Mechanical Properties Of Cement Composites Research Articles

Unraveling the reinforcing mechanisms for cementitious composites with 3D printed multidirectional auxetic lattices using X-ray computed tomography

This study investigates the mechanical properties of cementitious composites with 3D-printed auxetic lattices, featuring negative Poisson’s ratios (auxetic behavior) in multiple directions. These lattices were fabricated using vat photopolymerization 3D printing, and three base materials with varying stiffness and deformation capacities were analyzed to determine their impact on the composites’ mechanical behavior. To unravel the reinforcing mechanisms of multidirectional auxetic lattices, which exhibit auxetic behavior in both planar and out-of-plane directions, X-ray computed tomography (X-ray CT) was utilized to analyze composite damage evolutions under different strain levels. The micro-CT characterization reveals that auxetic lattices more effectively constrain crack growth and dissipate energy by distributing stress evenly within the cement matrix. In contrast, due to lack of lateral confinement, the non-auxetic lattice reinforced composites primarily dissipate energy through extensive crack propagation and interfacial damage, leading to lower peak strength. When strain exceeding 5%, although the confinement from the auxetic behavior diminished with crack propagation, the lattice can still maintain the composite’s structural integrity, resulting in 1.7 times higher densification energy than conventional cement-based materials. These findings provide valuable insights for designing auxetic lattice-reinforced cementitious composites with enhanced load-bearing capacity and improved dissipation capabilities.

Advanced cement composites: Investigating the role of graphene quantum dots in improving thermal and mechanical performance

The investigation of graphene quantum dots (GQDs) at very small nano- and atomic sizes is a novel approach in the fields of structural cement, concrete, and ceramic materials, which have not been thoroughly explored. This study investigates the comparative effects of two variations of GQDs, Qdl and Qdp, against a control mixture to assess the potential of graphene derivatives in enhancing thermal and mechanical properties of cement composites. The research presents their influences across a wide range of attributes, including flowability, bulk density, permeable voids, water absorption, compressive strength, flexural strength, surface temperature, thermal conductivity, thermal diffusivity, specific heat capacity, Brunauer-Emmett-Teller (BET) isotherm, thermogravimetric analysis (TGA), and microstructural characteristics. The empirical data underscore the superior freshness, physical, mechanical, and thermal attributes of GQDs-infused cement composites. Notably, the composites with 0.3 % Qdl show 20.8 % and 50 % increases in compressive and flexural strengths, respectively. On the other hand, the composites with 1.2 % Qdp show significant improvements in both compressive and flexural strengths, being 40 % and 108 % stronger than the control, respectively. Additionally, the thermal properties of the composites exhibit a proportional enhancement with increasing GQDs content. Microstructural analyses reveal a nano-bridging mechanism well-uniformly facilitated by the secondary nucleation and crystallization of calcium silicate hydrate (CSH) gel. This investigation offers innovative insights into the incorporation of GQDs in cement composites, highlighting their potential to create highly conductive structural cement and ceramic.

Effect of MWCNTs-OH on the mechanical properties of cement composites: From macro to micro perspective

This study is focused on elucidating the role and mechanism of hydroxyl-functionalized multi-walled carbon nanotubes (MWCNTs-OH) as a reinforcement material in cement-based composites. The dispersion of MWCNTs-OH within the cement composites was first assessed using Raman spectroscopy. Subsequently, SEM, FT-IR, TGA, XRD, and nano-indentation techniques were employed to investigate the structural transformation and phase changes occurring in the cement matrix upon incorporating MWCNTs-OH. The results reveal that MWCNTs-OH can significantly improve the macro-mechanical properties of cement composites by their capacity for pulling out, pore-filling, inducing multi-cracking, and promoting hydration. From a micro-perspective, observations of the micro-morphology demonstrate that MWCNTs-OH reinforces cement composites through crack-bridging and pull-out effects. Regarding the hydrated calcium silicate (C-S-H), the addition of MWCNTs-OH has a negligible impact on the ratio of low-density C-S-H (LD-CSH) to high-density C-S-H (HD-CSH). Moreover, the results obtained from FT-IR and XRD tests provide evidence that the bonding between MWCNTs-OH and the cement matrix is predominantly governed by physical interactions.

