Polymer Mortar Research Articles

Evaluation of Polymer Modified Mortar and Bonding Agent for Structural Repair

olymer modified mortar is found to be suitable for structural repair and strengthening of damage structural elements. Conventional mortar is not preferred in repair of concrete since it has inferior mechanical property and durability performance. Polymer based mortar is an alternative to conventional mortar with enhanced mechanical properties. However, there are limited specifications and guidelines available for specifying PMM mixes for structural repair work. The research work aims to evaluate the mechanical performance of polymer based mortar with varying concentration of styrene butadiene rubber latex at laboratory scale. Another aspect in repair of corrosion damage structures is the bond between the substrate concrete and repair mortar. In order to study the effectiveness of bonding agents, the performance evaluation of bonding agents has been evaluated using slant shear test and pull-off test as per ASTM C 882 and EN 1542 respectively. Findings of study indicates that at 8-10 percent concentration of dry polymer solid by cement mass in polymer based mortar is the optimum dosage. Styrene-butadiene rubber based polymer mortar showed improvement in flow in comparison to normal mortar however, mixes with crushed sand shows decrease in flow which is due to presence of more fines. Slant shear and pull-off test method shows epoxy bonding agent give better bond strength as compared to SBR latex.

Pembuatan Mortar Polimer Nanokomposit Sebagai Bahan Perbaikan

Construction in the field can often be encountered with various problems, one of which is damage to concrete structures or non-concrete structures that can affect the weakening of a structure. Many developed countries have carried out polymer mortar development efforts. Until now, the development of polymer mortar is still ongoing to reduce the use of cement and anticipate global warming. One of them is by utilizing polymer as an adhesive substitute for cement so that a strong mortar is produced in a shorter time. This research combines 40%-55% epoxy resin and hardener, 40% fine aggregate, 5%-20% Fly Ash and 1%-5% nanosilica. The results obtained show that the initial bond setting time is 70 minutes and the final bond is 110 minutes. This result is faster than normal mortar. The more epoxy used, the longer the bonding time. For Compressive strength test maximum Theobtained were results62 MPh with a mixture of 38% epoxy and hardener, aggregate 40% fine, 20% fly ash and 2% nanosilica. For specific gravity, the result is 1,760 Kg/M3. Aggregates and fly ash with fine grains can produce higher mechanical strength as fillers coupled with nanosilica which can increase strength, the more nanosilica used , the strength of the nanocomposite material increases to appoint critical and then decreases.  Keywords: Polymer Concrete, Fly Ash and Nanocomposites

Effect of calcined kaolin clay on mechanical and durability properties of pet waste-based polymer mortar composites

This study attempted to prepare a novel polymer mortar (PM) composite comprising unsaturated polyester resin (UPR) derived from polyethylene terephthalate (PET), as a replacement for cement; calcined kaolin clay as a filler; and silica sand as an aggregate. The UPR resin was synthesized by depolymerizing PET waste using propylene glycol and modifying it with styrene (UPR1) and methyl methacrylate (UPR2) monomers. Most previous studies have focused on the effect of kaolin clay filler on the properties of Portland cement concrete, whereas the effect of kaolin clay filler and sand grading on the properties of UPR resin PM has not been examined. In this study, the effects of UPR1 (UP:styrene) resin, UPR2 (UP:MMA) resin, calcined kaolin clay, and silica sand (zones I, II, and III) on the mechanical and durability properties of a PM composite were investigated. The polymer mortar (PM) mixture design was optimized through the design of the experiment (DOE) using Taguchi and ANOVA analyses. The compressive, tensile, and flexure strengths of the UPR2 PM formulation increased by 19.48, 25, and 28.21 %, respectively, compared to UPR1 PM. In addition, UPR2 PM with 20 % kaolin clay and sand (II) exhibited a decrease in water absorption, mass loss, and loss in compressive strength by 28.20, 15.90, and 7.31 %, respectively, compared to PM containing 18 % kaolin filler and sand (I). Moreover, the experimental results indicated that sand grading significantly influenced the properties of the UPR PM composite. The UPR resin prepared from waste PET and modified using MMA can be successfully used as a binder in PM composites to prepare mortar for interior decoration, repairing, grouting, and lightweight precast products in construction applications.

