CONSTRUCTION AND BUILDING MATERIALS
·
2024
·
IF 7.4
Zhicheng Gu,Peiyuan Chen,Cheng Wang,Aiguo Wang,Yonghui Wang,Peng Qian,Xiangkun Li
The hydrophobicity nature of the waste carbon fiber felt (WCF) surface results in the formation of a weak interface with the paste during the curing process of WCF concrete, which seriously affects the performance of WCF concrete and the reuse of WCF. To address this problem, this paper utilized polydopamine (PDA) for the functionalization of WCF to enhance bonding between WCF and paste. The wettability , Ca 2+ complexation, and functional groups of PDA coating on WCF were analyzed by contact angle, ICP-OES, and XPS , respectively. Additionally, the effects of incorporating PDA-functionalized WCF on the flowability , compressive strength , hydration kinetics , pore structure , water absorption capillary , and SEM of mortars were tested. Experimental results showed that the PDA coating improved the wettability of WCF and enhanced the flowability of WCF mortar. What's more, the PDA coating could chelate Ca 2+ and promote the formation and deposition of hydration products on the WCF surface, resulting in a denser interfacial transition zone (ITZ). Compared with ordinary WCF mortar, the compressive strength of the PDA-modified WCF mortar was increased by 18% at 28d. Furthermore, the capillary water absorption of the modified group mortar was also decreased by up to 13%, significantly enhancing the durability of mortars. This paper presents a green and simple bio-inspired method to strengthen the ITZ between WCF and paste, which is fundamentally different from the traditional modification methods, and also offers a theoretical basis and technical foundation for the sustainable utilization of WCF.
研究领域:
材料科学
·
土木工程
✓ 已验证
产品关联
DOI
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2025
·
IF 8
Chengyan Hou,Haibo Zhang,Hucheng Chai,Chunwei Wang,Xu Yang
Aggregates account for approximately 65–75 % of the concrete volume, significantly influencing its performance. However, the effect of aggregate surface wettability on concrete performance is frequently neglected. In this study, 12 types of aggregates were prepared with surface contact angles ranging from 34.0° to 77.9°, using a silane coupling agent (SCA) to modify quartz sand. The effects of contact angle on the fluidity and mechanical performance of mortar, as well as the performance of the interface transition zone (ITZ), were investigated. Further analysis explored the mechanism by which the contact angle affects mortar performance. The results showed that the optimal performance of mortar was achieved at a contact angle of 60.8°, resulting in flexural and compressive strengths of 8.8 MPa and 59.1 MPa, respectively-representing increases of 9 % and 19.5 % compared to unmodified aggregates. Additionally, microscopic tests confirmed that the mechanical performance of the ITZ improved by 53.2 %, while its porosity decreased by 19.2 %, leading to enhanced interfacial bonding performance. However, when the contact angle exceeds 60.8°, the mortar performance gradually decreases. Based on these findings, this study proposed a mechanism for the influence of aggregate surface contact angle on mortar performance, providing a new way to improve the quality of cement concrete and offering important theoretical significance and practical value.
研究领域:
土木工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2025
·
IF 8
Ming Zhang,Pengfei Hu,Shangyu Sun,Jie Yao,Yubo Sun,Jing Zhong
The global surge in construction has intensified demand for natural silica sand (SS), causing shortages due to unsustainable extraction. This study explores the potential of using desert sand (DS) as an alternative to SS in producing ultra-high-performance alkali-activated concrete (UHPAAC), emphasizing the interactions between aggregates and the binding matrix. DS demonstrated a smoother surface morphology, finer particles, and a narrower gradation compared to SS. Substituting SS with DS at varying volume ratios improved the concentration of several elements in the pore solution of fresh mixtures. Samples with 10 vol% DS achieved the highest compressive strength, about 20 % higher than the SS reference mix. However, higher DS content reduced mechanical performance. Investigations of reaction products and microstructural characteristics revealed changes in the binder phase, including a lower Ca/Si ratio and improved local elastic modulus when DS was incorporated. Additionally, the smaller grain sizes of DS created numerous interfaces with the binding matrix, resulting in a more porous microstructure and declined micromechanical properties in the interfacial transition zone (ITZ) compared to SS. Nevertheless, the strategic incorporation of DS as a partial replacement for SS enhances both compressive and flexural strength while simultaneously reducing the environmental impact of UHPAAC production.