Improving electrical and mechanical properties of cement composites by combined addition of carbon black and carbon nanotubes and steel fibers

A cost-effective cement composite material has been developed for grounding systems, utilizing carbon black, carbon nanotubes, and steel fibers as conductive dopants. The electrical conductivity, mechanical properties, and fluidity of cement composites are investigated, and the synergetic mechanism of multiple conductive dopants in cement composites is revealed based on microscopic means. The results show that the combination of carbon black, carbon nanotubes, and steel fibers facilitates the establishment of efficient conductive networks in cement composites. The addition of 5 % carbon black, 0.3 % carbon nanotubes (by weight of cement), and 0.6 % steel fibers (by volume of composite) reduced the resistivity of the cement composite from 5568 Ω·cm to 310 Ω·cm after 28 days of curing. Then, it decreased to 267 Ω·cm after natural drying in laboratory environment until the 90th day. In addition, the resistivity of cement composites varies less than 5 % in environments ranging from −20°C to 50°C. Furthermore, the compressive and flexural strengths were 30.06 MPa and 6.17 MPa, and the flow diameter was 167 mm, which provided good mechanical strength and workability for conventional engineering applications. This paves an effective way for the further application of cement composites in grounding systems.

Durability and Mechanical Properties of Nano-SiO2 and Polyvinyl Alcohol Fiber-Reinforced Cementitious Composites Subjected to Saline Freeze-Thaw Cycles.

To investigate the effects of nano-SiO2 (NS) and polyvinyl alcohol (PVA) fibers on the durability and mechanical properties of cementitious composites subjected to saline freeze-thaw cycling, a series of PVA fiber-reinforced cementitious composite (PFRCC) specimens were prepared using various fiber contents, and a series of NS and PVA fiber-reinforced cementitious composite (NPFRCC) specimens were prepared using various combinations of NS and fiber contents. Durability and fracture toughness tests were subsequently conducted on the specimens after different numbers of saline freeze-thaw cycles. The results indicate that the degradation of material properties can be divided into slow and accelerated damage stages before/after 50 freeze-thaw cycles. The durability and fracture toughness of the specimen series tended to increase, then decrease with increasing NS and PVA contents, suggesting optimum levels. When the PVA fiber content was 0.5%, PFRCC specimens had the best durability after saline freeze-thaw cycles; when the NS and PVA fiber contents were 1.0% and 0.5%, respectively, NPFRCC specimens had the best durability and fracture properties, and the initiation toughness, destabilization toughness, and fracture energy after 100 saline freeze-thaw cycles were 120.69%, 160.02%, and 451.31%, respectively. The results of this study may guide future exploration of the durability and mechanical properties of concrete subjected to freeze-thaw action.

Predicting the compressive strength of carbon-enhanced cementitious composites using two-dimensional convolutional neural networks

This study addresses the limitations of traditional statistical methods and artificial neural networks (ANNs) in extracting relevant features from carbon-based cementitious composites to assess their dynamic behaviors under various environmental conditions. However, previous deep-learning methods were limited in making efficient predictions utilizing multiple factors. These shortcomings are not appropriate for predicting the properties of cement composed of various elements. In this study, these elements were converted into image form to handle efficiently the multiple factors that consist of cement, and the prediction was performed using a convolutional neural network (CNN)-based model. The concentration range of multiwalled carbon nanotubes (MWCNTs) used was 0.25 wt % to 1.0 wt %. Additionally, the specimens utilized were 50×50×50mm3 in size, and a total of 532 pieces of data were employed. Based on mean absolute error (MAE), performance was improved by approximately 25 % with ANN (MAE = 3.89) and 7.2 % with random forest (MAE = 3.14) compared with the proposed model (MAE = 2.92). The findings of this study are a novel and practical approach for predicting the mechanical properties of cementitious composites, enabling reverse application to optimize mixing ratios for CNT cement composites, and streamlining fabrication.

