Magazine of Concrete Research最新文献_第10页

Characterization and standardization of different-origin end-of-life building materials toward assessment of circularity performance 面向循环性能评估的不同来源的报废建筑材料的特性和标准化

4区工程技术

Magazine of Concrete Research Pub Date : 2023-09-28 DOI: 10.1680/jmacr.23.00011

Emircan Ozcelikci, Gurkan Yildirim, Hocine Siad, Mohamed Lachemi, Mustafa Sahmaran

{"title":"Characterization and standardization of different-origin end-of-life building materials toward assessment of circularity performance","authors":"Emircan Ozcelikci, Gurkan Yildirim, Hocine Siad, Mohamed Lachemi, Mustafa Sahmaran","doi":"10.1680/jmacr.23.00011","DOIUrl":"https://doi.org/10.1680/jmacr.23.00011","url":null,"abstract":"Construction and demolition waste (CDW) management and recycling practices are crucial for transitioning to a circular economy. The focus of this study was on the detailed characterisation of different CDWs (hollow brick (HB), red clay brick (RCB), roof tile (RT), concrete and glass) collected from seven different demolition sites in Turkey. The CDWs were characterised based on particle size distribution, chemical composition and crystalline nature. Pozzolanic activity was evaluated through compressive strength measurements of cement mortars made with 20% cement replacement by CDWs at 7, 28 and 90 days. The results showed that the clayey CDWs exhibited similar physical/chemical properties and crystalline structures. The compositions of the waste concretes varied significantly based on their original materials. All the CDWs satisfied the minimum strength activity index (SAI) for supplementary cementitious materials, with pozzolanic activity influenced by the fineness and silica + alumina contents. The average SAIs for the HB, RCB, RT, concrete and glass were, respectively, 84.5%, 86.3%, 83.4%, 80.7% and 75.8%. Clayey CDWs contributed to mechanical strength development, while the contribution of concretes was related to the hydration of unreacted cementitious particles. Glass exhibited the weakest pozzolanic activity due to its coarser particle size. Overall, the CDWs demonstrated suitable properties for use as supplementary cementitious materials in Portland cement based systems.","PeriodicalId":18113,"journal":{"name":"Magazine of Concrete Research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135343010","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

Alkali activation of fly ash in self-consolidating concrete at low molar concentration 低摩尔浓度自密实混凝土中粉煤灰的碱活化

IF 2.7 4区工程技术

Magazine of Concrete Research Pub Date : 2023-09-05 DOI: 10.1680/jmacr.22.00342

Muthu Kumar Palanisamy, Arun Murugesan, Abdul Aleem Mohamed Ismail, Deepasree Srinivasan

{"title":"Alkali activation of fly ash in self-consolidating concrete at low molar concentration","authors":"Muthu Kumar Palanisamy, Arun Murugesan, Abdul Aleem Mohamed Ismail, Deepasree Srinivasan","doi":"10.1680/jmacr.22.00342","DOIUrl":"https://doi.org/10.1680/jmacr.22.00342","url":null,"abstract":"As a means of minimizing the negative effects on the environment, the use of industrial byproducts in the building industry is becoming more popular. In recent trends alkali activation of precursor's booms in the market since activation of precursors improves the binding strength and durability as well as reduce the carbon footprint from cementing industry. Although, one such risk factor in alkali activation is the molar concentration. Increase in molar concentration of sodium hydroxide/ sodium silicate, the release of volatile substance from those acids would be more harmful to the environment. In this concern, the present study works on activating the precursor at low molar concentration thereby equalizing the performance through dosage of super plasticizers. In this direction, fly-ash was activated at 5M (NaOH) and replaced to cement at varying percentage in the range of 0 to 30% by weight. The performance of SCC was evaluated through fresh & hardened characteristics, and microstructural analysis. Evaluating the blended mixtures of SCC, AFA at 5M (NaOH), 0.89% of super plasticizers and 15% of replacement sounds to be better performance than compared to control SCC. The outcome of the present study will provide platform in activating a precursor at low molar concentration through the influence of super plasticizers.","PeriodicalId":18113,"journal":{"name":"Magazine of Concrete Research","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2023-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49203479","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 high temperature on the compression and bending properties of AASCM 高温对AASCM压缩和弯曲性能的影响