研究领域:
土木工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2018
·
IF 3.485
Junpeng Mei,Hongbo Tan,Hainan Li,Baoguo Ma,Xiaohai Liu,Wenbin Jiang,Ting Zhang,Xin Li
Generally, high volume fly ash would considerably reduce the early strength of cement-based materials, and because of this disadvantage, the added amount of fly ash in steam-cured precast concrete is very limited. In this study, an attempt to enhance the early strength of steam-cured cement-high volume fly ash (40 wt%, CHVFA) system has been done with addition of nano-SiO 2 (NS) and sodium sulfate (SS). Effect of these two chemicals on hydration, pore structure, and microstructure of interfacial transition zone (ITZ) were investigated. The results show that both NS and SS can improve the compressive strength, and the reason is mainly because these two chemicals can accelerate the hydration of cement minerals and can also hasten the pozzolanic reaction of fly ash. By contrast, because of the high activity of pozzolanic reaction and the filling and nucleation effects, NS has much stronger effect on refining pore structure and promoting the hydration of cement; while SS can exert much stronger effect on accelerating the hydration of fly ash than that of NS. An interesting thing can also be seen that with co-doped NS-SS, the enhancement in compressive strength is much stronger than that of the sum of these single systems with the same dosage, indicating that NS and SS can exert the synergistic effect; this effect is involved in the accelerated hydration of CHVFA, the refined pore structure, and the improved microstructure of ITZ. Such results would be expected to provide guidance on enhancing the early strength of steam-cured precast concrete with high volume fly ash in practical engineering.
研究领域:
土木工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Buildings
·
2025
·Vol. 15
·期 23
·4246
·
IF 3.1
Lei Chen,Yihang Hu,Yujie Mao,Min Qiao,Changcheng Li,Jian Zhang,Yang Chu,Xin Shu
The low flexural strength and high brittleness of cement-based materials greatly compromise their safety, durability, and service life. In situ polymerization is a promising strategy for enhancing the toughness of cement-based materials. However, the underlying mechanisms responsible for this mechanical improvement remain insufficiently understood. This study introduces acrylamide (AM) monomer into a cement matrix, where in situ polymerization forms a strong polymer–cement network, demonstrably enhancing mechanical performance. The factors influencing this mechanical enhancement were investigated across multiple scales using techniques including nanoindentation, crack width measurement, solid-state silicon nuclear magnetic resonance (29Si NMR), thermogravimetric analysis (TGA), and so on. This research confirms that in situ polymerization influences silicate chain length (from 3.405 to 3.714) and pore structure at the nanoscale, modifies the morphology of hydration products, enhances the hardness of the interfacial transition zone (0.025 ± 0.002 to 0.055 ± 0.004 GPa) at the microscale, and reveals that at monomer concentrations below 1 wt%, both the compressive and flexural strengths of the cement-based material are improved, with 28d compressive and flexural strength increasing by 23.86% and 26.58%, respectively. Conversely, higher monomer dosages lead to a simultaneous reduction in both compressive and flexural strengths. Consequently, through tracking the hydration process on the mechanical properties of cement-based materials across multiple scales, this study provides deeper insights into the in situ polymerization system and offers an effective strategy for the design and preparation of high-performance concrete.
✓ 已验证
产品关联
DOI
高影响因子
Alexandria Engineering Journal
·
2024
·
IF 6.2
Hong Zhang,Ming Chen,Tiantian Liang,Zanpeng Zhang,Changhui Yang
The use of nanocarbon materials to enhance the toughness of fragile cementitious materials has attracted increasing attention for investigation. This study examines the effects of incorporating graphene oxide (GO) into NaOH-activated slag (AAS) pastes and mortars, focusing on workability, phase composition, mechanical properties, and the local mechanical properties of the interfacial transition zone (ITZ) between sand and paste. The experimental results indicate that the addition of GO decreases the flowability of NaOH-AAS pastes, with noticeable aggregation at concentrations above 0.03 wt%. Furthermore, GO enhances the hydration degree of ground granulated blast furnace slag (GGBS), leading to an increased amount of C-A-S-H gel without introducing new phases. In terms of macro performance, incorporating 0.03 wt% GO significantly improves the compressive and flexural strengths of NaOH-AAS mortars by 10.6 % and 17.9 %, respectively. Additionally, the presence of GO reduces the ITZ thickness from 30 to 15 micrometres in NaOH-AAS mortars, which likely contributes to the enhanced mechanical performance.
