) produced the highest rate sensitivities for the dynamic increase factors (DIFs) of both τeq (1.95) and τpeak (2.06), whereas UHPC without NPs obtained the lowest rate sensitivity of τeq (DIF = 1.18), and UHPC containing 3 wt % nano-CNT had the lowest rate sensitivity of τpeak (DIF = 1.62). Nanoindentation, scanning electron microscopy, and energy-dispersive X-ray spectroscopy tests revealed that the higher amount of C–S–H at the fiber–matrix zone produced higher pullout resistance and rate sensitivity.

Recycled carbon fibers in cement-based composites: Influence of epoxide matrix depolymerization degree on interfacial interactions

The use of recycled carbon fibers (rCFs) in cement composites is beneficial regarding strength improvements and environmental aspects. In this paper, we present the addition of carbon fibers recovered from reinforced epoxides using hydrogen peroxide (H2O2) to cement-based composites. Two degrees of depolymerization were investigated regarding the physiochemical properties of the fibers and the interfacial interactions. Although regained CFs exhibited a smaller amount of oxygen-containing groups on the surface than virgin CF (vCF), they exhibit better adhesion and pullout resistance, as proved in single-fiber pullout tests from a cementitious matrix. The subsequent incorporation of recovered CFs into cement-based composites resulted in a pronounced increase in flexural and compressive strengths compared with the plain matrices and the cement reinforced with virgin CFs. Furthermore, the rCFs with a higher degree of depolymerization showed a better interfacial interaction toward cement matrices and hence also a better reinforcing effect.

Influence of alkali treatment on the interfacial shear strength of Agave lechuguilla fiber and its significance as a reinforcing material in polymer composites for mechanical applications

AbstractThe aim of the research work was to fabricate the short Agave lechuguilla (AL) fiber‐reinforced epoxy composite and to improve its mechanical strengths. In order to do that, a single fiber pullout test was conducted to evaluate the critical length of the AL fiber and its interfacial shear strength (IFSS) in epoxy resin. To improve the IFSS, AL fibers were treated with varying concentrations (5%, 10%, and 15%) of NaOH, and it was found that 5% NaOH treatment exhibits excellent tensile strength and IFSS. Fibers treated with 5% NaOH and untreated fibers were used separately as reinforcement materials varying between 10% and 40% with a 10 wt% step in composites fabrication. The tensile strength, flexural strength, and modulus of the composites were evaluated as per ASTM standards. The results reveal that the composites reinforced with 30 wt% of untreated AL fibers give maximum tensile and flexural strength. When 5% NaOH‐treated fibers were used as reinforcement instead of untreated fibers, their tensile and flexural strength improved by 8.14% and 7.88%, respectively. To investigate the fracture mechanism of the tested samples, the specimen's fractured surfaces were analyzed using scanning electron microscope and reported in this paper.

Influence of Accelerated Aging on the Fiber-Matrix Adhesion of Regenerated Cellulose Fiber-Reinforced Bio-Polyamide

With regard to the sustainability and biological origin of plastic components, regenerated cellulose fiber (RCF)-reinforced polymers are expected to replace other composites in the future. For use under severe conditions, for example, as a housing in the engine compartment, the resistance of the composites and the impact on the fiber and fiber-matrix adhesion must be investigated. Composites of bio-polyamide with a reinforcement of 20 wt.% RCF were compounded using a twin-screw extruder. The test specimens were manufactured with an injection molding machine and aged under conditions of high humidity at 90% r. H, a high temperature of 70 °C, and water storage using a water temperature of 23 °C for 504 h. Mechanical tests, single-fiber tensile tests (SFTT), single-fibre pull-out tests (SFPT), and optical characterization revealed significant changes in the properties of the composites. The results of the SFPT show that accelerated aging had a significant effect on the bio-polymer and an even stronger effect on the fiber, as the single-fiber tensile strength decreased by 27.5%. Supplementary notched impact strength tests revealed a correlation of the impact strength and the accelerated aging of the RCF-reinforced composites. In addition, it could be verified that the tensile strength also decreased at about 37% due to the aging effect on the RCF and a lowered fiber-matrix adhesion. The largest aging impact was on the Young's modulus with a decrease of 45% due to the accelerated aging. In summary, the results show that the strengthening effect with 20 wt.% RCF was highly decreased subsequent to the accelerated aging due to hydrolysis and debonding because of the shrinkage and swelling of the matrix and fiber. These scientific findings are essential, as it is important to ensure that this bio-based material used in the automotive sector can withstand these stresses without severe degradation. This study provides information about the aging behavior of RCF-reinforced bio-based polyamide, which provides fundamental insights for future research.