Performance of Fly Ash-Based Inorganic Polymer Mortar with Petroleum Sludge Ash.

Petroleum sludge is a waste product resulting from petroleum industries and it is a major source of environmental pollution. Therefore, developing strategies aimed at reducing its environmental impact and enhance cleaner production are crucial for environmental mortar. Response surface methodology (RSM) was used in designing the experimental work. The variables considered were the amount of petroleum sludge ash (PSA) in weight percent and the ratio of sodium silicate to sodium hydroxide, while the concentration of sodium hydroxide was kept constant in the production of geopolymer mortar cured at a temperature of 60 °C for 20 h. The effects of PSA on density, compressive strength, flexural strength, water absorption, drying shrinkage, morphology, and pore size distribution were investigated. The addition of PSA in the mortar enhanced the mechanical properties significantly at an early age and 28 days of curing. Thus, PSA could be used as a precursor material in the production of geopolymer mortar for green construction sustainability. This study aimed to investigate the influence of PSA in geopolymer mortar.

Seismic Behavior of Stone Masonry Joints with ECC as a Filling Material.

This paper investigates the seismic behavior of novel stone masonry joints using ductile engineered cementitious composite (ECC) as a substitute for ordinary mortar. Ten stone masonry joints with different types of mortar/ECC were tested under axial and cyclic loads. The filling materials of mortar joints tested included ordinary mortar, polymer mortar, ECC, and composite mortar with two combination proportions of ECC and ordinary mortar. The test results indicated that ECC specimens exhibited a more stable hysteretic response as well as an improvement in strength, deformation, energy dissipation, and strength degradation. The ECC mortar joints maintained integrity during the entire loading process due to the “self-confinement” effect of ECC. A partial substitution of mortar with ECC could provide effective reinforcement and confinement to prevent mortar failure and peeling, thereby allowing such specimens to approach the seismic performance of ECC specimens. Based on the trend of shear strength variations, a corresponding failure process is defined for ECC/mortar joints under cyclic and axial compressive loads, including four distinct stages: linear elastic, crack-developing stage, interface debonding, and friction sliding. New equations are proposed for predicting the shear strength and residual shear strength of the ECC/mortar joints on the basis of the test results, which are validated in the composite mortar specimens.

Evaluation of effectiveness of palm oil fuel ash as green filler and methyl methacrylate as additive in recycled PET resin polymer composite

A study was conducted to reduce the solid waste problem by developing the mortar composite from recycled polyethylene terephthalate (PET) and palm oil fuel ash (POFA). Styrene in recycled PET resin is partially replaced by 0–40 wt% methyl methacrylate (MMA). The uncured and cured properties of the nine different resin compositions were evaluated. Furthermore, the resin was optimized through a linear regression analysis depending upon test results, and the optimized resin was used as a binder in a polymer mortar (PM). The PM mixtures were prepared with varying content of optimized resin (10%, 12%, 14%), POFA filler(16%, 18%, 20%), and silica sand (Zones I, II, III). The Taguchi and analysis of variance (ANOVA) were used to optimize the PM mixes based on mechanical properties. Results showthat the modification of PET resin by MMA decreases viscosity and temperature and increases gel time, leading to improved mixing and mechanical properties of UP:styrene composition. Increasing the resin content from 10% to 14% and POFA filler content from 16% to 20%, the compressive, tensile, and bond strength of PM mixes increases by 19.15%, 75%, 180%, respectively. Based on SEM, it was found that increasing the resin content, POFA content, and finer sand size reduces porosity, improves adhesion between particles, and forms a more; compact and dense mortar. Recycled PET modified MMA PM could be used as precision tool; machine bases, repairing industrial floors, tanks in chemical environments.

