Polymer-modified Concrete Research Articles

Exploring cement content's impact on self-healing in super absorbent polymer-modified concrete

This study shows the impact of varying cement content while maintaining a constant water-to-cement (w/c) ratio on the performance of self-healing concrete. It also explores the effect of F-type fly ash on the self-healing mechanism of concrete. Self-healing concrete, incorporating super absorbent polymers, offers a viable remedy to diminish the detrimental effects of cracks, enhancing the durability and lifespan of concrete structures. While the w/c ratio is a crucial factor influencing concrete properties, the impact of varying cement content under a constant w/c ratio in self-healing concrete remains understudied. Therefore, this experiment involved preparing 18 different concrete mixtures using three distinct cement contents under three specific w/c ratios. Fly ash was mixed in half of the specimens. Super absorbent polymers are incorporated into all mixtures to facilitate autonomous healing by absorbing and retaining water, which is released upon crack formation. Specimens were pre-cacked using a stress-controlled UTM machine. To evaluate the self-healing mechanism, low water pressure permeability test, water absorption test, and image analysis were conducted at 7, 14, 28, and 56 days. The findings of this study show that a w/c ratio of 0.35 yielded the best performance which indicates a lower w/c shows a higher self-healing performance. Additionally, the specimen containing a higher cement content exhibited enhanced healing capacity compared to other specimens. However, the specimens with fly ash failed to show a satisfactory result on self-healing capacity because the addition of silicon-based fly ash (F type) created an adverse effect on the self-healing mechanism.

The effect of anti-slip aggregate and silica fume on polymer-modified concrete

AbstractProgress in building construction requires more durable concrete with higher strength. Polymer and water reducer liquids can improve concrete strength and durability. This research aims to improve the mechanical properties of polymer-modified concrete by using anti-slip sand and silica fume to achieve more durable concrete against sulfate attack and higher mechanical properties. The study shows an increase in compressive strength from 25.7 MPa for reference mix to 45.5 MPa using 15% silica fume and 30% Anti-slip sand; tensile strength increased from 2.72 to 4.4 MPa. Flexural strength also increased, and durability to sulfate attack also increased. The study includes the increment of durability against freezing-thawing cycles for different mixes.

Experimental study and theoretical prediction of axial compression behavior in PMC-reinforced CFST columns with void defects

Polymer-modified concrete (PMC) is a promising seismic reinforcement material to improve the ultimate load carrying capacity and ductility of structures. This study investigates the reinforcing effects of PMC on voided concrete-filled steel tube (CFST) columns through axial compression tests on 21 specimens. A meticulous analysis, incorporating void arch height, steel tube thickness, and PMC reinforcement, elucidates failure modes, load-deformation behavior, and strain characteristics. The experimental results demonstrate that PMC reinforcements significantly enhance the structural behavior and load-bearing capacity, improve ductility, and prevent material detachment from excellent bonding and collaborative working properties. A novel calculation model for ultimate load capacity and lateral pressure coefficient of voided CFST columns is developed and validated. Results reveal a distinct improvement in specimen performance post PMC reinforcement, with load-displacement curves resembling intact specimens, mitigating the impact of void defects. Furthermore, PMC-reinforced specimens exhibit effective recovery of load-bearing capacity and ductility, offering a cost-effective alternative to steel tube thickening. Changes in strain and Poisson's ratio curves underscore PMC's ability to restore biaxial compression stress, enhancing stability. Prediction models, rooted in the Double Shear Unified Strength Theory, accurately anticipate ultimate bearing capacity and lateral pressure coefficient, bolstering practical engineering design and repair endeavors. In summation, this study provides comprehensive insights into PMC-reinforced voided CFST columns, facilitating informed structural enhancements and repairs.

Thermal Performance of Polymer-Modified Concrete for Sustainable Building Envelopes

Thermal Performance of Polymer-Modified Concrete for Sustainable Building Envelopes

Improvement of the mechanical properties of polymer-modified concrete by using PC superplasticizer

AbstractIn this article, polymer-modified concrete was studied to present the effect of using additives on its mechanical properties. This will be achieved by employing a high-performance super plasticizing admixture that significantly enhances polymer-modified concrete mechanical capabilities. The study indicates that the polymer styrene-butadiene rubber (used increases concrete mechanical properties by 10% by weight. When the dosage exceeds 10% by weight of cement, the compressive, tensile, and flexural strengths of polymer-modified concrete are diminished. With the addition of a superplasticizer with a ratio of 1.2%, regular polymer-modified concrete compressive strength has increased from 34.3 to 42.9 MPa for a 10% polymer/cement ratio. Additionally, this superplasticizer enhanced the Material's flexural and tensile strength.