Evaluation of workability, microstructure and mechanical properties of recycled powder geopolymer reinforced by waste hydrophilic basalt fiber

The recycled powder geopolymer (RPG) is an environmental-friendly cementitious material prepared from recycled powder (RP) recovered from construction waste. The preparation of geopolymers has promoted the development of sustainable materials, but the great brittleness limits the application scenarios. In this paper, the waste hydrophilic basalt fiber (WHBF) was used to reinforce RPG and the mechanical properties, toughness and microstructure were evaluated. The results indicated that the addition of WHBF significantly improved the compressive, flexural and tensile strength of the RPG. Adding 0.6% WHBF with 6 mm in length and 13 μm in diameter improved the compressive strength, flexural strength and tensile strength by 59.43%, 85.20% and 121.74% in 28 days, respectively, compared to the control group. The single fiber pull-out test and Digital Image Correlation (DIC) analysis indicated that the interfacial properties of the WHBF with appropriate geometric parameters were high and the direction and rate of crack growth were significantly changed, which greatly improved the toughness of the matrix. The analysis of water absorption and Mercury Intrusion Porosimetry (MIP) showed that although the incorporation of WHBF increased the porosity of RPG, the pore size was small and had no adverse effect on the matrix. The microstructure analysis showed that the addition of WHBF benefited the formation of additional gel, which provided a better bonding and frictional stress transfer path for the composites. Meanwhile, the energy absorption capacity of the composites was significantly improved and the crack propagation was inhibited. Furthermore, the WHBF enhanced the long-term drying shrinkage performance of RPG. This work suggested that the recycled powder geopolymer reinforced by waste hydrophilic basalt fiber shows excellent potential for application.

Experiments and prediction of direct tensile resistance of strain-hardening steel-fibre-reinforced concrete

The direct tensile resistance of strain-hardening steel-fibre-reinforced concrete (SHSFRC) was experimentally investigated and modelled. Three steel fibre types (twisted, hooked and smooth fibres) and three matrices with different compressive strengths (28 MPa (M1), 84 MPa (M2) and 180 MPa (M3)) were investigated in both single-fibre pull-out tests and direct tensile tests. A model based on machine learning was developed to predict the tensile resistance of the SHSFRCs. The experimental results showed that the twisted fibres not only exhibited the highest pull-out resistance but also the greatest tensile resistance in M1 and M2, whereas smooth fibres achieved the same results in M3. The predicted outcomes showed that the proposed model had high efficiency and accuracy in estimating the tensile resistance of SHSFRC, with a correlation coefficient of 0.951.

Strength analysis of carbon fiber reinforced PEEK composites with heat resistant sizing agents

Continuous Fiber Reinforced Thermoplastic Composites (CFRTPCs) are known for their demand in high-tech industries due to their excellent mechanical, thermal and chemical performance. However, poor adhesion interaction between carbon fiber (CF) and high-performance polymers such as PEEK tend to influence the mechanical modulus of the composite parts in a negative way. In the current work, a number of PAA-based sizing agents modified with various fillers were used for CF surface treatment in order to improve adhesion. Thus, the wettability of the sizing agents was studied, as well as the free surface energy using the Owens-Wendt method. The calculated energy values were used to determine the work of adhesion between the sizing agents and PEEK. The adhesive connection between the CF treated with the sizing agents and PEEK was examined by the single fiber pull-out testing. Furthermore, the most promising samples were used for CF, on the basis of which towpreg composites samples were obtained to study its physico-mechanical properties. Results suggested that the values of the strength characteristics of the composites are comparable to the values measured for composites based on commercially available materials.