Effect of crumb rubber powder on mechanical properties and pore structure of polyurethane-based polymer mortar for repair

In this study, the effect of crumb rubber powder (CRP) on the mechanical properties and internal pore structure of polyurethane-based polymer mortar (PUM) were investigated. According to the principle of volume fractions replacement of sand by 0 to 15% (5% interval), the CRP with a particle size of 0.25 mm was incorporated in the various mixture of polyurethane-based polymer mortar. For each PUM mixture were tested for compressive and flexural strengths, bond tensile strength. Mercury intrusion porosimetry (MIP) was used to analyze the distribution of pore size inside the material. The results show that the addition of 5% CRP was beneficial to improve the mechanical performances and the internal pore diameter distribution of PUM. No reduction in compressive and flexural strengths and the bond tensile strength was effectively increased by 7.9% and 17.3%, respectively. The total pore volume and porosity were reduced. Overall, the PUM contenting 5% CRP was recommended for repair.

Strengthening of a Reinforced Concrete Bridge with a Composite of Prestressed Steel Wire Ropes Embedded in Polyurethane Cement

This paper describes an innovative technique, a composite of prestressed steel wire ropes (PSWRs) embedded in polyurethan-cement composite (PUC), used to strengthen a 34-year-old reinforced T-beam bridge. PUC was mixed with polyurethane raw material and cement to provide good mechanical properties. Compared to using polymer mortar for PSWR strengthening, using PUC not only increased the durability of the steel wire ropes but also reinforced the main beams in the PSWR-PUC-strengthened composite. To study the effect of polyurethane cement, one span of the bridge was reinforced by a composite of PSWRs embedded in polymer mortar (PM). Static and dynamic load tests were carried out to test the corresponding responses of the experimental bridge. A finite-element model was used to verify the bridge test results. This study showed that the structural capacity and performance of the bridge were enhanced with PSWR-PUC strengthening. Compared with PSWR-PM reinforced spans with more prestressed steel wire ropes, PSWR-PUC reinforced spans retained good structural capacity.

Full-scale testing of adhesively bonded timber-concrete composite beams

This paper presents new findings on adhesively bonded timber-concrete composites with prefabricated concrete parts. Hereby, timber and concrete are bonded solely with adhesive and no metallic connectors have been used. Because the achievement of a continuous bond proved to be a critical point in past studies, special attention is given to that issue. The application procedure of the adhesives is investigated in small-scale bond samples and the manufacturing process in full-scale composite beams with a span of 8 m and a comparatively new polymer mortar is used as adhesive as well as a common epoxy resin. Both adhesives proved to be suitable, although polymer mortars showed strong advantages in terms of applicability and bridging of gaps in comparison to the less viscous epoxy adhesive. The full-scale beams are tested under quasi-static and cyclic loading. The failure occurred more as a bending failure of the timber or compression failure of the concrete. A full bond could be achieved at all full-scale beams. Moreover, an analytical and a finite element model for the calculation of composite beams are presented and validated. It could be seen, that both deformation behavior and failure load are in good accordance with the test results.

Flexural strengthening of RC beams with BFRP or high strength steel bar–reinforced ECC matrix

This paper has investigated the flexural behavior of reinforced concrete (RC) beams strengthened with BFRP (basalt fiber reinforced polymer) or HSS (high strength steel) bar reinforced ECC matrix. A total of six strengthened RC beams and one control RC beam were tested under four-point bending up to their failure. The test variables included the cement matrix (ECC and polymer mortar), the reinforcements type (BFRP and HSS bars) as well as the reinforcement ratio (0.94% and 1.41%) of the strengthening layer. Two failure modes including the rupture of BFRP bars and the rupture of ECC matrix followed by the slippage of the steel bars were obtained in the strengthened beams. The rupture of BFRP bars dominated the failure of beams strengthened with BFRP bar reinforced cement matrix owing to the limited tensile strength of BFRP bars, and the percentage of enhancement in flexural capacity ranged from 18.6% to 47.8% compared with the control beam. The beams strengthened with HSS bar reinforced ECC matrix all failed due to the rupture of ECC matrix followed by the slippage of HSS bars, mainly owing to the high stiffness and strength of the HSS bars, leading to larger enhancements in flexural capacity at a range of 60.0–75.6%. In addition, a beam strengthened with BFRP bar reinforced polymer mortar was also tested with the purpose of conforming the advantage of ECC over polymer mortar as the matrix of the strengthening layer. The test results showed that the application of ECC matrix with BFRP bars resulted in larger enhancement in the yield and ultimate loads compared to the use of polymer mortar matrix. The difference between the two strengthening systems confirmed the excellent strain compatibility of BFRP bars and ECC matrix. Finally, a flexural theoretical analysis based on three possible failure cases was proposed, and its reliability was verified through comparing the test results and the theoretical predictions.