Effect of wet milling activation on mechanical properties and hydration process of cement composites with blast furnace slag

In this study, blast furnace slag (BFS) was activated using water- and ethanol-assisted milling (AM). BFS-cement composites (BFS-CC) were prepared using milled BFS and cement. The effects of the activation process on the mechanical properties and hydration of BFS-CC were investigated. Results showed that water- and ethanol-AM significantly reduced the median particle size (D50) and improved the particle size distribution of BFS compared to dry milling. Water-AM increased the compressive strength of BFS-CC at 3 days by 19.9 % and decreased the compressive strength at 28 days by 6.7 %. While ethanol-AM increased the compressive strengths at 3 and 28 days by 17.2 and 22.4 %, respectively. Water-AM improved the early strength of BFS-CC, whereas ethanol-AM contributed significantly to the late strength development of BFS-CC. This study provides an effective and convenient method for regulating the mechanical properties of cement composites containing high-volume BFS.

Predictive Modeling and Experimental Validation for Assessing the Mechanical Properties of Cementitious Composites Made with Silica Fume and Ground Granulated Blast Furnace Slag

Using sustainable cement-based alternatives, such as secondary cementitious raw materials (SCMs), could be a viable option to decrease CO2 emissions resulting from cement production. Previously conducted studies to determine the optimal mix designs of concrete primarily focused on either experimental approaches or empirical modeling techniques. However, in these experimental approaches, few tests could be performed for optimization due to time restrictions and lack of resources, and empirical modeling methods cannot be relied on without external validation. The machine learning-based approaches are further characterized by certain shortcomings, including a smaller number of data points, a less robust connection among the controlling factors, and a lack of comparative analyses among machine learning models. Furthermore, the literature on predicting the performance of concrete utilizing binary SCMs (silica fume (SF) and ground granulated blast furnace slag (GGBS)) is not available. Therefore, to address these drawbacks, this research aimed to integrate ML-based models with experimental validations for accurate predictions of the compressive strength (CS) and tensile strength (TS) of concrete that includes SF and GGBS as SCMs. Three soft computing techniques, namely the ANN, ANFIS, and GEP methods, were used for prediction purposes. Eight major input parameters, including the W/B ratio, cement, GGBS, SF, coarse aggregates, fine aggregates, superplasticizer, and the age of the specimens, were considered for modeling. The validity of the established models was assessed by using external experimental validation criteria, statistical metrics, and performance measures. In addition, sensitivity and parametric analyses were performed. Based on statistical measures, the ANFIS models outperformed other models with higher correlation and lower statistical error values. However, the GEP models exhibited superior performance compared to ANFIS and ANN with respect to the closeness of the RMSE, MAE, RSE, and R2 values between the training, validation, and testing sets for both the CS and TS models. Experimental validation showed strong evidence for the applicability of the proposed models with an R2 of 0.88 and error percentages of less than 10%. Sensitivity and parametric investigations demonstrated that the input variables exhibited the patterns described in the experimental dataset and the available literature. Hence, the proposed models are accurate, have better prediction performance, and can be used for design purposes.

THE INFLUENCE OF TOTAL WATER-TO-CEMENT RATIO ON THE MECHANICAL PROPERTIES OF CEMENTITIOUS COMPOSITES INTERNALLY CURED WITH POLYACRYLIC SUPERABSORBENT POLYMERS (SAP)

Superabsorbent polymers (SAP) allow for the introduction of changes to the pore network characteristics in cementitious composites and the course of binder hydration. Therefore, SAP addition contributes to significant changes in multiple properties of concrete. The effect of internal curing differs depending on its design process – the initial content of curing water in the concrete mix, polymer characteristics and water absorption properties, the state in which it’s added (nonsaturated/hydrogel), and the design method regarding curing water content in the entire water content. The authors investigated those variables’ influence on selected concrete properties – compressive strength, water absorption, and shrinkage. All independent variables significantly influenced the studied properties of concrete. The increase in the total water-to-cement ratio led to a significant decrease in the mechanical properties of cementitious composites. Modification with the use of SAP added in the form of hydrogel had the most positive influence on the properties of concrete.

