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Xanthan Gum Biopolymer for Uniform Dispersion of Halloysite Nanotubes to Enhance Micro- and Macroscopic Performance of Cementitious Composite: A Sustainable Alternative to Chemical Surfactants

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SSRN 2024年

作者： Rashidi, Yaser Li, Lily Korayem, Asghar Habibnejad School of Civil Engineering Iran University of Science and Technology Tehran Iran Centre of Smart Infrastructure and Digital Construction Department of Civil and Construction Engineering Swinburne University of Technology VIC3122 Australia

To fully exploit the potential of halloysite nanotubes (HNTs) in cement-based composites, stable ‎dispersion in cementitious environments is essential. While polycarboxylate ether (PCE) is ‎commonly used for this purpose, xanthan gum (XG) biopolymer offers a greener alternative, ‎providing stable and uniform dispersion. XG-modified HNTs show promise in enhancing the ‎engineering properties of these composites, but their impact on micro- and macroscopic ‎characteristics is still unclear. This study comprehensively assessed the influence of XG-modified ‎HNTs on hydration-phase assemblage, pore structure, microstructural morphology, as well as ‎compressive strength and transport properties in cementitious materials, and compared these results ‎to PCE-modified HNTs in similar systems. The results demonstrated that XG-modified HNTs ‎significantly outperformed PCE-modified HNTs by reducing calcium hydroxide (CH) content and ‎refining CH crystal structures. Additionally, XG-modified HNTs accelerated cement hydration ‎more effectively and promoted enhanced gel structure formation. Importantly, XG-modified HNTs ‎contributed to a greater reduction in pore size and porosity, a more uniform pore distribution, and ‎the formation of a more homogeneous cementitious matrix compared to PCE-modified HNTs. ‎Furthermore, after 90 days, the HNT-XG mixture exhibited increases in compressive strength ‎‎(14.3%), ultrasonic pulse velocity (7.1%), and electrical resistivity (13.3%) compared to the HNT-‎PCE mixture. Finally, the sustainability assessment revealed that using XG biopolymer results in ‎‎48.6% lower energy consumption, an 89.4% cleaner production process, and 16.3% lower ‎production costs compared to PCE. Consequently, XG biopolymer can be considered a superior ‎‎and sustainable alternative to chemical surfactants like PCE for the uniform dispersion of HNTs in ‎‎cementitious systems. © 2024, The Authors. All rights reserved.

关键词： Compressive strength

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An overview of soil–water characteristic curves of stabilised soils and their influential factors

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Journal of King Saud University - engineering Sciences 2022年第1期34卷 31-45页

作者： Eyo, E.U. Ng'ambi, S. Abbey, S.J. School of Energy Construction and Environment Faculty of Engineering Environment and Computing Coventry University Coventry United Kingdom Faculty of Environment and Technology Department of Geography and Environmental Management Civil Engineering Cluster University of the West of England United Kingdom

Since unsaturated soil conditions are normally experienced above the groundwater table, most treated or stabilised soils for roadworks, earth dams’ embankments, landfill sites, hydraulic barriers etc. could be regarded as existing in this region. The soil–water characteristic (or retention) curve (SWCC) is a useful conceptual tool by which an evaluation of unsaturated soil's property functions and corresponding macro-scale behaviour (strength, volume change, hydraulic conductivity, fluid flow, diffusivity, etc.) can be carried out. Hence, an examination of some of the various factors that could affect the hydraulic or water retention property of the stabilised soil is very vital both for laboratory studies and field practice. However, a thorough assessment of the water retention behaviour of stabilised soils can be understandably limited sometimes. This could be partly due to some of the perculiar conditions associated with soil preparation methods, soil type, soil-stabiliser mix proportion used, curing conditions, method of compaction, durability assessment modalities and other logistical issues surrounding either laboratory instrumentation or in-situ application. This article presents a critical and comprehensive review of these factors on the stabilised soil's water retention behaviour and also provides a systematic understanding of the mechanisms of stabilisation occurring at the micro- and macro-mechanical levels. Recommendations are also made to stimulate further discussions on the synthesis of SWCC of stabilised soils vis-à-vis factors influencing them with possible interpreted engineering behaviours such as shear strength and soil consolidation. © 2020 The Authors

关键词： Lime

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Experimental Investigation on Properties of Mortar Containing Waste Marble as Fine Aggregate 10th

Experimental Investigation on Properties of Mortar Containin...