Analysis of different interface treatments between masonry of AAC blocks and reinforced concrete structure after uniaxial compression strength test

Autoclaved aerated concrete (AAC) masonry is widely used in civil construction but requires further investigation. Hence, this experimental study evaluated three types of interface treatment between the reinforced concrete structure and AAC masonry, in scale, after a uniaxial compression resistance test. The types of interface treatment considered are reinforcement with steel bars, with rough polymeric cementitious mortar, and without treatment. The maximum load capacity, displacements, and occurrence of cracks were analysed. The results showed that the maximum individual load capacity did not significantly differ among the examined groups. However, the analysis of the displacements and cracks showed that the group with steel reinforcement had the smallest displacements and largest cracks. This behaviour is owing to the greater solidarity of forces conferred by steel reinforcement.

Evaluation of mechanical properties of chopped glass/basalt fibers reinforced polymer mortars

Nowadays, Polymer Mortars (PMs) are among the most remarkable engineering products in the construction industry. These materials, which are manufactured using a completely different technique compared to Portland Cement Mortars (PCMs), have become increasingly popular as mortar types in both superstructure and infrastructure. PMs, which have high compressive and tensile strength compared to PCMs, have brittle behavior like PCMs. In this study, the influence of chopped fibers on the engineering properties and fracture modes of PMs is investigated. The research focuses on two different chopped fibers: chopped glass fibers and basalt fibers (CGFs and CBFs) and their influence on the physical and mechanical properties of PMs. In this regard, three different mixtures; M1 (0.5 % CGFs and 0% CBFs based on pure PC weight), M2 (0% CGFs and 0.5 % CBFs based on pure PC weight) and M3 (0.25 % CGFs and 0.25 % CBFs based on pure PC weight) were prepared and different mechanical tests were performed on the samples considering different curing times; 7, 14, 21 and 28 days. Besides, digital microscope (DM) and scanning electron microscope (SEM) examinations were performed to obtain detailed information about fiber pullout, fiber breakage, debonding or cracking in the matrix. As a result of the experimental studies and evaluations, it was found that chopped fibers have an influence on the mechanical properties and failure modes of PMs and CBFs are better additives compared to CGFs, with M2 giving more effective results in terms of mechanical properties.

Seismic Behavior of Brick Masonry Walls Strengthened with Different Types of Fiber Nets

To investigate the strengthening effect of fiber nets on the seismic behavior of brick masonry walls, carbon fiber nets (CFN), glass fiber nets (GFN) and basalt fiber nets (BFN) were applied to strengthen masonry walls with an external sticking method. Pseudo-static tests were carried out on eight walls with different strengthening conditions: one was not strengthened; six were strengthened on one side or both sides with CFN, GFN and BFN, respectively; and one was strengthened with CFN on both sides and then riveted with steel plates. The results showed that fiber nets could exchange the failure mode of the walls from shear failure to bending failure. The bearing capacity, energy consumption and ductility of the strengthened walls were improved, and the improvement of double-sided reinforcement was more notable. Epoxy polymer mortar is more suitable for masonry structure strengthened with fiber nets than acrylic polymer mortar because it can ensure the full participation of fiber nets. In addition, a calculation formula for the design value of seismic shear capacity of masonry walls strengthened with fiber nets was deduced, which can effectively predict the shear capacity of walls strengthened with fiber nets.