Analysis of the influence of mechanical properties of cementitious composites using submerged arc welding (SAW) slag recycled aggregate

Concern about the environment and the scarcity of natural resources has led to the search for more sustainable alternatives that minimize the environmental impact of all segments of society. Solid waste recycling has been presented as a good alternative to reduce the impacts generated by the disorderly use of raw materials and the reduction of disposal areas, caused by the large volume of waste disposal generated throughout the year throughout the world. In this context, waste from industries in Brazil is included, especially submerged arc welding (SAW) slag. Waste from these activities is generally solid, with dense materials and variable characteristics in terms of their chemical composition, as they contain different types of elements with a specific function as a load element. These characteristics often present an obstacle to being reused in new materials (flows). Among the various waste generated by various industries, we can mention submerged arc welding (SAW) slag, as being one of the greatest potentials for use, due to often having knowledge of its basic characteristics and properties and its lower degree of contamination by other materials, when compared to other waste, such as construction waste. The objective of this research is to evaluate the mechanical performance characteristics of cementitious matrices made with submerged arc welding (SAW) slag residue and their possible use on a large scale. Cementitious matrices for mortars were manufactured by replacing 0%, 25%, 50% and 75% of the natural fine aggregate with submerged arc welding (SAW) slag residue and a water/cement ratio of 0.48. Through the compressive and tensile strength test, it was observed after 28 days that the cement matrices with replacements obtained increases in the mechanical properties of compressive and tensile strength, compared to the reference cement matrix.

Towards development of cement-based composites reinforced with architected 3D-printed polymers

In the present work, mortar beams reinforced with polymeric reinforcing elements are manufactured using Polylactic acid (PLA), inspired by crack propagation deflecting architectures found in nature such as Sinusoidal and Bouligand architectures. Mechanical flexural properties of mortar beams are studied and compared with that of reinforcing elements with an architecture parallel to the direction of tensile stress as well as non-reinforced mortar beams. Furthermore, the reinforcement configuration and ratio are designed using principles from mechanics of materials. A Digital Image Correlation (DIC) technique is used to obtain the load-deflection curves during flexural evaluation. Results show that changing the microarchitecture of the reinforcement can enhance the flexural performance of the beam. Additionally, interface properties between the mortar and the reinforcing element are studied using pull-out tests. Interface properties were enhanced by introducing architectural patterns on the surface of the reinforcement. Finally, using material properties of the mortar, reinforcement and the interface obtained from experiments, a numerical model is developed and calibrated. The outcome of this study helps explore the opportunities of using novel nature-inspired reinforcement to enhance the mechanical properties of cementitious composites.

Shrinkage cracking and mechanical properties of cementitious composites produced with multiwall carbon nano tubes and different types of polypropylene fibres

This study was conducted to experimentally demonstrate the control the nano-, micro- and macro-scale cracking in cement-based composites by using nano-, micro- and macro-scale fibres. While micro, macro and hybrid system polypropylene (PP) fibres were used in concrete designs, micro-scale PP and multi-walled carbon nano tubes (MWCNT) were utilized in mortar mixtures. The progression of the cracks was monitored in accordance with a well-known standard and also with a modified method which enabled the investigation of plastic and restrained shrinkage. Fracture energy, flexural strength, compressive strength, modulus of elasticity and ultrasonic pulse velocity of the samples were also determined as the mechanical properties of the composites. Results showed significant improvements in the reduction of cracks, especially with hybrid fibres system.