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10th EAI International Conference on Advancements of Science and technology , EAI ICAST 2022

作者： Yehualaw, Mitiku Damtie Eshetie, Akelilu Musback Yifru, Begashaw Worku Vo, Duy-Hai Faculty of Civil and Water Resources Engineering Bahir Dar Institute of Technology Bahir Dar University Bahir Dar Ethiopia Department of Construction Technology and Management Woldia Institute of Technology Woldia University Woldia Ethiopia Department of Civil Engineering University of Technology and Education The University of Danang Hai Chau Da Nang Viet Nam

ISBN: (纸本)9783031336096

The increased demand for river sand creates additional environmental problems in the form of deepening river beds leading to riverbank erosion, disturbances to aquatic life, and air and water pollution. On the other hand, a high volume of industrial production has generated a significant amount of waste materials, which have a huge impact on the environment. In this regard, the speedy growth of the marble industry introduces concerns about the environment through producing waste, which is very polluting due to its alkaline nature and imposes serious health threats to the environs. This study aims to investigate the property of mortal-containing waste marble as a fine aggregate substitution. To this end, 5 series of mixes with a total of 180 mortar specimens were prepared. Waste marble powder replaced fine aggregate at 10%, 20%, 30%, and 40% by weight, in all mixtures, water to cement and sand to cement ratio was kept constant at 0.5 and 1:2.75, respectively. The fresh properties of the mortar mixtures were determined by the flow table. Tests on hardened mortar include compressive, flexural, split tensile strength, water absorption, water permeability, and sulfate resistance was investigated. The result indicated that adding waste marble with a lower percentage (i.e., 10–20%) improves workability and had better mechanical properties than the control mixes. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG.

关键词： Mortar

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Numerical investigation of pile responses induced by adjacent tunnel excavation in spatially variable clays

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Underground Space 2022年第5期7卷 911-927页

作者： Xin Gu Fuyong Chen Wengang Zhang Qi Wang Hanlong Liu School of Civil Engineering Chongqing UniversityChongqingChina Key Laboratory of New Technology for Construction of Cities in Mountain Area Chongqing UniversityChongqingChina National Joint Engineering Research Center of Geohazards Prevention in the Reservoir Areas Chongqing UniversityChongqingChina

The pile responses induced by adjacent tunnel excavation have been a hot research topic in geotechnical *** excavation may exert disturbance to the surrounding soil mass and then influence the adjacent pile *** this paper,the random finite difference analysis considering the spatial variations of soil properties is conducted to explore the effect of tunnel excavation on the adjacent pile response by varying the distance of pile away from the tunnel centerline(D),the pile length(L),the pile diameter(d_(p)),the tunnel depth(h),and the anisotropic ratio between the horizontal and the vertical scales of fluctuation(δ_(x)/δ_(y)).A set of pile response curves are developed to assess the influence of tunnel excavation on the adjacent passive pile foundations in spatially variable clays and provide guidelines for the tunnel excavation in the complex constructed environment.

关键词： Pile response Tunnel excavation Random field Spatially variable clays Random finite difference analysis

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Experimental investigation of engineered geopolymer composite for structural strengthening against blast loads

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Defence technology（防务技术） 2024年第2期32卷 496-509页

作者： Shan Liu Chunyuan Liu Yifei Hao Yi Zhang Li Chen Zhan Li Key Laboratory of Coast Civil Structure Safety of Ministry of Education Tianjin UniversityTianjin 300072China Tianjin Key Laboratory of Prefabricated Buildings and Intelligent Construction Hebei University of TechnologyTianjin 300400China Institute of Defense Engineering AMSPLABeijing 100850China Engineering Research Center of Safety and Protection of Explosion&Impact of Ministry of Education Southeast UniversityNanjing 211189JiangsuChina State Key Laboratory of Disaster Prevention&Mitigation of Explosion&Impact Army Engineering University of the PLANanjing 210007JiangsuChina