Flexural behaviour of RC beams strengthened with prestressed steel wire ropes polymer mortar composite

ABSTRACT This paper presents an experimental study on the flexural behavior of reinforced concrete (RC) beams strengthened with prestressed steel wire ropes-polymer mortar composite (PSWR-PM). The effects of reinforcement ratio of steel wire ropes, strengthening procedures, and unbonded length of the steel wire rope-to-polymer mortar interface were studied with large-scale bending tests on RC beams strengthened by PSWR-PM. The test results showed that the proposed strengthening technique could substantially increase the load carrying capacity of the RC beams. Both strengthening procedures were effective in enhancing the flexural behaviour of the RC beams, and strengthening procedure II could even restrain the debonding failure. The unbonded length of the steel wire rope-to-polymer mortar interface had a minor impact on the ultimate capacity when the anchoring length of the steel wire rope in the polymer mortar was sufficient. Moreover, a theoretical model was proposed to predict the flexural strength of RC beams strengthened with the PSWR-PM technique and the predictions showed good agreement with the experimental results.

Enhancement the Properties of Construction Urea Composition with Polymer Additive

This scientific article provides physicochemical studies where the addition of a gel polymer has a positive effect on the process of structure formation. The presence of chemical bonds between the components, a change in the morphology of the structure, a decrease in microporosity, an increase in the density and thermal stability of the urea composition are shown. Polymer composite materials are used as chemically resistant coatings, polymer mortars and polymer concretes. Along with such valuable properties as incombustibility, colorlessness, good miscibility with water, etc., urea resins and compositions based on them have a number of disadvantages. The object of the study is a carbamide composition with a quartz filler and an addition of a gel polymer, its structure formation and chemical resistance. The methodological basis of the study is the polystructural theory of composite building materials (CBM) and the modeling of the study of the chemical resistance of the urea composition in aggressive conditions. The issues of finding effective water-binding additives and studying their effect on structure formation, properties and technology of urea compositions remain relevant and require additional research. It is shown that with the optimal content of the gel-polymer additive in the composition of 0.13% of the filler weight, the compressive strength and specific impact strength increase by 17; 13% and shrinkage is reduced by 7%. It was found that due to the enhancement of the adhesive bond between the components and the improvement of the pore structure under the action of the gel-polymer additive, the chemical resistance of the urea composition with quartz filler increases. So, water, acid and alkali resistance are 0.75; 0.80 and 0.85 and which, respectively, are 6, 7 and 7 points higher than the reference composition.

Influence of aggregates, glass fibre reinforcement and recycled aggregates on polyester mortar

As the performances of unsaturated polyester mortar are related to its composition, this research is focused on the influence of the grain size distribution of the aggregates, glass fibres reinforcement and the use of recycled aggregates on its mechanical and physical properties and microstructure. It revealed that a higher fraction of coarse sand caused a decrease in compressive (2 to 3%), tensile splitting (10 till 14%) and flexural tensile (5 to 9%) strength since the interlocking effects decrease, while microstructure analysis reveals more cracks and air voids when the filler fraction is substituted. Moreover, the addition of a small amount of glass fibres, i.e. 0.20 vol%, resulted in a decrease of 0.9, 3.4 and 4.6%, respectively, in compressive, tensile splitting and flexural tensile strength, whereas the impact toughness doubled. The properties related to the microstructure indicate that this mixture is less compacted compared to a mixture without fibre reinforcement, although the ultrasonic pulse velocity increased with 2.5%. Furthermore, the study highlights the potential of recycled polymer mortar as aggregates since enhanced tensile (18.5 and 3.9% respectively, for tensile splitting and flexural tensile strength) and impact properties (an improvement of 41.8%) were observed, while the additional tests indicate that the mixture with recycled aggregates has a less dense structure compared to the reference mixture.

Experimental Study of Hygrothermal and Ultraviolet Aging on the Flexural Performance of Epoxy Polymer Mortar

This paper studies the effects of hygrothermal environment at different temperatures and ultraviolet (UV) radiation on the bending properties of epoxy polymer mortar (EPM). The microstructure changes of EPM during aging were studied by scanning electron microscopy, and the bending properties of EPM were predicted by the Arrhenius law. The results showed that the bending properties of EPM were greatly affected by the temperature in the hygrothermal aging, but not evidently affected by ultraviolet radiation in UV aging. The prediction of Arrhenius model shows that the EPM will steadily retain 92.8%, 89.1% and 79.4% of the original flexural strength after long-term hygrothermal aging at $$40^{\circ }$$ C, $$60^{\circ }$$ C and $$80^{\circ }$$ C, respectively.