Effects of a novel carbon nanomaterial on hydration, mechanics, and chloride binding of cement composites

Nanomaterials have made significant progress in the field of cementitious materials, but suffer from primary problems of high cost and poor dispersity. Carbon dots (CDs) as a novel low-cost and high-dispersity nanomaterial preliminarily demonstrate their potential for cement. Nevertheless, it lacks systematic research on their effects on cement properties. For the first time, this work comprehensively investigates the effects of CDs on the hydration, mechanics, and chloride binding of cement composites. More importantly, the relevant mechanisms are revealed in depth. Specifically, cost-efficient ($0.013/g) and well-dispersed (dispersed in simulated concrete pore solution for 7 d) CDs are directly prepared by a facile microwave approach. The CDs dramatically retard the early hydration, improve later mechanical performance, and obviously enhance chloride binding. In detail, 0.2 wt% CDs reduce the second exothermic peak value by 75%, but improve the chloride binding capacity of paste by 51%. And 0.1 wt% CDs enhance the compressive/flexural strength of mortar by 17%/21%. Crucially, related influence mechanisms are uncovered. Namely, CDs create a protective barrier to retard hydration through the complexation of their abundant surface groups with Ca2+; While CDs exert the nucleation effect to boost the formation of C–S–H and Friedel's salt, thereby playing a positive impact on chloride binding; Meanwhile, CDs with suitable dosages carry out nucleation effect to counteract their air-entraining effect, thus improving later mechanical properties of cement composites. This study is expected to provide a novel low-cost and high-dispersity CDs nanomaterial to advance the development of high-performance cementitious materials.

Utilizing industrial byproducts for the manufacture of clay-cellulose nanocomposite cements with enhanced sustainability

This study investigates the influence of different nano clay contents (0, 1, 3, and 5 wt% of cement) on the microstructure and the mechanical properties of cement composites reinforced with varying Nano cellulose fiber contents (0, 0.5, 0.75, and 1 wt% of cement). Unlike previous research that employed sonication to improve dispersion in the cement matrix, this study explores the effects of unsonicated nano-cellulose addition and the combined incorporation of nano-cellulose and nano-clay. The results demonstrate that these additions significantly enhance the compressive strength, abrasion resistance, and water absorption ratios of the cement composites. Furthermore, the inclusion of nano-clay improves the microstructure of the cement matrix, strengthening the interfacial transition zone and reinforcing the bond between nano-cellulose and the cement matrix. The microstructural analysis using scanning electron microscopy (SEM) reveals the presence of a dense interconnected structure characterized by rod-like crystals. This research contributes to the development of sustainable construction materials by examining the effects of nano-cellulose and nano-clay on the properties and microstructure of cement composites. The utilization of industrial byproducts, such as wood sawdust, for the extraction of nano-cellulose offers an eco-friendly approach to enhance the performance of cement-based materials. The maximum compressive strength obtained, after 28 days, was at mix with 0.75% NCL + 5%NC with a gain of 53.5% than that of the control mix. In mixes containing only nano-clay (NCL), the increase in NCL content led to a higher rate of water absorption in the cement matrix, which reaches 4%. Confirming the results obtained from compressive strength and water absorption, mix with 0.75% NCL and 5% NC had obtained the optimum values with an improvement of 20% than that of the control mix.