Biomineralisation to improve properties of polymer modified concrete for chloride environments

This research compares the performance of three types of polymer-modified concrete (TPE, LDPE/EVA, and PCL) if bacteria-based solutions are used for reinforced concrete (RC) structures designed for a compressive strength higher than 50 MPa in chloride environments. The aim is to understand the impact on mechanical and durability performance of concrete. These recyclable polymers' use is crucial to increasing the strength at 28 and 60 days. At 60 days, all polymer-modified concrete reached a compressive strength higher than 60 MPa. The use of bioproducts is crucial to lowering the open porosity values to 4%. However, the use of bioproducts tends to delay the increase of concrete's compressive strength with time, especially until the 14 days. The existence of tetrahedron and pyramid structures in polymer-modified bio concrete indicates that calcite is present, and the quantity of calcium carbonate in the polymer-modified bio concrete is significantly higher than in plain bio-concrete or even plain. The bioproduct plays a dominant role in the capillary control and prevents water migration more effectively in comparison to the use of different polymers in concrete. The bioproduct substantially minimise the migration of chlorides to 7 × 10−12 m2/s, a water-soluble ion in wet/humid concrete porous medium environments, but also at low relative humidity environments, as it happens when the concrete is exposed to capillary suction. The highest electrical resistivity values have been recorded in TPE bio-concrete.

Investigation on the Internal Relative Humidity of Superabsorbent Polymer–Modified Concrete Exposed to Various Ambient Humidities at Early Age

The drop in internal relative humidity (IRH) affects the early-age cracking risk of concrete. Superabsorbent polymers (SAPs), an internal curing material, are usually used to decrease the drop rate of IRH in concrete and the shrinkage-induced cracking risk of concrete. This study investigated the changes in IRH and distribution of IRH in SAP-modified concrete under sealed conditions and exposed to various ambient humidities. The test results showed that the use of SAPs and additional internal curing water can compensate for water consumption caused by self-desiccation and moisture diffusion (MD) and increase the IRH of concrete exposed to various ambient humidities. However, the degree to which SAPs mitigated the drop in IRH of concrete exposed to outside ambient decreased with increasing ambient humidity. The IRH of SAP-modified concrete increased, and the MD coefficient decreased nonlinearly with increasing ambient humidity. A model for predicting IRH of SAP-modified concrete exposed to various ambient humidities under the influence of self-desiccation and MD was proposed.

Mechanical performance improvement of super absorbent polymer-modified concrete

In this study, a method has been developed to reduce the negative effects of superabsorbent polymers on concrete mechanical properties. The method involves concrete mixing and curing, with the concrete mixture being designed using a decision tree algorithm. Instead of the standard water curing approach, air curing conditions were used during the curing process. In addition, heat treatment was applied to reduce any possible negative effects of the polymers on the concrete's mechanical properties and to enhance their performance. The details of all these stages are presented in this method. Various experimental studies were conducted to demonstrate the validity of this method, which proved to be effective in reducing the negative effects of superabsorbent polymers on concrete mechanical properties.•The method can be used to eliminate the negative effects of superabsorbent polymers.•The proposed method yielded promising results, demonstrating that the expected level of compressive strength, modulus of elasticity and toughness in concrete can be achieved in 5-10 days instead of 28 days•The widespread use of superabsorbent polymers in the concrete industry and reinforced concrete systems can be attributed to their many benefits.

