Construction and Building Materials最新文献

{"title":"Influence of normal stress on the shear failure mechanisms of cement-rock composites","authors":"Panyu Liao ,&nbsp;Zhiwen An ,&nbsp;Fuming Wang ,&nbsp;Chengchao Guo ,&nbsp;Hongzhi Yao ,&nbsp;Dongfeng Bai","doi":"10.1016/j.conbuildmat.2025.140553","DOIUrl":"10.1016/j.conbuildmat.2025.140553","url":null,"abstract":"<div><div>Cement is a widely used grouting material in geotechnical engineering, and the bonding properties of cement-rock interfaces play a crucial role in the stability analysis of engineering structures. In this study, laboratory direct shear tests were performed on standard cube cement-rock composite specimens under varying normal stress. The shear failure mechanisms of the cement-rock composite were investigated using Acoustic Emission (AE) and Digital Image Correlation (DIC) techniques. The results show that increased normal stress enhances peak shear stress, residual shear stress, and the shear displacement corresponding to peak shear stress. The values of peak AE energy and ringing count at peak stress are significantly higher than those at other stages, indicating brittleness at the cement-rock interface. The evolution of the b-value and AE amplitude suggests that interface failure results from the repeated formation of large- and small-scale microcracks. The distribution of AE frequency and RA-AF values reveals the influence of normal stress on the types of cracks generated at the interface. Under normal stress conditions, cement-rock composites exhibit shear fractures, while tensile failure occurs in the absence of normal stress. The DIC analysis supports the efficacy of AE analysis in detailing the failure process. The scanning electron microscope results suggest that the interface cracks primarily originate from the fracture of hydration products.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"470 ","pages":"Article 140553"},"PeriodicalIF":7.4,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143512354","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Utilization of chromium-rich decarbonized coal gasification slag as mineral admixture in cemented mortar: Mechanical performance, hydration property and chromium immobilization","authors":"Xiaochuan Xu ,&nbsp;Yunqi Zhao ,&nbsp;Xiaowei Gu","doi":"10.1016/j.conbuildmat.2025.140614","DOIUrl":"10.1016/j.conbuildmat.2025.140614","url":null,"abstract":"<div><div>The utilization of aluminosilicate-rich by-products as supplementary cementitious materials has garnered great interest due to its environmental friendliness. In this study, a Cr-rich decarbonized coal gasification slag powder (DGSP) was conducted to reduce the large-scale application of cement, and hazardous heavy metal element was solidified simultaneously. Fluidity, setting time and compressive strength tests were carried out to evaluate macro-performances. Hydration calorimetry, X-ray diffraction, thermogravimetry and scanning electron microscope-energy dispersive spectrometer were used analyzed the property of hydration. Results showed that the hydration heat and early compressive strength were deteriorated with DGSP content due to its restricted reactivity. However, after 28 d and 90 d curing, the reticular C(-A)-S-H was mainly generated through pozzolanic reaction of DGSP, and interfacial transition zone was attenuated. The compressive strength of blended mortar was increased first and then decreased, and peaked at 30 wt% DGSP, where Cr leaching in DGSP was also restrained by 98.5 % through the physical solidification of C(-A)-S-H and chemical stabilization of CrO₄-U phase. The achievement of this study proved the feasibility of this decarbonized coal gasification slag powder in cementitious binders.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"470 ","pages":"Article 140614"},"PeriodicalIF":7.4,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143511577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Inhibiting pan-alkali in desulfurization gypsum-based materials with trace magnesium oxide: Synergistic interaction of polymerization degree, impair porosity and free water","authors":"Li Zhonglin ,&nbsp;Xu Ye ,&nbsp;Peng Biao ,&nbsp;Luo Wenbin ,&nbsp;Wang Lusen ,&nbsp;Zhu Jie ,&nbsp;He Zonghui ,&nbsp;Zhang Weiguang ,&nbsp;Fei Long ,&nbsp;Li Yibing","doi":"10.1016/j.conbuildmat.2025.140634","DOIUrl":"10.1016/j.conbuildmat.2025.140634","url":null,"abstract":"<div><div>The degree of alkalinity significantly affects the practical application of geopolymers by diminishing its compressive strength and durability, to improve