An explicit methodology of random fibre modelling for FRC fracture using non-conforming meshes and cohesive interface elements

The failure mechanisms of fibre reinforced concrete (FRC) are complicated and governed by random phases at meso-scale, typically including fibres, mortar and fibre-mortar interfaces. This work develops an efficient numerical method using non-conforming meshes between the fibres and mortar. Their interfacial bond-slip behaviour is explicitly modelled by inserting zero-thickness cohesive interface elements between fibres and their replicas, i.e. the proposed “shadow fibres”. The shadow fibres are then constrained by the background mortar through a coupling technique proposed in the literature to ensure the displacement compatibility and force transmission. The damage and fracture of the mortar are captured by the concrete damage plasticity model, and the fibres are modelled by finite beam elements with elastoplastic constitutive relations. The proposed approach is validated by single fibre pullout tests, single fibre-bridged notched tension test-pieces, and direct tensile tests of ultra-high performance fibre reinforced concrete samples with random fibres. After comprehensive analyses of the key material and geometric parameters, the presented framework proves capable of capturing the major failure mechanisms at meso-scale, such as fibre pullout, bending and yielding, mortar cracking and spalling and fibre-mortar interfacial debonding, which can be used to enhance the understanding of FRC damage and fracture behaviour.

Synergistic effects of silica fume and slag on the microstructure and mechanical behaviors of ultra-high-strength and high-ductility cementitious composites

This work evaluated the synergistic effects of silica fume (SF) and ground granulated blast furnace slag (GGBS) binders on the microstructure and mechanical behavior of Ultra-High-Strength and High-Ductility Cementitious Composites (UHS-HDCC). The potential mechanisms of the synergistic effects of GGBS and SF on the fresh flow, mechanical properties, and microstructure of UHS-HDCC were investigated. The results indicated that the use of GGBS instead of SF could effectively improve the flowability of fresh mortar and UHS-HDCC mixtures. The hydration process of cement and the heat of hydration were delayed and reduced when the content of GGBS was below 25 %. Moreover, reducing the SF while increasing the GGBS reduced the compressive strength of the composites but had little effect on the flexural strength. The compressive strength of all specimens remained above 120 MPa. All specimens achieved strain-hardening behavior after the initial cracking of the matrix in uniaxial tension and four-point bending, and had a variety of cracking characteristics. Furthermore, the range of ultimate tensile strain capacity and mid-span deflection were 3.26 %–5.79 % and 16.73 mm–33.05 mm, respectively. The S10G30 specimen reached a maximum tensile strain energy of 414.6 kJ/m3. As the level of GGBS replacing SF increased, the number of cracks in the tensile region or the compressive bending surface of UHS-HDCC specimens increased, while the crack width and crack spacing decreased. The relatively smooth sidewalls of the fiber tunnels and fiber exit points meant that matrix fragments attached to the fiber surfaces were caused by matrix fragments generated throughout the matrix cracking process. Besides, the interfacial frictional stress and slip hardening coefficient acquired from the single fiber pullout test reduced with increasing levels of GGBS replacing SF.