The recent increase in blast/bombing incidents all over the world has pushed the development of effective strengthening approaches to enhance the blast resistance of existing civil *** geopolymer composite(EGC)is a promising material featured by eco-friendly,fast-setting and strain-hardening characteristics for emergent strengthening and ***,the fiber optimization for preparing EGC and its protective effect on structural elements under blast scenarios are *** this study,laboratory tests were firstly conducted to evaluate the effects of fiber types on the properties of EGC in terms of workability,dry shrinkage,and mechanical properties in compression,tension and *** experimental results showed that EGC containing PE fiber exhibited suitable workability,acceptable dry shrinkage and superior mechanical properties compared with other types of *** that,a series of field tests were carried out to evaluate the effectiveness of EGC retrofitting layer on the enhancement of blast performance of typical *** tests include autoclaved aerated concrete(AAC)masonry walls subjected to vented gas explosion,reinforced AAC panels subjected to TNT explosion and plain concrete slabs subjected to contact *** was found that EGC could effectively enhance the blast resistance of structural elements in different *** AAC masonry walls and panels,with the existence of EGC,the integrity of specimens could be maintained,and their deflections and damage were significantly *** plain concrete slabs,the EGC overlay could reduce the diameter and depth of the crater and spallation of specimens.

关键词： Engineered geopolymer composites Fiber optimization Strengthening material Blast resistance Masonry wall Reinforced AAC panel Plain concrete slab

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Concrete 3D Printing of Shape-Optimized Lattice Beams Incorporating Nature-Inspired Patterns

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Journal of Architectural engineering 2025年第3期31卷

作者： Santhosh, S. Gokul Raphael, Benny Santhanam, Manu Building Technology and Construction Management Division Dept. of Civil Engineering IIT Madras Chennai600036 India

The advent of concrete three-dimensional (3D) printing has opened new frontiers in architectural design, offering unprecedented geometric freedom and potential for material efficiency. While 3D-printed lattice beams are known for minimizing material usage, most current research has focused only on traditional repetitive patterns. Organic forms and patterns found in nature have not been deeply explored for 3D-printed concrete lattice beams. This paper investigates the potential material savings of using nature-inspired Voronoi patterns in concrete 3D-printed beams, comparing them with conventional patterns in shape-optimized lattice beams. 3D-printable lattice beams with various infill patterns are generated using a parametric design system and optimized using genetic algorithm. The design system varies geometric model parameters within specified ranges, and each configuration is analyzed using a finite-element software. The analysis results are used by the genetic algorithm to optimize the member sizes, orientation, and other case-specific geometric parameters (depending on the type of beam) to minimize material usage, while satisfying the relevant constraints. A small-scale beam of 700 mm span is 3D-printed and tested under center-point loading to validate the system, demonstrating practical feasibility. The findings indicate that concrete 3D printing can effectively incorporate nature-inspired patterns in shape-optimized structures, opening new avenues for architectural design and material resource efficiency. © 2025 American Society of civil Engineers.

关键词： Shape optimization

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Skin Friction Increases Associated with Pipe-Jacking Stoppages Modelled Using Direct Shear Interface Tests

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SSRN 2024年

作者： McCabe, Bryan A. O'Dwyer, Kevin G. Sheil, Brian B. Civil Engineering School of Engineering University of Galway Ireland Laing O’Rourke Centre for Construction Engineering & Technology Department of Civil Engineering University of Cambridge United Kingdom

In long pipe-jacking drives used for installing utility pipelines, field experience has shown that transient peaks in skin friction arise upon recommencement of jacking after stoppages;these forces are often very large and difficult to predict, presenting a significant risk for contractors. In this paper, the problem is replicated in the laboratory using direct shear interface tests with a concrete specimen in one half of the apparatus and various sand/bentonite slurry mixtures in the other. Once critical state conditions were reached in these tests, stoppages of various durations (from 30 mins up to ≈2 weeks) were incorporated and the increase in shear stress upon recommencement of shearing was noted. The experimental results showed that these increases are dependent on bentonite slurry content, and there appears to be a threshold stoppage duration beyond which the skin friction increase appears to plateau, suggestive of a time-limited process within the bentonite. Shearometer tests measuring the gel strength of aged bentonite slurry samples, in addition to small and erratic (in time) consolidation magnitudes during direct shear test stoppages combine to suggest that bentonite thixotropy is, at least in part, the mechanism behind the stoppage-induced skin friction increases. A simple model capturing this behaviour provided a safe upper bound to the stoppage-induced skin friction increases extracted from a selection of field data, offering much better jacking force predictions than standard prediction models used in industry. © 2024, The Authors. All rights reserved.

