Magazine of Concrete Research最新文献

Moment redistribution capacity in prestressed concrete continuous beams 预应力混凝土连续梁的弯矩再分布能力

IF 1.8 4区工程技术

Magazine of Concrete Research Pub Date : 2024-08-10 DOI: 10.1680/jmacr.24.00138

Da Luo, Bing Li

{"title":"Moment redistribution capacity in prestressed concrete continuous beams","authors":"Da Luo, Bing Li","doi":"10.1680/jmacr.24.00138","DOIUrl":"https://doi.org/10.1680/jmacr.24.00138","url":null,"abstract":"In prestressed concrete continuous beams, building code provisions often allow for a reduction in the moment at a critical section (calculated through elastic analysis). This reduction is permitted as long as the moments in all other sections are adjusted to maintain equilibrium and support the designated loads. However, the allowable moment redistribution percentage (MRP) for prestressed concrete beams (PCBs) remains a topic of debate. Many codes currently assign a similar MRP limitation to both PCBs and reinforced concrete members. This approach might be over-simplistic for PCBs due to their unique behaviour. This paper proposes a method for identifying the maximum available MRP. An in-depth study was conducted on the maximum available MRP of PCBs based on calibrated finite element models. The results show that the parameters such as passive reinforcement ratio, steel yield strength, slenderness ratio, eccentricity of prestressing tendons, concrete grade, and load pattern, which were not considered in the codes, influence the maximum available MRP to an extent. Using the same permissible MRP as reinforced concrete beams may be inappropriate. Finally, an equation is proposed to estimate the maximum available MRP for PCBs.","PeriodicalId":18113,"journal":{"name":"Magazine of Concrete Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141919411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Evaluation of self-healing in reactive powder concrete with urea-formaldehyde/epoxy microcapsules 评估含有脲醛/环氧微胶囊的活性粉末混凝土的自愈合能力

IF 1.8 4区工程技术

Magazine of Concrete Research Pub Date : 2024-08-10 DOI: 10.1680/jmacr.23.00302

H. Khosravi, Effat Mehrazin, M. Lezgy-Nazargah

{"title":"Evaluation of self-healing in reactive powder concrete with urea-formaldehyde/epoxy microcapsules","authors":"H. Khosravi, Effat Mehrazin, M. Lezgy-Nazargah","doi":"10.1680/jmacr.23.00302","DOIUrl":"https://doi.org/10.1680/jmacr.23.00302","url":null,"abstract":"The use of microcapsules as a preservative agent for healing materials has led to a great revolution in the repair of materials. Microcapsules have been used in medicine, agriculture, metallurgy, and mechanics. In civil engineering applications, microcapsules are usually used for the self-healing of concrete, asphalt and cementitious materials. Concrete and cement are widely used in civil engineering and they are distinguished as the predominant construction materials worldwide. The objective of this study is to design and produce urea-formaldehyde microcapsules for the recovery of reactive powder concrete (RPC). The obtained results demonstrated that the RPC specimens containing microcapsules exhibit different behaviors, compared to RPC specimens without microcapsules. For all RPC specimens containing microcapsule, measured values of strengths were lower than specimens without microcapsules. The minimum reduction in the compressive strength was observed in specimens with microcapsules content ranging from 4% to 6% by cement weight. The healing ratio of the compressive strength increased by increasing the weight percentage of microcapsules. Scanning electron microscope (SEM) imaging and energy dispersive spectroscopy (EDS) analysis were used to observe the process of crack healing. The SEM/EDS results showed that cracks are filled by healing products.","PeriodicalId":18113,"journal":{"name":"Magazine of Concrete Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141920604","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Moment redistribution capacity in prestressed concrete continuous beams 预应力混凝土连续梁的弯矩再分布能力