IF 2.7 4区工程技术

Magazine of Concrete Research Pub Date : 2023-09-05 DOI: 10.1680/jmacr.23.00029

Xueyuan Lv, Hao Cheng, Pang Chen, Yonggan Li, Zhiyong Wang

{"title":"Influence of high temperature on the compression and bending properties of AASCM","authors":"Xueyuan Lv, Hao Cheng, Pang Chen, Yonggan Li, Zhiyong Wang","doi":"10.1680/jmacr.23.00029","DOIUrl":"https://doi.org/10.1680/jmacr.23.00029","url":null,"abstract":"Alkali-activated slag cementitious materials (AASCM) with manufactured sand can effectively utilise industrial waste slag and reduce river sand consumption. Steel fibres can effectively improve the mechanical properties of AASCM. Therefore, this study investigated the influence of steel fibre and aggregate type on the compression and bending properties of AASCM after high-temperature treatment. The results showed that the mass loss rate, compressive strength, and flexural strength loss rate of AASCM with manufactured sand were higher than those with natural river sand at different temperatures. Steel fibres can increase the mass loss rate of AASCM; however, the influence of the steel fibre content on the mass loss of AASCM was not apparent. When the temperature was lower than 600°C, the compressive and flexural strength of AASCM effectively was increased by steel fibre, while for temperatures higher than 800°C, the mechanical properties of AASCM did not improved owing to the oxidation failure of steel fibre. Microstructure analysis showed that the number of microcracks in the AASCM increased owing to the high silicon content of the manufactured sand, and the bond property between the steel fibres and cementitious materials decreased with an increase in temperature.","PeriodicalId":18113,"journal":{"name":"Magazine of Concrete Research","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2023-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41413165","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: 1

Application of electro-injection method in improving cement mortar durability 电喷射法在提高水泥砂浆耐久性中的应用

IF 2.7 4区工程技术

Magazine of Concrete Research Pub Date : 2023-08-18 DOI: 10.1680/jmacr.22.00063

Hongyou Shan, Jinxia Xu, Yuanhai Jiang, Hongfei Liu, Gang Zheng, Guomin Cui

{"title":"Application of electro-injection method in improving cement mortar durability","authors":"Hongyou Shan, Jinxia Xu, Yuanhai Jiang, Hongfei Liu, Gang Zheng, Guomin Cui","doi":"10.1680/jmacr.22.00063","DOIUrl":"https://doi.org/10.1680/jmacr.22.00063","url":null,"abstract":"An electrochemical method for improving durability of cement mortar by injection of nanoparticle (Al2O3 coated SiO2) is presented. In this method, nanoparticles are injected into cement mortar pores under an external electrical field, refining pore structure of cement mortar. The efficiency of electro-injection nano-particle treatment with different applied electric fields was evaluated by monitoring the evolution of cement mortar resistivity. The improvement of cement mortar durability after electro-injection of nano-particle treatment was assessed by examining the resistance to water absorption, carbonation, sulfate resistance and chloride diffusion. The microstructure of cement mortar after the electro-injection treatment was analyzed using Scanning Electron Microscope (SEM), Mercury Intrusion Porosimetry (MIP), X-Ray Diffraction (XRD) and Differential Thermo-Gravimetric Analysis (DTG). The results show that improving cement mortar durability by the injection of nanoparticle under external electric field can be obtained. The efficiency of electro-injection nano-particle treatment increased with the increasing of applied electric field. The resistance to water absorption, carbonation, sulfate attack and chloride diffusion were significantly improved by using the electro-injection method. The improvement in cement mortar durability can be attributed to the filling effect of nanoparticles.","PeriodicalId":18113,"journal":{"name":"Magazine of Concrete Research","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2023-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46578670","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: 1

Prediction of fire spalling behaviour of fiber reinforced concrete 纤维混凝土火灾剥落行为的预测

IF 2.7 4区工程技术

Magazine of Concrete Research Pub Date : 2023-08-15 DOI: 10.1680/jmacr.23.00060

Jingtai Jiang, Ming Wu, M. Ye

{"title":"Prediction of fire spalling behaviour of fiber reinforced concrete","authors":"Jingtai Jiang, Ming Wu, M. Ye","doi":"10.1680/jmacr.23.00060","DOIUrl":"https://doi.org/10.1680/jmacr.23.00060","url":null,"abstract":"Fire spalling prediction of fiber reinforced concrete containing polypropylene (PP) fiber and steel fiber at elevated temperature is a challenging problem. The conventional methods such as FEM and DEM are difficult to deal with the problem as a result of complicate coupling mechanism of polypropylene (PP) fiber and steel fiber in concrete. To this end, two artificial neural network (ANN) models, one (ANN1) is on the basis of concrete mix study and the other one (ANN2) is based on compressive strength study, are introduced in current study to assess the resistance of concrete to explosive spalling. A number of 321 and 318 test data gathered from literature are utilized to train the two proposed ANN models. Twenty-four concrete mixes (96 groups), i.e., seven plain concrete (PC) mixes, four high performance concrete (HPC) mixes reinforced with PP fiber, three ultra-high-performance concrete (UHPC) with reinforced PP fiber and ten ultra-high-performance concrete (UHPC) mixes reinforced with PP and steel hybrid fiber are designed and tested to validate the accuracy of the two models. It demonstrates that ANN1 and ANN2 can achieve a predictive accuracy of 89.6% and 84.4% for the explosive spalling respectively, which indicates the feasibility of proposed ANN models for predicting explosive spalling threat of the hybrid fiber reinforced concrete.","PeriodicalId":18113,"journal":{"name":"Magazine of Concrete Research","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2023-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44160508","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