研究领域:
材料科学
·
水泥基材料
·
纳米复合材料
·
建筑材料化学
·
界面工程
✓ 已验证
DOI
高影响因子
Coatings
·
2024
·Vol. 14
·期 12
·1482
·
IF 2.9
Tusheng He,Wei Xie,Feng Wang,Zi Yu,Fang Xu,Jinhui Li,Yitong Deng,Qingjun Ding,Yan Hao,Wei Xu,Haibin Yu
To further enhance the abrasion resistance of UHPC in demanding abrasion environments, this study investigated the effects of graphene oxide (GO) on the workability, mechanical properties, and abrasion resistance of UHPC. Utilizing 27Al Nuclear Magnetic Resonance (NMR), 29Si NMR, microhardness, and BET analysis, the study analyzed the mechanisms through which GO influences UHPC’s microstructure in terms of abrasion resistance. Additionally, molecular dynamics simulations were employed to examine the mechanisms by which GO enhances UHPC’s abrasion resistance at the nano and micron scale. The findings show that an optimal amount of GO can improve the mechanical properties and abrasion resistance of UHPC. When 0.03% of GO (by cementitious material mass) was incorporated, the impact on workability was minimal, yet compressive strength increased by approximately 1.80%, flexural strength by 3.02%, impact wear resistance by 1.78%, the abrasion loss rate decreased by 10.01%, ultimate impact energy increased by 1.76%, and the toughness index improved by 10.10%. GO enhances abrasion-resistant UHPC primarily by increasing hydration, refining pore structure, and improving the microstructure of the interfacial transition zone. While GO increases the hydration degree of the UHPC matrix, it does not alter the silicate chain in C-A-S-H gels within the paste. Additionally, the incorporation of graphene oxide can refine the pore structure of the UHPC cement paste and improve the microstructure of the interfacial transition zone (ITZ) between the aggregate and the cement paste. The molecular dynamics simulation reveals that, under abrasive forces, GO forms strong, stable chemical bonds with the C-A-S-H base atoms, significantly enhancing the abrasion resistance of C-A-S-H.
研究领域:
建筑材料
·
土木工程材料
·
纳米复合材料
·
混凝土耐久性
·
微观结构表征
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2023
·Vol. 30
·期 16
·48248-48259
·
IF 5.8
Pan Zewen,Tang Changyuan,Cao Yingjie,Xuan Yingxue,Zhou Qianyi
The sources and distribution characteristics of three phenolic endocrine-disrupting compounds (EDCs), e.g., alkylphenols (APs) (including nonylphenols (NPs) and 4-t-octylphenol (OP)) and Bisphenol A (BPA), were investigated in the rivers of the Pearl River Delta Region (PRDR) with complex land-use types. The mean concentrations of NPs, OP, and BPA in river water including wet and dry seasons were 87, 6, and 74 ng/L in the agricultural regions ( n = 10), 135, 7, and 61 ng/L in the transitional regions ( n = 8), and 249, 15, and 152 ng/L in the urban regions ( n = 28). Contents of NPs and BPA were high in the river sediments (ranged from 7 to 3048 ng/g and 2 to 271 ng/g, respectively). Equilibrium analysis results suggested that sediment release was not the main source of the river EDCs. Principal component analysis (PCA) showed that sewage was the major source of EDCs in the dry season, while the leaching effect of rainfall on the agricultural soils, urban roads, and commercial products was an important source in the wet season. Furthermore, the ratio of APs and total concentration of phenolic EDCs (ΣEDCs) was used to characterize the agricultural regions and urban regions in the PRDR. The ratio was less than 0.6 in the agricultural regions while the ratio was large than 0.6 in the dry season and less than 0.6 in the wet season in urban regions. BPA and NPs in transitional region and urban region had small/medium potential risk to aquatic organisms.
研究领域:
环境科学
·
化学工程
·
水资源管理
·
生态毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）