IF 1.8 4区工程技术

Magazine of Concrete Research Pub Date : 2024-08-10 DOI: 10.1680/jmacr.24.00138

Da Luo, Bing Li

{"title":"Moment redistribution capacity in prestressed concrete continuous beams","authors":"Da Luo, Bing Li","doi":"10.1680/jmacr.24.00138","DOIUrl":"https://doi.org/10.1680/jmacr.24.00138","url":null,"abstract":"In prestressed concrete continuous beams, building code provisions often allow for a reduction in the moment at a critical section (calculated through elastic analysis). This reduction is permitted as long as the moments in all other sections are adjusted to maintain equilibrium and support the designated loads. However, the allowable moment redistribution percentage (MRP) for prestressed concrete beams (PCBs) remains a topic of debate. Many codes currently assign a similar MRP limitation to both PCBs and reinforced concrete members. This approach might be over-simplistic for PCBs due to their unique behaviour. This paper proposes a method for identifying the maximum available MRP. An in-depth study was conducted on the maximum available MRP of PCBs based on calibrated finite element models. The results show that the parameters such as passive reinforcement ratio, steel yield strength, slenderness ratio, eccentricity of prestressing tendons, concrete grade, and load pattern, which were not considered in the codes, influence the maximum available MRP to an extent. Using the same permissible MRP as reinforced concrete beams may be inappropriate. Finally, an equation is proposed to estimate the maximum available MRP for PCBs.","PeriodicalId":18113,"journal":{"name":"Magazine of Concrete Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141919896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Influence of soil contaminated water on clogging phenomenon of different void based pervious concrete 土壤污染水对不同空隙透水混凝土堵塞现象的影响

IF 1.8 4区工程技术

Magazine of Concrete Research Pub Date : 2024-07-24 DOI: 10.1680/jmacr.24.00009

Nagesh Pratap Singh, G. Santha Kumar, S. Ganesh Kumar

{"title":"Influence of soil contaminated water on clogging phenomenon of different void based pervious concrete","authors":"Nagesh Pratap Singh, G. Santha Kumar, S. Ganesh Kumar","doi":"10.1680/jmacr.24.00009","DOIUrl":"https://doi.org/10.1680/jmacr.24.00009","url":null,"abstract":"In many circumstances, water passing through pervious concrete (PC) is contaminated with soil sediments. Hence, in such cases, the clogging of PC affects its functional characteristics and service life conditions. The clogging behaviour of different void based PC under the influence of soil-contaminated water is not yet clearly understood. This study explores the effect of using three different kinds of soil-contaminated water such as sand contaminated water, clayey silt contaminated water, and a mixture of sand and clayey silt contaminated water on the pore clogging phenomenon of different void based PC. Three different concentrations of soil contaminated water for each kind of PC were employed for carrying out clogging process in this present study. The clogging process was executed until reaching the minimum permeability level of the PC. This paper also elucidates the effectiveness of the washing process on the de-clogging behaviour of each clogged PC. In addition to this, various characteristics of different void-based PC, such as, strength, permeability, macroscopic pores distribution, and leaching parameters, were assessed. The outcomes of the experimental research work disseminate consensus behaviour of PC that would be helpful to provide a conceivable solution to develop the desirable performance of PC for wide applications.","PeriodicalId":18113,"journal":{"name":"Magazine of Concrete Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141809075","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Influence of polycarboxylate superplasticizer and polyacrylamide on mirror effect of fair-faced concrete 聚羧酸盐超塑化剂和聚丙烯酰胺对清水混凝土镜面效果的影响

IF 1.8 4区工程技术

Magazine of Concrete Research Pub Date : 2024-07-22 DOI: 10.1680/jmacr.24.00122

Hongxiang Zheng, Weizhun Jin, Liang Wang, Binbin Na, Zhengxiang Lin, Jinghui Zhang, Qinghua Huang, Linhua Jiang

{"title":"Influence of polycarboxylate superplasticizer and polyacrylamide on mirror effect of fair-faced concrete","authors":"Hongxiang Zheng, Weizhun Jin, Liang Wang, Binbin Na, Zhengxiang Lin, Jinghui Zhang, Qinghua Huang, Linhua Jiang","doi":"10.1680/jmacr.24.00122","DOIUrl":"https://doi.org/10.1680/jmacr.24.00122","url":null,"abstract":"This work successfully prepared fair-faced concrete with mirror effect. The gray value standard deviation, porosity, crack rate and glossiness of the concrete surface were used to characterize the apparent quality of fair-faced concrete. The effect of polycarboxylate superplasticizer and polyacrylamide viscosity-modifying admixture on mirror effect of fair-faced concrete was investigated. The changes of hydration products and microstructure of fair-faced concrete were monitored by the measurements of X-ray diffraction (XRD), thermogravimetric analysis (TG), scanning electron microscopy (SEM) and mercury intrusion porosity (MIP), and the potential mechanism was analyzed. The results indicate that the polyacrylamide reduces the number and size of Ca(OH)2 and change the morphology of Ca(OH)2 crystals from large-size parallel stacking state to small-size edge corrosion structure. The polyacrylamide can refine the pore size of concrete, the most probable pore size at the optimum dosage is 13.73 nm, which is much lower than that at other dosages. The usage of the polycarboxylate superplasticizer will introduce air, which has adverse effect on the concrete surface. But polycarboxylate superplasticizer can also improve the flowability of concrete and make bubbles easy to discharge. The combined action of polycarboxylate superplasticizer and polyacrylamide contributes the fair-faced concrete for better mirror effect.","PeriodicalId":18113,"journal":{"name":"Magazine of Concrete Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141816520","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Performance of precursor characteristics in the realization of geopolymer concrete: a review 前驱体特性在实现土工聚合物混凝土过程中的表现：综述