Analysis of the Influence of PET and Glass Packaging Waste Materials on the Physical and Mechanical Properties of Cementitious Composites

The limited availability of natural resources, such as sand, and the need to reduce CO2 emissions, which are produced in large quantities in the production of binding materials, indicate the need to look for alternative raw materials used in construction materials. At the same time, there is a strong need to utilise waste packaging materials, the global production of which is constantly increasing. This work aims to investigate the possibility of using recycled polyethylene terephthalate (PET), utilised as a partial substitute for fine aggregate, and waste glass, implemented as powder, serving as a partial substitute for cement in the manufacturing of the cementitious composites. An experimental study was carried out to evaluate the physical and mechanical properties of the resultant cementitious composites. The incorporated PET aggregate comprised 0%, 5%, and 10% by volume of silica sand and 0%, 10%, and 20% glass powder by weight of cement. The addition of waste raw materials augmented the flow of fresh mortars, predominantly subsequent to the introduction of PET recyclate. The deployment of artificial aggregate in mortars induces a decrease in the volumetric density. Concurrently, the mechanical properties of mortars enriched with waste materials exhibited a reduction, in terms of both compressive and flexural strength, with the detriment escalating in conjunction with the content of waste raw materials. An analysis of statistical significance of effects, grounded in an analysis of variance, is delineated within this document, pinpointing the quantities of waste raw materials that can be assimilated in mortars without inducing a substantial deterioration of strength properties. Through studies on phase composition, it has been demonstrated that the utilised glass waste, possessing a grain size analogous to cement, exhibited poor pozzolanic properties. The test results indicate that it is possible to partially replace cement with glass powder, up to 10%, and fine aggregate with PET waste, up to 5%, without a significant reduction in the mechanical properties of the material.

Graphene nanoribbons as a novel nanofiller for enhancing the mechanical and electrical properties of cementitious composites

Several functional fillers have been used to modify the mechanical and electrical properties of cement-based materials. Graphene nanoribbons (GNRs) have attracted considerable attention as the next generation of carbon-based nanomaterials owing to their excellent properties. This paper aims to assess the influence of GNRs with varying incorporation amounts (0.05, 0.10, and 0.15 wt% of cement) on the mechanical properties, hydration behavior, and electrical properties of ordinary Portland cement paste via mechanical strength test, isothermal calorimetry, thermogravimetric analysis, X-ray diffraction, and alternating current electrochemical impedance spectroscopy. The enhanced performance of GNRs in cementitious composites was compared with that of carbon nanotubes (CNTs), which are one of the most popular and conventional nano-reinforcing agents for cement-based materials. The results of this study show that, compared to CNTs, GNRs significantly decrease the resistivity of cementitious composites owing to their excellent electrical properties. Furthermore, after the exfoliation of CNTs, GNRs possess a larger specific surface area and exhibit improved dispersibility. Thus, GNRs provide better nucleation and filling effects for cementitious composites to promote the hydration reaction of cement clinkers and modify the microstructure of the cement matrix, resulting in enhanced mechanical properties of the cementitious composites.

Effect of multi-walled carbon nanotube/Porous Carbon/SiO2 on reinforcing of cement mortar matrix: Modeling studies of effective parameters

The enhancement of the mechanical properties of cement composites by various nanomaterials is now a trendy subject. This study assessed the impact of three nanomaterials on the compressive and tensile strength of Portland cement mortar: biomass-derived porous carbon, MWCNT, and SiO2. These nanoparticles were developed using environmentally friendly, inexpensive technologies, and they underwent material characterization analyses using FESEM, N2 adsorption-desorption, contact angle, FTIR, XRD, and TEM. After 7 and 28 days, the compressive and tensile strength was assessed. According to the findings, among the samples, cement-SiO2 had the maximum compressive strength (19.32 MPa). The FESEM micrographs amply support the creation of the C-H-S gel and the presence of the bridge. The outcomes further showed that the nanoparticle's presence in the matrix does not significantly impact the tensile strength. SiO2-cement had the highest tensile strength, 1.45 MPa, matching the conclusions drawn from the compressive strength. Moreover, the compressive strength of cement was unaffected by the total pore volume of nanomaterials or the pore-filling mechanism of cement. Modeling (Linear regression-least square method) made it possible to predict the compressive strength for a period of 92 days and examine the influence of effective ingredients on it. Ultimately, the results indicate that porous carbon and silica can be viable alternatives for MWCNT.