The influence of stone joints width and roughness on the efficiency of biocementation sealing

Biocementation is being used to seal cracks in stone and concrete for retrofitting and consolidation works, as alternative to conventional solutions such as using polymeric mortar. As when such traditional techniques are used, joint thickness and roughness play an important role on sealing efficiency and this must be investigated when using biocement. The efficiency of biocementation to seal joints in stone samples considering simultaneously their width and roughness is discussed in this paper. Joints with 0.4, 0.7 and 1 mm width, having smooth and rough surfaces, were artificially created on basalt stone disks. The joints were treated by biocementation until become sealed, i.e., until fluid stop flowing through the joint. Adhesion achieved with the treatment was evaluated by tensile strength measurements in Brazilian splitting tests, in which the samples were split by the sealed joint. The joint surfaces separated after the splitting test were analysed by digital analysis of photographs and stereomicroscope images to check the presence and homogeneity of the precipitated biocement. The tensile strength was larger for the artificial joints with larger width and rough surfaces (maximum values found are 3.94 and 5.67 MPa for the smooth and rough surfaces, respectively). The values found were half the values measured for the intact rock (8 MPa), but still in the order of magnitude of Mega Pascal, therefore indicating strong adhesion between the stone and biocement. Biocementation treatment therefore appears to be adequate for sealing stone joints with different widths within the range investigated and variable roughness.

Recycling polypropylene and polyethylene wastes in production of polyester based polymer mortars

Although polymers were originally seen as an option to replace other materials due to their physicochemical properties and low cost, they have become an environmental problem due to poor final disposal practices. For these reasons, in the presented investigation, impact of waste polypropylene (wPP) from bottle caps and waste polyethylene (wPE) from bottles, on mechanical characteristics of polymer mortars were observed. Mortars were produced with unsaturated polyester resin at 20% ratio and silica sand at 80% ratio. Sand was replaced with the wastes at three different ratios as 1, 2 and 3 wt% and sizes as 0.71, 1.4 and 2.38 mm. Observations exhibited improvement about 27% for compressive strength when adding wPP particles; 30% on the compressive deformation (adding wPE) as well as 82% on the flexural deflection (adding wPP). Nevertheless, flexural strength and the elasticity modulus of polymer mortars decline by depending on the increment in content and sizes of the wastes used. That is highly connected to morphologies observed by SEM of the fractures polymer mortars.

Experimental study on bond performance of advanced material based on composite Portland cements developed for anchoring systems with post-installed reinforcement bars in concrete

Abstract This paper presents an assessment study on the bond performance of new advanced mortars based on composite Portland cements. These developed mortars are used as anchoring material for post-installed reinforcement steel bars in concrete. The anchoring mortars were developed by laboratory studies in the recent years and they met several performance criteria regarding the properties in plastic state as consistency, cohesiveness, stability and in hardened state as strength, rigidity, deformation volume and bond to support. Anchoring systems with post-installed reinforcement steel bars are obtained through installation of reinforcement bars into drill holes in hardened concrete and filled with flowable mortars which may be polymer or cement-based mortars. Generally, post-installed reinforcement bars are used to connect layers of new concrete to old concrete and also new members to old concrete members. So far, the most employed anchoring material is the polymer-based chemical resin which have some undisputed advantages, but the durability and long-term performance along the expected service life is questionable. Recently, inorganic-injection-type anchors have been developed in Japan. These anchors are composed of cement, aggregate and additive agents. In this study, the employed anchoring-mortars are exclusively based on hydraulic binder, namely composite Portland cements which are included in the European class of cement CEM II. These composite cements contain supplementary cementing materials (SCM) as fly-ash or limestone which are combined with Portland clinker at the manufacture. The bond strength of the reinforcement steel bars was assessed based on the prescriptions provided in the European assessment document EAD 330087 and EN 1881. These two technical norms are limited only to deformed reinforcement bars with characteristics in conformity with EN 10080 and designed based on EN 1992-1-1. Within this study, the shear load on the reinforcement bars post-installed into hardened concrete is not considered.