IF 1.8 4区工程技术

Magazine of Concrete Research Pub Date : 2024-07-18 DOI: 10.1680/jmacr.24.00120

Saswat Dwibedy, Suraj Kumar Parhi, Soumyaranjan Panda, S. K. Panigrahi

{"title":"Performance of precursor characteristics in the realization of geopolymer concrete: a review","authors":"Saswat Dwibedy, Suraj Kumar Parhi, Soumyaranjan Panda, S. K. Panigrahi","doi":"10.1680/jmacr.24.00120","DOIUrl":"https://doi.org/10.1680/jmacr.24.00120","url":null,"abstract":"Geopolymer is an inorganic polymer whose formation is based on the reaction between the precursors and some reagents which may be alkaline or acidic. The geopolymerization process involves the reaction between alumina-silicate (Al-Si) materials known as precursors and reagents producing a three-dimensional polymeric network. In this manuscript, a detailed classification along with various oxide contents present in the precursors globally used for geopolymer concrete (GPC) production is extracted. As precursors used in the process of geopolymerization involve a wide range of variations in their physio-chemical features, it becomes difficult to control the GPC properties without going into a micro-level understanding of the precursor characteristics affecting the geopolymerization mechanism. A comprehensive study is conducted on the influence of these physiochemical precursor characteristics on the geopolymerization process and GPC property development. Finally, a critical observation is drawn to design a suitable precursor, along with possible methods employed to achieve desired GPC property development.","PeriodicalId":18113,"journal":{"name":"Magazine of Concrete Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141826542","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Yield line-based design of fibre reinforced concrete: assessment of suitability of material models 基于屈服线的纤维增强混凝土设计：材料模型适用性评估

IF 1.8 4区工程技术

Magazine of Concrete Research Pub Date : 2024-07-17 DOI: 10.1680/jmacr.24.00096

Ajeesh Koorikkattil, S. K. Nayar, Veena Venudharan

{"title":"Yield line-based design of fibre reinforced concrete: assessment of suitability of material models","authors":"Ajeesh Koorikkattil, S. K. Nayar, Veena Venudharan","doi":"10.1680/jmacr.24.00096","DOIUrl":"https://doi.org/10.1680/jmacr.24.00096","url":null,"abstract":"The present research is intended to address the adequacy of flexural toughness-based material models such as equivalent and residual flexural strength, and the deflection limits at which these parameters are estimated for design of fibre reinforced concrete (FRC), for various applications such as slabs-on-grade/pavements. The work is an experimental study using FRC concrete mixes with individual and hybrid combinations of hooked-end steel (SF) and macro polypropylene fibres (PF). The experimental investigation consisted of toughness testing unnotched and notched prisms and square slabs, prepared with a typical grade of concrete used for FRC pavement applications. To validate the material models, a comparison was made between the theoretical moment/load calculated based on material flexural toughness parameters and the actual moment obtained from slabs using actual yield line formed during testing. From the study it is observed that overall, both equivalent (from unnotched prism test) and residual (from notched prism test) flexural strength, are suitable for designing FRC slabs, however the equivalent strength parameter shows better correlation to the slab response. The results also indicate that the hybrid mixes of PF and SF, with a higher volume fraction of 0.6% Vf, shows a marginal increase in flexural performance, in comparison to the mixes with lower volume fraction but no or minimal synergy due to hybridisation.","PeriodicalId":18113,"journal":{"name":"Magazine of Concrete Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141830077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Durability properties of slag-waste glass binary geopolymer 矿渣-废玻璃二元土工聚合物的耐久性能