the weathering resistance and durability of desulfurization gypsum (DG) based cementitious materials and broaden the practical application scenarios of the materials, it’s firstly proposed the concept, that magnesium oxide as an admixture to inhibit pan-alkali in desulfurization gypsum-based cementitious materials. The macroscopic mechanical property changes of the materials were evaluated via compressive strength test, and the correlation mechanisms between microstructure and properties were thoroughly investigated using various characterization techniques. Specifically, XRD, SEM, FT-IR and NMR were used to reveal the changes of phase, micro-morphology, chemical bond and molecular structure, respectively. In addition, the pore structure characteristics of the materials were quantitatively characterized through BET and MIP analyses, which elucidates the regulatory mechanisms of porosity and pore size distribution in geopolymers. It’s revealed form the XRD and SEM tools that trace magnesium oxide dosage makes a large number of gel products formed, mainly including hydrated calcium aluminum silicate gels and hydrated magnesium silicate gels (C(M)-S-H). Furthermore, the 29Si MAS NMR results demonstrate that the GDM-9 cementitious material system is more conducive to the conversion of Q2, which enhances the polymerization degree of M-S-H silicone tetrahedron. And the polymerization degree increase inhibits the formation of harmful pores and reduces the content of free water, thus greatly reducing the phenomenon of alkalinity and enhancing the mechanical properties of the cementitious material. Compared with other DG-based geopolymers containing different magnesium oxide dosage, it’s illustrated that GDM-9 cementitious material system exhibits the lowest porosity of 36.18 %, largest compressive strength of 61.2 MPa and the flexural strength of 10.5 MPa. Moreover, visual observation of pan-alkali behavior presents that the surfaces of samples GDM-4.5 and GDM-9 exhibits a fine degree of pan-alkali, while sample GDM-0 presents the most severe pan-alkali, followed by sample GDM-18. In summary, the concept proposal, that the preparation of desulfurization gypsum based cementitious materials with the incorporation of trace magnesium provides promising alternative candidates for the solid waste treatment from the perspective of aquatic ecosystem protection and a novel idea for the inhibition of surface pan-alkali of desulfurization gypsum-based cementitious materials.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"470 ","pages":"Article 140634"},"PeriodicalIF":7.4,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143521274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Innovative two-step synthesis of ultrafine highly-carbonatable calcium silicate binder from waste carbide slag and silica","authors":"Songhui Liu ,&nbsp;Yibo Sun ,&nbsp;Genshen Li ,&nbsp;Shuqiong Luo ,&nbsp;Xuemao Guan ,&nbsp;Jianping Zhu ,&nbsp;Zhichao Liu ,&nbsp;Fazhou Wang","doi":"10.1016/j.conbuildmat.2025.140566","DOIUrl":"10.1016/j.conbuildmat.2025.140566","url":null,"abstract":"<div><div>This study presents an innovative two-step synthesis method for producing highly-carbonatable calcium silicate (CS) binder using waste carbide slag and silica. The process involves wet chemical synthesis of C-S-H precursors followed by calcination at various temperatures (300–1200°C). The resulting CS materials were characterized and subjected to carbonation curing to evaluate their CO₂ sequestration potential and mechanical properties. X-ray diffraction (XRD) and thermal analyses revealed the formation of β-CS at 800°C and its transformation to α-CS at 1200°C. The synthesized CS exhibited ultrafine crystallite sizes ranging from 20 to 77 nm, contributing to enhanced reactivity. Carbonation experiments demonstrated high CO₂ uptake, with samples calcined at 800°C achieving a remarkable 24 h carbonation strength of 160.41 MPa. Microstructural analysis using SEM and low-field NMR showed that the carbonation products formed a dense, interconnected structure with optimized pore distribution. The synergistic carbonation of residual C-S-H and β-CS, coupled with the small crystallite size, was found to be key in achieving high strength and CO₂ sequestration capacity. This research demonstrates the potential of the two-step synthesis method for producing highly reactive CS binders from industrial waste, offering a promising approach for CO₂ mitigation in the construction sector.