Pullout test in steel fiber reinforced concrete

Use of steel fibers in cement-based composites has become popular due to possibility of using that material as total or partial replacement of conventional reinforcement, as in floor slabs or tunnel cover. This reinforcement aims to improve composites properties with regard, mainly, to cracks propagation. It’s known that concrete has high compressive strength and durability, but its toughness is low, being considered a fragile material. The performance of the fiber as stress bridge depends on several factors, among them bond strength between fiber and matrix. Interfacial Transition Zone (ITZ) is one in which first cracks that lead to material failure appear. Some researches with mineral additives, such as rice husk ash (RHA), are aimed at ITZ densification. RHA has a high content of amorphous silica, which gives it high potential for its pozzolanic activity. That RHA characteristic is able to potentiate new hydration products formation, especially C-S-H, giving a higher density to cement matrix and pores and voids reduction. Research’s objective was to evaluate the effect of cement substitution by RHA, aiming to densify cement matrix to point where the adhesion stress with steel fiber was higher than in conventional mixture. For this, control specimens were produced and 15% of the cement replaced by RHA. Through the single fiber pullout test it was possible to measure the adhesion stress between steel fiber and cement matrix. Results indicate an increase in the adhesion strength with a long curing time, which confirms that the RHA hydration occurs late in relation to cement.

Effect of electrophoretic deposition of micro-quartz on the microstructural and mechanical properties of carbon fibers and their bond performance toward cement

An electrophoretic deposition (EPD) process of micro-quartz (MQ) powder is applied to carbon fibers (CFs) with the aim to enhance their interfacial bond to cementitious matrices and to investigate its influence on the microstructural and mechanical properties of the CFs itself. The electrophoretic mobility of the MQ particles with negative charge in aqueous media was confirmed by potential sweep experiments and zeta-potential measurements. High amounts of MQ were successfully deposited onto the fiber surface, as proven by scanning electron microscopy. Single-fiber tension tests and thermogravimetric analysis showed that EPD treatment had little impact on the tensile properties and thermal stability of the modified fibers. However, storing the CFs in cement pore solution impaired temperature stability of untreated and modified fibers. X-ray diffraction and Raman spectroscopy reveal specific changes of CF's microstructure upon EPD treatment and immersion in pore solution. Single-fiber pullout tests showed that the pullout resistance of MQ-modified CFs was enhanced, relative to untreated CFs. This augmentation can be explained by an enhanced interlocking mechanisms between CF and matrix due to the deposited quartz particles on the CF surface.

Microscale evaluation of epoxy matrix composites containing thermoplastic healing agent

Among the strategies to produce healable thermosetting systems is their modification by the addition of thermoplastic particles. This work investigates the influence of poly(ethylene-co-methacrylic acid) (EMAA) on fiber-matrix interfacial properties of a glass fiber reinforced epoxy matrix composite. Epoxy-EMAA interactions were evaluated using differential scanning calorimetry (DSC) and infrared spectroscopy. The effects of EMAA on the epoxy network formation were evidenced by changes in glass transition temperature, cure kinetics and alteration of chemical groups during cure. Interfacial shear strength (IFSS) measurements obtained by single fiber pull-out tests indicate similar interfacial properties for pure and EMAA modified epoxy. Additionally, the potential for self-healing ability of an EMAA modified epoxy was demonstrated. However, IFSS after a healing cycle for the EMAA modified epoxy was lower as compared to the pure epoxy, because of the lower fiber-EMAA interfacial shear strength. So, thermoplastic healing agents has not only to fill cracks in the matrix material, but also have to be optimized regarding its interface properties to the reinforcing fibers.

Effect of heat treatment and end-hook geometry on pullout behaviour of heavily cold worked superelastic NiTi shape memory alloy fibres embedded in concrete