Comparison of fundamental properties and durability of mortar mixed with antibacterial functional materials 掺抗菌功能材料砂浆的基本性能和耐久性比较

IF 2.7 4区工程技术

Magazine of Concrete Research Pub Date : 2023-08-15 DOI: 10.1680/jmacr.23.00001

Il-Sun Kim, So-Yeong Choi, E. Yang

引用次数: 1

Effect of typical formworks and release agents on the aesthetical surface quality of concrete 典型模板及脱模剂对混凝土表面美观质量的影响

IF 2.7 4区工程技术

Magazine of Concrete Research Pub Date : 2023-08-15 DOI: 10.1680/jmacr.23.00063

Jiang Qian, Yu Cheng, Maixi Zhou

{"title":"Effect of typical formworks and release agents on the aesthetical surface quality of concrete","authors":"Jiang Qian, Yu Cheng, Maixi Zhou","doi":"10.1680/jmacr.23.00063","DOIUrl":"https://doi.org/10.1680/jmacr.23.00063","url":null,"abstract":"This work investigated the formwork surface characteristics and concrete surface quality. The results showed, release agent types and formwork materials have a great impact on the wettability of formwork/concrete interface, although all the formwork surfaces with/without release agents are hydrophilic. Remarkably inhomogeneous roughness characteristic is only announced with steel formwork. Plywood and steel formworks have almost the same roughness values, however roughness profile of plywood is sharper than it of steel. Mineral oil always correlates to larger surface voids and higher surface void ratio (SVR) values. Steel formwork increases SVR significantly compared to the other two formworks. When SVR <1‰ and small voids (<500μm) >50%, the concrete surface seems to be bughole-free. Rusty stains left by steel formwork aggravates concrete discoloration degree, especially when water-soluble release agents were applied. To improve concrete surface quality, plywood formwork is more favorable despite release agents and vegetable oil based emulsion is more suitable for plastic formwork. The surface area roughness of concretes is mainly determined by it of formworks. The typical micro-groove feature on formwork surface leaves no trace on the formed concrete surface which might be due to the dimension difference between micro-grooves and cement particles and the presence of release agents.","PeriodicalId":18113,"journal":{"name":"Magazine of Concrete Research","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2023-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49019446","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

Mesoscale modelling of CRTS II slab tracks subjected to thermal action and vehicle loads CRTS II板式轨道在热作用和车辆荷载作用下的中尺度建模

IF 2.7 4区工程技术

Magazine of Concrete Research Pub Date : 2023-08-14 DOI: 10.1680/jmacr.23.00083

H. Chen, Wen-Bin Li, Yu Jiang

{"title":"Mesoscale modelling of CRTS II slab tracks subjected to thermal action and vehicle loads","authors":"H. Chen, Wen-Bin Li, Yu Jiang","doi":"10.1680/jmacr.23.00083","DOIUrl":"https://doi.org/10.1680/jmacr.23.00083","url":null,"abstract":"The damage and deformation of the cast-in-situ concrete joint between the precast concrete track slabs of the China Railway Track System (CRTS) II is crucial to the safe operation of high-speed railways. To investigate the damage and deformation evolution of the joint concrete under thermal action caused by the natural meteorological environment and vehicle loads, this paper develops a two-dimensional coupled thermal-mechanical numerical model of the concrete joint at mesoscale, which analyzes the influence of three factors; i.e., concrete strength, joint concrete aggregate maximum diameter and vehicle speed. First, the meteorology and heat transfer theory are introduced to the thermal simulations. Then, nonlinear characteristic of the joint concrete is modelled by the two-phase composite material based on the ‘random aggregate algorithm’ and strain-based elastic damage theory at mesoscale. Cohesive zone model (CZM) is utilized to simulate the interfaces between precast slabs. Finally, the reliability of the proposed model is confirmed by the validation study using field measurements. From the results of the numerical example, the maximum aggregate diameter of the joint concrete significantly affects the damage evolution of the joint concrete, and concrete strength has slight effects on the joint uplifting.","PeriodicalId":18113,"journal":{"name":"Magazine of Concrete Research","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2023-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41549630","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

Numerical simulations of fresh concrete flow in the L-Box test using CFD L-Box试验中新混凝土流动的CFD数值模拟

IF 2.7 4区工程技术

Magazine of Concrete Research Pub Date : 2023-08-01 DOI: 10.1680/jmacr.23.00032

Raoudha Sassi, A. Jelidi, S. Montassar

引用次数: 0

State of the art review of bamboo reinforced concrete structural elements 竹筋混凝土结构构件的研究现状

IF 2.7 4区工程技术

Magazine of Concrete Research Pub Date : 2023-07-31 DOI: 10.1680/jmacr.23.00050

P. Himasree, C. Korde, R. West, N. Ganesan

引用次数: 1