The Evaluation of Physical and Mechanical Properties of Synthetic Polymer Modified Hot and Warm Mix Asphalt

The application of polymer in an asphalt concrete (AC) mixture has reached wide popularity lately to deal with the increasing demand for higher quality roads with heavier traffic loading. Ethylene-vinyl acetate (EVA), classified as a thermoplastic, is currently one of the most popular polymers employed. This research attempts to evaluate the effect of adding EVA by means of the dry method, namely by pouring the additive directly into the mixture, which produces both hot and warm Polymer-Modified Asphalt Concrete (PMAC) mix. FTIR result indicates the polymer as a thermoplastic material. Moreover, the volumetric and mechanical properties of the mixture were examined through the density and semi-circular bending (SCB) tests. The outcomes show that the inclusion of the polymer could slightly modify the density and VMA of the AC mix. Meanwhile, the tensile strength, fracture energy, crack resistance index (CRI), and flexibility index (FI) results describe substantial enhancement brought by the polymer, with a generally increasing trend up 200% of the control mix. Conclusively, the application of polymer could enhance the physical and mechanical properties of hot and warm AC mixes with the optimum dosages of 5 and 6%. Additionally, the properties of warm PMA are somewhat comparable to the regular hot AC mix.

Use of metakaolin with polymer modified concrete in repairing of structures

Polymer-modified concrete (PMC)/mortar (PMM) is used for repairing and restoration of structures. In PMC/PMM, a water based polymeric dispersion is used to replace cement binder in the concrete mix/Mortar. The biggest limitation of polymer is its shelf life and high cost. Application of MK can substantially reduce the cost and improve mechanical properties of PMC/PMM.In this paper MK was used as a partial replacement by weight of cement in PMC/PMM. The project was carried out in two stages; in the first stage, various mixes were cast for different proportion of MK as a replacement for binder (OPC and PPC). Compressive strength and water sorptivity were tested for all five compositions and it was found that mix with 10% MK (MK10) showed maximum improvement in strength and sorptivity. In the second stage, the proportion of polymer latex was varied in MK10 and it was found that the use of 10% MK and 0.5% polymer latex (by weight of cement) in the mix showed better strength and durability properties. The PMM mix was applied to deteriorated concrete structure to validate the laboratory data. The results thus obtained were found to be in line with the laboratory results.

Influence of accelerated curing on the compressive strength of polymer-modified concrete

Influence of accelerated curing on the compressive strength of polymer-modified concrete

Compressive Strength Prediction of Lightweight Concrete: Machine Learning Models

Concrete is the most commonly used construction material. The physical properties of concrete vary with the type of concrete, such as high and ultra-high-strength concrete, fibre-reinforced concrete, polymer-modified concrete, and lightweight concrete. The precise prediction of the properties of concrete is a problem due to the design code, which typically requires specific characteristics. The emergence of a new category of technology has motivated researchers to develop mechanical strength prediction models using Artificial Intelligence (AI). Empirical and statistical models have been extensively used. These models require a huge amount of laboratory data and still provide inaccurate results. Sometimes, these models cannot predict the properties of concrete due to complexity in the concrete mix design and curing conditions. To conquer such issues, AI models have been introduced as another approach for predicting the compressive strength and other properties of concrete. This article discusses machine learning algorithms, such as Gaussian Progress Regression (GPR), Support Vector Machine Regression (SVMR), Ensemble Learning (EL), and optimized GPR, SVMR, and EL, to predict the compressive strength of Lightweight Concrete (LWC). The simulation approaches of these trained models indicate that AI can provide accurate prediction models without undertaking extensive laboratory trials. Each model’s applicability and performance were rigorously reviewed and assessed. The findings revealed that the optimized GPR model (R = 0.9803) used in this study had the greatest accuracy. In addition, the optimized SVMR and GPR model showed good performance, with R-values 0.9777 and 0.9740, respectively. The proposed model is economic and efficient, and can be adopted by researchers and engineers to predict the compressive strength of LWC.

Properties of Cementitious Repair Materials for Concrete Pavement

This review aims to provide an insight into concrete pavement repair materials by gathering the relevant research outcomes and specifications. It provides a systematic literature review that focuses on pavement repair and types of cementitious repair material. In general, conventional cementitious repair materials can be divided into 4 categories: ultra-rapid, rapid, accelerated, and normal strength gain. The mechanical and durability properties of conventional cementitious repair materials, i.e., calcium sulphoaluminate-based, calcium aluminate-based, polymer-modified concrete, and ordinary Portland cement-based repair materials are highlighted. The paper also discusses the newly developed ultra-high performance concrete and alkali-activated materials as potential repair materials for concrete pavement due to the good mechanical and durability performance. As a final point, this review may help readers to understand and determine the appropriate type of repair material when distress occurs in concrete pavement.