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"470 ","pages":"Article 140566"},"PeriodicalIF":7.4,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143520360","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improvement of the thermal conductivity of micronized nanocellular poly(methyl-methacrylate) (PMMA) by adding infrared blockers","authors":"Ismael Sánchez-Calderón ,&nbsp;Félix Lizalde-Arroyo ,&nbsp;Judith Martín-de-León ,&nbsp;Miguel Ángel Rodríguez-Pérez ,&nbsp;Victoria Bernardo","doi":"10.1016/j.conbuildmat.2025.140522","DOIUrl":"10.1016/j.conbuildmat.2025.140522","url":null,"abstract":"<div><div>Micronized nanocellular polymers show great potential to be used as core materials for vacuum insulation panels due to their reduced thermal conductivity under vacuum. However, as a result of their nanocellular structure, these materials are characterized by thermal radiation contributions higher than 4 mW/(m·K). This work studies how to further enhance their thermal insulation behavior by adding infrared blockers to reduce thermal radiation. Three different opacifiers (titanium(IV) oxide, graphene nanoplatelets, and silicon carbide) are used in different contents (2.5, 5, 10, 15, and 20 wt%). The obtained powders are characterized to determine the apparent density, the particle size distribution, and the thermal conductivity. The addition of infrared blockers leads to an increase in apparent density which is also related to the opacifier’s particle size. For each infrared blocker, there is an optimum concentration to achieve the minimum thermal conductivity. Finally, compacted panels are produced to analyze their behavior as VIP cores by measuring thermal conductivity under vacuum conditions. A minimum thermal conductivity of 9.6 mW/(m·K) is obtained for the compacted panel containing 10 wt% of silicon carbide, a reduction of 2 mW/(m·K) regarding the sample without opacifier.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"470 ","pages":"Article 140522"},"PeriodicalIF":7.4,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143511570","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of NaOH and gypsum contents on the properties of cemented paste backfill using NaOH/gypsum-activated slag binders","authors":"Juanrong Zheng ,&nbsp;Pengpeng Bi ,&nbsp;Shasha Li ,&nbsp;Zhibin Yang","doi":"10.1016/j.conbuildmat.2025.140552","DOIUrl":"10.1016/j.conbuildmat.2025.140552","url":null,"abstract":"<div><div>In this study, the early age (⩽28 days) unconfined compressive strength (UCS) values of cemented paste backfill (CPB) samples with five different NaOH contents (i.e. 2 %, 4 %, 6 %, 8 % and 10 % by slag weight) and four different gypsum contents (i.e. 0 %, 10 %, 20 % and 30 % by binder weight) are investigated. The UCS development of several typical CPB samples from 3 days up to 180 days of curing was also examined, with the CPB sample using ordinary Portland cement (CPB-OPC) as the reference sample. The results demonstrate that the effects of NaOH and gypsum contents on the UCS of CPB samples using NaOH/gypsum-activated slag (NGAS) as binders depend on the NaOH-gypsum-slag interactions and their respective contents. CPB-N6AS-G20 samples with 6 wt% NaOH and 20 wt% gypsum achieved the highest UCS values at 3 days (2.1 MPa), 28 days (6.2 MPa) and 180 days (7.3 MPa) among all the samples studied, which is 1.4, 2.3 and 2.6 times higher than that of the reference sample (CPB-OPC), respectively. Therefore, the optimum NaOH and gypsum contents (ONG) in CPB matrices were found to be 6 wt% and 20 wt%, respectively. The presence of gypsum in CPB matrices was found to accelerate the hydration process of slag by facilitating the complete formation of ettringite (AFt) and promoting amorphous phase development at early ages (≤28 days), resulting in a denser microstructure and increased strength, and vice versa. The higher compressive strengths of CPBs was attributed to the higher content of amorphous hydration products. However, the combined effects of higher NaOH content (6 wt%) and high gypsum content (30 wt%) result in long-term strength loss of CPB samples. In conclusion, using NaOH/gypsum-activated slag binders with ONG in CPB demonstrates the potential to achieve higher early age strengths (at 3 days and 28 days) and long-term strength development while also offering significant economic and environmental benefits compared to NaOH-activated slag binders and OPC.