In this study, superelastic fibres were fabricated from heavily cold worked shape memory alloy (SMA) wire followed by heat treatment, with the goal of enhancing fibre pullout performance and simplifying the fibre production process. The effects of annealing at 350 °C, 450 °C, and 550 °C for 20, 40, and 60 min on the tensile properties of the cold worked SMA were studied. Monotonic and cyclic single fibre pullout tests were conducted using an embedment length of 30 mm. The fibres had straight, 3D, 4D, and 5D end-hook geometries and were embedded in normal strength (NS), high performance (HP), and ultra-high-performance (UHP) concrete. The results demonstrated that heat treatment at 350 °C for 20 and 40 min produced significantly higher peak load, pullout energy, average bond strength, and equivalent bond strength values as compared to the properties of fibres exposed to other temperatures and durations. Heat treatment at 350 °C for 40 min showed the highest re-centring and cumulative energy dissipation under cyclic pullout. Pullout performance significantly increased when either mechanical anchorage or concrete strength were increased. Among the SMA fibre geometries, 5D in NS concrete, 4D and 5D in HP concrete, and 3D and 4D fibres in UHP concrete generated sufficient resistance for martensitic transformation that resulted in a significantly higher re-centring ratio and cumulative pullout energy under cyclic loading than was observed for their steel counterparts.

Time-dependent behavior of pre-coated crimped, 4-Dimensional and 5-Dimensional steel fiber pull-out in normal and rubber concrete

Bond mechanism of various types of steel fiber embedded in normal and high strength concrete prepared without and with rubber particles are typically evaluated using single fiber pull-out test. Three distinct types of steel fiber, i.e., crimped (aspect ratio, l/d = 50 and 100), 4D (Double Hooked) and 5D (Triple Hooked) (l/d = 65) fibers embedded in different matrix strengths (M30, M30RC, M60 and M60RC), (RC-rubber concrete) were utilised. The fibers were pre-coated with Zinc Phosphate (ZnPh) in order to enhance the frictional resistance and bond strength between fiber and concrete which portrayed higher peak load than the un-treated fibers. Two different loading rates were adopted such as 1 mm/min (static loading) and 10 mm/min (dynamic loading) for single fiber pull-out test to examine the rate sensitivity on fiber pull-out for various conditions. Crimped fibers failed due to fiber rupture without attaining complete potential in most of the cases, at both loading rates. The pull-out load of 5D fiber was 1.37 times higher than that of 4D fiber at static loading rate. The dynamic increase factor of 4D and 5D fiber was found to be 1.31 and 1.23 respectively at dynamic loading for normal strength concrete, 1.21 and 1.15 respectively for high strength concrete on considering the effect of treatment of fiber. In the case of lesser embedment length, the fiber pulled off from the concrete matrix easily, especially at higher loading rates and in concrete prepared with addition of rubber particles. Performance of 5D steel fiber was found to be better in terms of Pmax and average shear stress.

Characterization of the effects of testing temperature on the interfacial shear strength of fiber/resin single-filament-composite

In the micromechanical test of fiber-reinforced composites, single fiber pull-out test is the most widely used test method. However, for high performance fibers/matrix, different test equipment and sensor accuracy can affect the single fiber pull-out test results very much. In this study, an innovative single fiber pull-out test method is proposed for testing the interfacial shear strength (IFSS) of high performance fibers/resins at different temperatures. Single fiber pull-out test was carried out on PBO fiber/epoxy resin (EP) composites at room temperature and elevated temperature. The IFSS was found to have an inverse relationship with the test temperature. The IFSS value of PBO/EP decreased from 25.25 MPa at room temperature to 6.25 MPa as the temperature approached the glass transition temperature. COMSOL simulations showed that fiber pull-out with angular tilt exhibited better interfacial strength, demonstrating the validity of the method. The results of this paper provide ideas to study the effect of temperature on the mechanics of fiber-reinforced resin matrix composites and expand the way to design stiffer, stronger and more robust composites.