Long-Term Durability of Bio-Polymer Modified Concrete in Tidal Flooding Prone Area: A Challenge of Sustainable Concrete Materials

The need for durable concrete in marine environments such as areas prone to tidal flooding is important due to its ability to deteriorate the structures. This led to the design of a durable and strong Polymer-Modified Concrete (PMC) using natural or bio-polymer modified concrete. However, the use of biopolymer-modified concrete is very limited. Therefore, this research developed a bio-polymer modified concrete using Gracilaria sp., Moringa oleifera, and honey (GMH) for column retrofitting. The research aimed to retrofit and improve the compressive strength and durability of broken columns submerged by tidal flooding by applying bio-polymer modified concrete with GMH. A field application of column retrofitting was conducted in areas prone to tidal flooding. The retrofitted columns performance was observed for 14 months and validated by non-destructive and destructive tests. The result showed that the compressive strength of the retrofitted column achieved 32.37 MPa, which is a 92.34% increase compared to the baseline. This research provides answers to the challenge of concrete materials sustainability by promoting bio-polymer modified concrete that significantly increased its performance and long-term durability using GMH.

Mechanical Performance of Single-Graded Copolymer-Modified Pervious Concrete in a Corrosive Environment.

Polymer-modified cement has found numerous applications due to its excellent tensile strength. When cement was modified with a single polymer, its tensile strength and performance marginally increased. However, when a small amount of the flexible polymer latex was added to cement, the mechanical performance of cement considerably improved. In this study, single-graded copolymer-modified pervious concrete was prepared by mixing styrene-butadiene rubber (SBR) with different acrylate polymers, and its mechanical performance and durability were systematically studied through mechanical tests and theoretical analyses. The main findings are as follows: (1) When a waterborne emulsion was added, the freeze resistance of cement concrete increased, and its mass loss rate decreased. Cement concrete with two latexes had higher sulphate corrosion resistance and substantially lower dry shrinkage strain than ordinary cement concrete. (2) Through scanning electron microscopy, the microstructural changes in the cement binder, ordinary polymer-modified concrete, and the copolymer-modified cement concrete used in this study were observed, and the findings were compared with those reported in the literature. (3) Single-graded copolymer-modified pervious concrete exhibited excellent shrinkage performance. This study showed that single-graded copolymer-modified pervious concrete satisfied the performance requirements for use as a paving material for special cases.

Experimental Study on the Mechanical Properties and Durability of High-Content Hybrid Fiber-Polymer Concrete.

Polymer-modified concrete and fiber concrete are two excellent paving materials that improve the performance of some concrete, but the performance of single application material is still limited. In this paper, polymer-modified concrete with strong deformation and fiber concrete with obvious crack resistance and reinforcement effect were compounded by using the idea of composite material design so as to obtain a high-performance pavement material. The basic mechanical properties of high-content hybrid fiber–polymer-modified concrete, such as workability, compression, flexural resistance, and environmental durability (such as sulfate resistance) were studied by using the test regulations of cement concrete in China. The main results were as follows. (1) The hybrid fiber–polymer concrete displayed reliable working performance, high stiffness, and a modulus of elasticity as high as 35.93 GPa. (2) The hybrid fiber–polymer concrete had a compressive strength of 52.82 MPa, which was 31.2% higher than that of the plain C40 concrete (40.25 MPa); the strength of bending of the hybrid concrete was 11.51 MPa, 191.4% higher than that of the plain concrete (3.95 MPa). (3) The corrosion resistance value of the hybrid fiber–polymer concrete was 81.31%, indicating its adjustability to sulfate attack environments. (4) According to cross-sectional scanning electron microscope (SEM) images, the hybrid fiber–polymer concrete was seemingly more integrated with a dense layer of cementing substance on its surface along with fewer microholes and microcracks as when compared to the ordinary concrete. The research showed that hybrid fiber–polymer concrete had superior strength and environmental erosion resistance and was a pavement material with superior mechanical properties.

Structural Design Calculation of Basalt Fiber Polymer-Modified RPC Beams Subjected to Four-Point Bending.