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"470 ","pages":"Article 140552"},"PeriodicalIF":7.4,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143511789","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Earth composites as construction material reinforced with intensive agricultural fibres: Tomato, pepper, zucchini, cucumber, aubergine and polypropylene fibres","authors":"A. Cervilla-Maldonado,&nbsp;Valverde-Palacios I,&nbsp;R. Fuentes-García,&nbsp;F. Martín-Villegas","doi":"10.1016/j.conbuildmat.2025.140538","DOIUrl":"10.1016/j.conbuildmat.2025.140538","url":null,"abstract":"<div><div>The feasibility of lightweight construction materials by incorporating a waste that is difficult to recycle, based on waste from intensive agriculture: vegetable fibers and propylene, is presented. This innovative material consists of a mixture of Alhambra Formation soil (Granada, SE of Spain) reinforced with vegetable fibres from tomato, pepper, zucchini, cucumber, aubergine and polypropylene fibres. The fibres were used in the mixture at a ratio of 2.5 %, 5.0 %, 7.5 % and 10.0 %. These values were then compared with control test samples that did not contain any residues.</div><div>The compatibility of the fibres with the soil of the Alhambra Formation was then evaluated in terms of its physical-mechanical properties, specifically in relation to uniaxial compression and longitudinal deformation. Due to the highly hygroscopic nature of plant fibres, their absorption was measured and the techniques of presoaking and non-soaking the fibres before mixing them with the soil of the Alhambra Formation were investigated.</div><div>The results of the unconfined compression tests show that the increase in fibre volume leads to a significant decrease in compressive strength. The highest compressive strength from a residue ratio ≥ 7.5 % was achieved with the cucumber residue and the non-pre-soaking technique. This residue ratio reached an average value of 1.82 MPa, which is 4 % lower than the reference specimen without additives. Notwithstanding the decline in mechanical strength with elevated residue quantities, the resulting Alhambra Formation soil composite blended with a 7.5 % cucumber ratio may be regarded as a prospective candidate for implementation using the Projected Earth System technique.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"470 ","pages":"Article 140538"},"PeriodicalIF":7.4,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143520349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prediction model for grouting volume using borehole image features and explainable artificial intelligence","authors":"Yalei Zhe ,&nbsp;Kepeng Hou ,&nbsp;Zongyong Wang ,&nbsp;Shifei Yang ,&nbsp;Huafen Sun","doi":"10.1016/j.conbuildmat.2025.140626","DOIUrl":"10.1016/j.conbuildmat.2025.140626","url":null,"abstract":"<div><div>Grouting is widely used in various engineering projects, and accurate prediction of grout volume is of significant importance. Machine learning methods have been extensively applied in grout volume prediction, yet existing research still has limitations, such as the underutilization of unstructured data like images and the reliance on black-box models that lack interpretability and transparency, hindering practical application. This study collected field trial data from Yunnan Province, China, and introduced borehole image data, which had been overlooked in previous studies, along with explainable machine learning (XAI) methods to construct grout volume prediction models with high accuracy and interpretability. The results show that integrating image features into the dataset significantly enhanced the model's interpretability, prediction accuracy, and stability. The ensemble model, particularly Gradient Boosting Machine (GBM), achieved a Coefficient of Determination (R²) of 0.848, demonstrating strong explanatory power. SHAP analysis facilitated model interpretation and knowledge discovery, especially regarding the interactions between geological structural features and other features. The main contributions of this study are: (1) introduced and verified the validity of image data, expanding the research resources; (2) deepened the research in this field based on knowledge mining by interpretable machine learning; (3) provided new technical support for the actual grouting operation, as well as methodological references for subsequent research.