Dynamic behavior of UHPC member under lateral low-velocity impact: Mesoscale analysis

Ultra-High Performance Concrete (UHPC), which mainly consists of the cementitious matrix and incorporated fibers, has superior impact-resistance compared with the normal strength concrete. Concerning the impact-resistant evaluation and performance-based design of UHPC structure under lateral low-velocity impact, a mesoscale modeling analysis approach considering the bond-slip behavior between random distributed fibers and cementitious matrix of UHPC is proposed. Firstly, the Continuous Surface Cap (CSC) model parameters for the matrix of UHPC were calibrated, and validated through a series of fundamental mechanical tests and low-velocity impact test. Secondly, by conducting a single steel fiber pull-out test, the fiber-matrix interaction was examined, and an appropriate interaction algorithm considering bond-slip effect was employed in the commercial program LS-DYNA. Then, the mesoscale model of UHPC was established through a self-coding program in MATLAB. The reliability of the mesoscale model and analysis approach were systematically verified at both material level (uniaxial compression, uniaxial tension, three- and four-point bending tests) and member level (total 15 low-velocity impact scenarios considering various member types, sectional shapes, sectional dimensions, and compressive strength). Finally, the influence of fiber volume fraction on the dynamic behavior of UHPC member was examined. It derives that the incorporated fibers can help reduce the lateral deflections and avoid the brittle punching-shear failure mode of UHPC members, and the optimal fiber volume fraction of 1.5% for the impact-resistant design is recommended. The present work provides a new way to accurately and conveniently evaluate the low-velocity impact-resistance and predict the dynamic behavior of the arbitrary configured UHPC structure.

Mechanical properties and its reliability prediction of engineered /strain-hardening cementitious composites (ECC/SHCC) with different moisture contents at negative temperatures

The mechanical properties of cement-based materials with different moisture contents are very sensitive to temperature. It is well known that engineered/strain-hardening cementitious composites (ECC/SHCC) are a high ductility cementitious composite material. The current research on SHCC is limited to room temperature and high temperature, and there is still a gap in the research on negative temperature. This study aims to explore the mechanisms of compressive strength and tensile properties of SHCC serving in cold environments. The effects of key parameters such as temperature (20 °C, −20 °C, −40 °C, and −60 °C) and moisture content (0%, 50%, 80%, and 100%) on the properties of SHCC were investigated comprehensively. With decreasing temperature and increasing moisture content, the compressive and tensile strengths of SHCC increased, while the tensile strain capacity decreased significantly. However, the tensile strain capacity of SHCC is still greater than 2% even at −60 °C. Micromechanical model parameters were obtained by fracture toughness and single fiber pullout tests, and the Pseudo Strain Hardening Behavior (PSH) criterion was calculated to explain the strain properties deterioration of SHCC at negative temperatures. Reliability prediction of the tensile strain capacity of SHCC at negative temperatures was made based on the Weibull distribution. The predicted results agree well with the experimental results. The predicted method can guide the design and engineering applications of SHCC in severe cold environments.

Evaluation of the bonding properties between low-value plastic fibers treated with microbially-induced calcium carbonate precipitation and cement mortar

Plastic fiber reinforced cementitious materials offer the potential to increase the reusability of plastic waste and create lower-CO2 cementitious composites. However, the bonding properties of many plastic types with ordinary Portland cement (OPC) are largely unknown. This work employs single fiber pullout (SFPO) tests to quantify the interfacial bonding properties of polyvinyl chloride, low-density polyethylene, polypropylene, polystyrene, and acrylonitrile butadiene styrene embedded in OPC mortar. The interfacial bonding properties were compared for fibers either treated with microbially-induced calcium carbonate precipitation (MICP) or left untreated. SFPO tests revealed that plastic type had a large influence over bonding properties. Specifically, the fiber surface energy, as estimated from water contact angle measurements, was found to be the driving factor of bond strength. ABS had the highest surface energy and demonstrated the strongest bonding out of all plastic types studied. However, MICP treatment of fibers did not increase the interfacial bond strength for any of the plastics studied. The thick and inconsistent coverage of biomineral over the fiber surface from MICP is likely attributed to preventing an increase in bond strength. These results contribute to the design and application of plastic-reinforced mortars by comparing bonding properties for a range of typically low-value, unrecycled plastic types.