In this paper, a basalt fiber surface was treated with coupling agent KH-550 and hydrochloric acid, and the basalt fiber polymer-modified active powder concrete (RPC) material was prepared. There are significant differences in material composition and properties between basalt fiber polymer-modified RPC and ordinary concrete, and the structural design calculation (cracking moment and normal section bending bearing capacity) of an ordinary reinforced concrete beam is no longer applicable. Thus, mechanical parameters such as displacement and strain of reinforcement basalt fiber polymer-modified RPC beams subjected to four-point bending were tested. The excellent compressive and tensile strengths of basalt fiber polymer-modified RPC were fully utilized. The tensile strength of basalt fiber polymer-modified RPC in the tensile zone of the beam was considered in the calculation of normal section bending bearing capacity of reinforcement basalt fiber polymer-modified RPC beams. The results showed that the measured values of the cracking moment and ultimate failure bending moment of reinforcement basalt fiber polymer-modified RPC beams were in good agreement with the calculated values. The established formulas for cracking moment and normal section bending bearing capacity can provide references for the design of reinforcement basalt fiber polymer-modified RPC simply supported beam and promote the wide application of basalt fiber polymer-modified RPC materials in practical engineering.

Some Mechanical Properties of Polymer Modified Concrete by Adding Waste Iron Filings and Chips

The study aims to improve some mechanical properties like compressive strength, tensile strength, modulus of elasticity and flexural strength of polymer modified concrete (PMC). This improving for PMC done by using waste iron filling as replacement from fine aggregate. waste iron filings and chips used in this research as percentages from sand ranged from 0 % to 40 % , the compressive strength of ordinary polymer concrete increase from 32.2 MPa to 41.81 MPa by 40% replacement of sand with waste iron filings and chips, tensile strength increased also from 2.83 MPa to 4.23 MPa by 40% replacement also. Flexural strength increased from 3.7 MPa for reference mix to about 7.1 MPa for mixes with 40% replacement, modulus of elasticity increased from 21087 MPa to 25233 MPa by using maximum percentage of waste iron filings. There is a slight increment in mechanical properties of polymer modified concrete after 30% ratio of waste iron filings and chips. Also research includes mixes modified with larger dosage of super plasticizer and less water/cement ratio to improve mechanical properties of PMC.

The Effect of Polyacrylic Ester on Electrochemical Corrosion Behavior of Low-Alloy Steel in Polymer Modified Concrete Exposed to Marine Environment

The Effect of Polyacrylic Ester on Electrochemical Corrosion Behavior of Low-Alloy Steel in Polymer Modified Concrete Exposed to Marine Environment

Effect of Polymer SBR on Strength Reduction in Concrete Immersed in Drainage and Ground Water

Concrete structures suffer from the impact of many harmful attacking materials that affect theproperties of the main material in them, which is concrete. These structures are also, exposedto the negative impact of many hostile environments such as soils containing harmful salts andharmful acids. A number of precautions should be considered in order to protect the concreteused in such structures. Adding polymer to concrete components as a percentages weight ofcement is one of the methods for producing polymer-modified concrete, which has lowpermeability, better mechanical properties and is more resistant to the negative effects ofharmful environmental factors. The utilization of polymers could help in protecting structuresand enhancing concrete strength. In this study, concrete mixes were prepared with inclusion ofstyrene butadiene rubber (SBR) polymer at four percentages (0%, 5%, 7% and 10% by cementweight). Co-polymers of butidine with styrene (styrene-butadine rubber (SBR)), are a group oflarge-volume synthetic rubbers. High adhesion occurs between the polymer films that formand cement hydrates. This action gives improves the properties of concrete such as flexuraland compressive strength and gives also a higher durability. The investigation was extended toevaluate the compressive strength of the SBR concrete mixes immersed in three types ofwaters: tap, drainage and ground water, at three different ages. The results showed that SBRpolymer enhanced the compressive strength of concrete significantly. A comparison betweenreduction in strength of concretes immersed in these three types of waters was also presented.Moreover, the presence of SBR polymer led to reduced loss in strength of concrete specimensimmersed in drainage and ground water. A proposed model to determine the compressivestrength of concrete specimens immersed in drainage and ground waters was deduced. Thismodel could be a helpful tool for rapid and easy estimation of the strength of concretespecimens immersed in drainage and ground water at different contents of SBR polymer. Theresults showed the highest improve in compressive strength to be associated with 7% SBRmixes at the three tested ages. The increases in this strength at days 7, 28 and 56 with inclusionof 7% SBR polymer were 112.8%, 113.9% and 116%, respectively, compared to OPC mix.