关键词： Bentonite

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Influence of Erosion Induced by NaCl on the Mechanical Performances of Alkali-Activated Mineral Admixtures

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Fluid Dynamics & Materials Processing 2023年第9期19卷 2385-2398页

作者： Jing Yu Jie Ren Guangming Shen Weixiang Sun Hui Wang Department of Architectural Engineering Ningbo PolytechnicNingbo315000China Technology and Performance Management Department China Construction Infrastructure Corp.Ltd.Beijing10029China Chief Engineer’s Office Jiuzhou Engineering Design Co.Ltd.Zhengzhou451162China School of Civil Engineering and Geographic Environment Ningbo UniversityNingbo315000China

In this paper,the inﬂuence of NaCl freeze-thaw(F-T)cycles and dry-wet(D-W)alternations on theﬂexural,com-pressive and bonding strengths of alkali-activatedﬂy ash(FA)and a blast furnace slag powder(BFS)is *** considered NaCl concentration is 3%.The effect of polypropyleneﬁbers on the mechanical strengths is also *** electron microscopy(SEM),thermogravimetry(TG)and X-ray diffraction(XRD)are selected to discern the mechanisms underpinning the NaCl-induced *** obtained results indicate that the best results in terms of material resistance are obtained with admixtures containing 60%BFS and 40%FA in terms of mass ratio and 3%polypropyleneﬁbers in terms of volume *** maximum rates of decrease of theﬂexural,compressive and bonding strengths after 300 NaCl F-T cycles are 21.5%,20.3%and 22.6%,*** corresponding rates of decrease due to NaCl D-W alternations are 28.1%,26.1%and 31.5%,*** TG curves show that the alkali-activating activity of BFS is higher than that of ***,in theﬁrst case,the microstructure of the hydration products is more *** results also show that NaCl F-T cycles lead to increasing cracks in the alkali-activated BFS.

关键词： Mechanical performances alkali-activated NaCl dry-wet alternations NaCl freeze-thaw cycles microstructure

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A review on concrete's durability in India – Framework for performance-based approach

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Materials Today: Proceedings 2022年 60卷 545-551页

作者： Sugandhini, H.K. Shriraksha Sivadas, Nivedita Nayak, Gopinatha Shetty, Kiran K. Department of Civil Engineering Manipal Institute of Technology Manipal Academy of Higher Education Karnataka Manipal576104 India M. Tech. in Construction Engineering and Management Manipal Institute of Technology Manipal Academy of Higher Education Karnataka Manipal576104 India

Concrete is considered the most known and commonly utilized building material because of its minimal expense, flexibility, and adaptability. When exposed to hostile chloride or carbonation-induced conditions, reinforced concrete (RC) constructions have deteriorated before their projected service life. The deterioration is due to the wrong understanding that the concrete will last long enough if it only meets the necessary strength criteria. This presumption ignores the variations caused by the site activities such as placing, consolidating, finishing, and curing of concrete. In other words, the concrete used in compressive strength specimens bears little correlation to the concrete used in actual structures. This extensive review provides a comprehensive overview of the progress towards performance-based requirements for ensuring the long-term durability of RC structures. It also presents the evolution of codal provisions in enhancing durability and the acceptance criteria of various durability indicators for concrete mixes. © 2022

关键词： Durability

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Experimental investigation on flow-induced vibration of flexible riser transporting spiral flow in deep sea mining 34th

Experimental investigation on flow-induced vibration of flex...

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34th International Ocean and Polar engineering Conference, ISOPE 2024

作者： Zhang, Jiayu Chen, Nianzhong Sævik, Svein Ye, Naiquan School of Civil Engineering Tianjin University Tianjin China State Key Laboratory of Hydraulic Engineering Intelligent Construction and Operation Tianjin University Tianjin China Department of Marine Technology Norwegian University of Science and Technology Trondheim Norway Department of Pipelines Risers and Umbilicals SINTEF Ocean Trondheim Norway

ISBN: (纸本)9781880653784

An experimental study is conducted within a large-scale simulated deepsea mining transport system and spiral flow generation system to shed some light on the multiphase FIV and the correlation with the dynamic behavior of the riser caused by the spiral flow. Experimental results show that the riser transporting spiral flow is significantly affected by nonlinear effects. Furthermore, the particles were uniformly distributed inside the riser due to the circumferential effects of the spiral flow, and the occurrence of internal flow density fluctuations was reduced. As a consequence, riser vibrations were suppressed within a certain range of flow velocity and density range. © 2024 by the International Society of Offshore and Polar Engineers (ISOPE).

关键词： Flow velocity

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