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"470 ","pages":"Article 140626"},"PeriodicalIF":7.4,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143511572","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of thermal and mechanical performance of composite PCM mortar incorporated with graphene nanoplatelets","authors":"Syed Nayyar Raza Naqvi ,&nbsp;Muhammad Zeeshan Haider ,&nbsp;Xinghan Jin ,&nbsp;Jong Wan Hu","doi":"10.1016/j.conbuildmat.2025.140576","DOIUrl":"10.1016/j.conbuildmat.2025.140576","url":null,"abstract":"<div><div>The growing need for energy-efficient and sustainable construction materials has driven research into phase change material (PCM)-incorporated cementitious composites. However, directly incorporating PCM into cementitious materials presents several challenges, including leakage and reduced mechanical strength, which hinder their practical application. To address these limitations, shape stabilization techniques have been employed to improve the integration and stability of PCM in cement-based composites. Among these approaches, composite phase change materials (CPCM) have been developed by encapsulating PCM within a stable matrix, effectively preventing leakage and enhancing mechanical performance. However, PCM still exhibits limitations such as supercooling and low thermal conductivity, which reduces its heat transfer efficiency. This study investigates the impact of graphene nanoplatelets (GNPs) on the thermal and mechanical properties of CPCM incorporated mortar. CPCM was synthesized by impregnating PCM into activated carbon and coating it with a silica shell using the sol-gel process to prevent leakage. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) confirmed the thermal performance of CPCM, with enthalpies of 35.45 J/g and 33.89 J/g during melting and freezing, respectively. Mortars were prepared by replacing 50 % of fine aggregates with CPCM and incorporating GNPs at 0.05 %, 0.1 %, and 0.15 % by cement weight. While CPCM mortar exhibited a 12.78 % strength reduction, adding 0.1 % GNPs recovered 8.32 % of the lost strength. GNPs also enhanced thermal response, leading to a 1.52 °C higher temperature rise compared to reference mortar. Thus, the incorporation of GNPs significantly enhances thermal and mechanical performance of CPCM mortar, making it a promising solution for construction applications.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"470 ","pages":"Article 140576"},"PeriodicalIF":7.4,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143511576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing the characteristics of natural coir fiber yarns using biopolymer for textile reinforced cementitious composites","authors":"Nitish Kumar ,&nbsp;Prashant Rawat ,&nbsp;Ramesh Kannan Kandasami","doi":"10.1016/j.conbuildmat.2025.140427","DOIUrl":"10.1016/j.conbuildmat.2025.140427","url":null,"abstract":"<div><div>Textile reinforced mortar (TRM) composites typically comprise of high strength textiles (such as carbon, glass, and other synthetics fiber based textiles) embedded into cementitious matrix to improve the strength and stiffness of the resulting composites. However, with increasing global emphasis on sustainability and environmental consciousness has spurred the emergence of utilizing sustainable reinforcing materials such as natural plant fibers (in particular coir textile) in construction sectors. Nevertheless, natural coir fibers come with inherent drawbacks, including their hydrophilic nature and lower tensile strength/ stiffness. In addressing these challenges, coir yarns were fabricated by coating (one, two, and three layers) them in PLA (polylactic acid) suspension to obtain biocomposites. The average tensile strength of raw coir yarns (without polymer coating) is 42 MPa, which increased by 38% with one layer PLA-coating, 98% with two layers, and 107% with three layers, respectively. Additionally, the initial tangent modulus of raw coir yarns coated with three layers of PLA suspension improved by 121%. The changes in the mechanical characteristics is predominantly due to the improved material crystallinity after PLA-coating over the coir yarns. Further, the fractography analysis revealed the formation of tensile cracks on the surface of coir yarns exhibiting significant alterations corresponding to the number of PLA-layers applied. Finally, the optimally treated coir yarns were used as reinforcement in cement mortar along with pretensioning. The pretensioned PLA-coated coir yarns reinforced TRM composites enhanced the tensile strength by 133% and initial tangent modulus by 139% as compared to the reference specimens, while distributing the tensile stress uniformly (based on image analysis using DIC) along the length of the TRM composites.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":"470 ","pages":"Article 140427"},"PeriodicalIF":7.4,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143512280","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}