IF 1.8 4区工程技术

Magazine of Concrete Research Pub Date : 2024-07-16 DOI: 10.1680/jmacr.24.00086

Datla Neeraj Varma, Suresh Prasad Singh

引用次数: 0

Early strength and durability of tannery sludge metakaolin based geopolymer concrete pavement repair material 基于制革污泥偏高岭土的土工聚合物混凝土路面修补材料的早期强度和耐久性

IF 1.8 4区工程技术

Magazine of Concrete Research Pub Date : 2024-07-12 DOI: 10.1680/jmacr.23.00289

Mantong Jin, Ganghong Yang, Zhuohui Wang, Peisen Zhao, Xinrun Zheng, Zhiyan Pan, Jiangfan Wu

{"title":"Early strength and durability of tannery sludge metakaolin based geopolymer concrete pavement repair material","authors":"Mantong Jin, Ganghong Yang, Zhuohui Wang, Peisen Zhao, Xinrun Zheng, Zhiyan Pan, Jiangfan Wu","doi":"10.1680/jmacr.23.00289","DOIUrl":"https://doi.org/10.1680/jmacr.23.00289","url":null,"abstract":"In this study, approaches to synthesizing rapid tannery sludge/metakaolin geopolymer repair materials were explored to investigate tannery sludge treatment and utilization. The setting time and 1-d compressive strength were taken as indicators for evaluating the performance of the geopolymer as a repair material. The effects of the Si/Al ratio, Na/Si ratio, water/cement ratio, and tannery sludge content were determined, and the durability of the geopolymer was also studied. The optimum formula met the requirements of a pavement repair material when the Si/Al ratio, Na/Si ratio, water/cement ratio, and tannery sludge content were 2.58, 0.33, 0.67, and 10%, respectively. The final setting times of this formula were 102 min. The 1-d compressive strength was 21.0 MPa, and the chromium leaching concentration was 7.52 mg·L−1. Additionally, the geopolymer exhibited good resistance to high temperatures and acid rain, and freeze-thaw processes. Therefore, a geopolymer repair material that exhibited high strength in the early stage and stable performance in the later stages was synthesized. XRD, FT-IR, MIP, and SEM were also conducted for micro-analysis, and it was found that the decrease in geopolymer gelation, and increases in the pore size and porosity resulted in a decrease in the properties of the repair materials.","PeriodicalId":18113,"journal":{"name":"Magazine of Concrete Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141654309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Mechanical processing of wet stored fly ash for use as a cement component in concrete 对用作混凝土水泥成分的湿储存粉煤灰进行机械加工

IF 1.8 4区工程技术

Magazine of Concrete Research Pub Date : 2024-07-09 DOI: 10.1680/jmacr.23.00303

M. J. McCarthy, T. Hope, L. Csetenyi

{"title":"Mechanical processing of wet stored fly ash for use as a cement component in concrete","authors":"M. J. McCarthy, T. Hope, L. Csetenyi","doi":"10.1680/jmacr.23.00303","DOIUrl":"https://doi.org/10.1680/jmacr.23.00303","url":null,"abstract":"Wet storage effects on fly ash, mean processing may be necessary to achieve physical properties required for use in concrete. This paper considers drying, de-agglomeration and milling of various wet stored fly ashes at laboratory and pilot/benchtop scales, towards meeting these. In the laboratory, different batch quantities and milling times with as received/pre-screened materials were examined using a ball mill. Greater particle size reductions were obtained with increased milling time but at gradually reducing rates. Pre-screening and batch quantity had relatively minor effects on particle size reductions, with little difference found between these materials and dry stored fly ash. Extended milling time resulted in: a darkening of colour; slight increases in loss-on-ignition, the main oxides content, and crystalline components; reductions in water requirement (to a point); and greater reactivity. Similar effects were generally noted in concrete for the superplasticizing admixture dose to achieve a target slump and compressive (cube) strength. At pilot/benchtop scale, a dryer-pulverizer and jet mill were used, which gave general agreement with the behaviour noted in the laboratory, but with the effects tending to be less. Fineness levels in Standards were achievable, with subsequent performance appearing to depend on the milling process used.","PeriodicalId":18113,"journal":{"name":"Magazine of Concrete Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141835885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0