Preparation of In(OH)3@GO with high surface roughness and its effect on the hydration performance, microstructures and mechanical properties of cement composites

The smooth surface of graphene oxide (GO) leads to a limited interaction with hydrated cement paste, which severely compromises its benefits to improve the properties of cement composites. In this study, GO dispersion (GOD) and indium chloride were employed to prepare In(OH)3 loaded GO (In(OH)3@GO) with high surface roughness and specific surface area. In(OH)3@GO obtained using indium chloride and GOD at a mass ratio of 4:100 (IG-4) exhibited increases in surface roughness and specific surface area of 67.6 % and 49.9 %, respectively, compared to GO without In(OH)3 (IG-0). In(OH)3@GOs were introduced into cement composites to analyse the impacts of varied In(OH)3 loading on mechanical properties, hydration performance and microstructure. Compared to IG-0, GO loaded with various amounts of In(OH)3 exhibited beneficial effects on cement composites. In particular, cement composite with IG-4 exhibited compressive strength improved by 26.4 %, flexural strength improved by 38.1 % and total pore volume reduced by 32.4 %.

The effects of apricot kernel shell nanobiochar on mechanical properties of cement composites

Valorization of agricultural wastes is important both economically and environmentally. This study aimed to investigate the use of biochar as a filler to improve the mechanical properties of mortar and to help sequestrate CO2. The biochar was produced by pyrolysis of apricot kernel shell at 500 °C. Nanobiochar particles with dimensions less than 500 nm were obtained by high-energy ball milling process. Scanning electron microscope was used for determining the morphology of nanobiochar. The nanobiochar at different volume percentages [0.00-0.04-0.06-0.08-0.12-0.15%] was added to mortar. The mortar was casted into 40x40x160 mm molds. After water curing at 20°C for 28 days, compressive strength and flexural strength tests were performed. The mixture containing 0.04% nanobiochar by volume had an increase in flexural and compressive strengths by 5% and 15% respectively, while its fracture energies for flexure and compression increased by 98% and 38% respectively compared to the reference mortar. Furthermore, the mixture having 0.12% volume had an increase in flexural and compressive strengths by 32% and 11%, respectively, while the increase in fracture energies for flexure and compression was 52% and 25%, respectively, compared to the reference mortar. The mechanisms of nanobiochar effect on flow, strength, and fracture energy were enlightened. The nanobiochars bridge the cracks, divert the cracks, act as hydration nucleation sites, enhance the matrix by its porous structure, and developed internal curing that led to increase in strength and fracture energy. This study suggests that the biochar produced from the apricot kernel shell has the potential to be used as a carbon sequestering mixture to improve performance of mortar and thereby utilizing waste as a construction material, contributing to the economy and environment.

Multifunctional properties of carbon fiber integrated cement composite – A review and insights

This article examines the strength characteristics of carbon fiber-reinforced cement composite (CFRCC). The research explores the residual mechanical characteristics and microstructure of concrete reinforced with carbon fiber. The review also focused on the determination of the effect of CFRCC on the improvement of strength, microstructure, crystalline phase shift, and hydration products of the cement composites. The review indicates that the inclusion of carbon fibers can intensify the flexural and splitting strengths of CFRCC, but the compressive strength is magnified to a lesser extent. In addition to the initial elastic modulus and peak stress of carbon fiber-reinforced cement composite, a discernible strain-rate hardening effect was also observed. This indicates that carbon fiber-reinforced cement composite has a promising future as cement composite reinforcements. The review of the characteristics of the composites also suggests their applicability in tunnel building in the cement composite. It is determined that carbon fiber-reinforced cement composite has a stronger capacity to withstand impact loads, and further information about its features will be supplied. The scanning electron microscopy (SEM) result demonstrates that the single and most significant failure mode under stress is carbon fiber breaking and the pull-out of carbon fibers. Thus, the review reveals that carbon fibers have a limited but positive act on enhancing the mechanical properties of cement composites.