RILEM Technical Letters最新文献_第8页

Testing properties governing the durability of lime-based repair mortars 石灰基修补砂浆耐久性试验

RILEM Technical Letters Pub Date : 2019-03-18 DOI: 10.21809/RILEMTECHLETT.2018.81

I. Papayianni, J. Hughes

{"title":"Testing properties governing the durability of lime-based repair mortars","authors":"I. Papayianni, J. Hughes","doi":"10.21809/RILEMTECHLETT.2018.81","DOIUrl":"https://doi.org/10.21809/RILEMTECHLETT.2018.81","url":null,"abstract":"Lime-based mortars (LM(s)) seem to be preferred in repairing historic structures. The long-term performance of repair LM(s) is closely related to durability issues concerning the old structure substrate, the new repair mortars and interface between the two aforementioned materials, which is also much influenced by the technique of mortars application. \u0000Durability is a multifunctional property affected by a number of parameters, including local environmental conditions. However, experience showed that some of the characteristics of materials play a dominant role in assessing the durability of repair LM(s) and have a direct impact on longevity of the repaired structure. \u0000This paper presents review of research/case studies papers and Master/PhD theses supervised by the members of RILEM TC 277 LHS. Through the review and evaluation of research and common practice concerning durability challenges, we anticipate to find answers to questions arising in assessing durability of repair LM(s), such as: \u0000 \u0000The most often encountered failures due to mortar durability inadequacy \u0000The mortar properties/characteristics that seem to be influential on durability \u0000The test methods used for testing the durability of LM(s) and comments related to their applicability and performance \u0000The importance of quality control and on site execution practices \u0000","PeriodicalId":36420,"journal":{"name":"RILEM Technical Letters","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48154419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 9

Instantaneous activation energy of alkali activated materials 碱活性物质的瞬时活化能

RILEM Technical Letters Pub Date : 2019-03-12 DOI: 10.21809/RILEMTECHLETT.2018.78

Shiju Joseph, S. Uppalapati, Ö. Cizer

引用次数: 6

Seismic behavior and assessment of masonry heritage structures. Needs in engineering judgement and education 砌体遗产结构的抗震性能与评价。需要工程判断和教育

RILEM Technical Letters Pub Date : 2019-03-07 DOI: 10.21809/RILEMTECHLETT.2018.76

P. Lourenço, G. Karanikoloudis

引用次数: 13

Plant based chemical admixtures – potentials and effects on the performance of cementitious materials 植物基化学外加剂——对胶结材料性能的潜力和影响

RILEM Technical Letters Pub Date : 2019-03-01 DOI: 10.21809/RILEMTECHLETT.2018.83

W. Schmidt, I. L. Tchetgnia Ngassam, K. Olonade, R. Mbugua, H. Kühne

引用次数: 10

Method for experimentally determining N-A-S-(H) solubility 实验测定N-A-S-(H)溶解度的方法

RILEM Technical Letters Pub Date : 2019-02-19 DOI: 10.21809/RILEMTECHLETT.2018.63

T. Williamson, Joonkyoung Han, L. Katz, G. Sant, M. Juenger

{"title":"Method for experimentally determining N-A-S-(H) solubility","authors":"T. Williamson, Joonkyoung Han, L. Katz, G. Sant, M. Juenger","doi":"10.21809/RILEMTECHLETT.2018.63","DOIUrl":"https://doi.org/10.21809/RILEMTECHLETT.2018.63","url":null,"abstract":"Inorganic polymer binders, also sometimes called geopolymers or alkali-activated cements, can serve as an alternative to ordinary portland cement (OPC) in concrete. The development of thermodynamic models to predict phase development and, ultimately, engineering properties, of inorganic polymer binders is an important step toward enabling their widespread use. However, such models require self-consistent solubility data of the primary phase in inorganic polymer binders, sodium aluminosilicate hydrate(s). To date, there is very little solubility information available for this phase. Here, a rigorous method for synthesizing sodium aluminosilicate hydrate(s) of controlled composition, and for measuring its solubility is presented. This approach allows complete stoichiometric control over the (initial) solution composition to elucidate directly the development of N-A-S-H composition as it relates to a given solution composition. A review of previous literature related to the solubility of other cementitious materials is presented, and the need for thermodynamic data is discussed. Finally, a sample calculation is presented for determining the solubility product (Ksp) of a laboratory synthesized sodium aluminosilicate hydrate.","PeriodicalId":36420,"journal":{"name":"RILEM Technical Letters","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45179865","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

The influence of asphalt ageing on induction healing effect on porous asphalt concrete 沥青老化对多孔沥青混凝土诱导愈合效果的影响

RILEM Technical Letters Pub Date : 2019-02-18 DOI: 10.21809/RILEMTECHLETT.2018.74

Shi Xu, Xueyan Liu, A. Tabaković, E. Schlangen

引用次数: 9

Extrusion of cement-based materials - an overview 水泥基材料的挤压——综述

RILEM Technical Letters Pub Date : 2019-02-13 DOI: 10.21809/RILEMTECHLETT.2018.75

A. Perrot, D. Rangeard, V. Nerella, V. Mechtcherine

引用次数: 57

Holistic modelling approach for special concrete: from fresh- to hardened-state 特殊混凝土的整体建模方法:从新鲜状态到硬化状态

RILEM Technical Letters Pub Date : 2019-01-18 DOI: 10.21809/RILEMTECHLETT.2018.67

S. Cavalaro, A. Blanco, R. Pieralisi

{"title":"Holistic modelling approach for special concrete: from fresh- to hardened-state","authors":"S. Cavalaro, A. Blanco, R. Pieralisi","doi":"10.21809/RILEMTECHLETT.2018.67","DOIUrl":"https://doi.org/10.21809/RILEMTECHLETT.2018.67","url":null,"abstract":"In the construction industry, the design of dimensions and material properties is generally separated from the design of material composition and of the production processes used. Such divide is enabled by robust construction materials (like concrete) little affected by production processes if minimum precautionary measures are in place. The same does not hold true for special concrete types; whose higher sensibility compels a shift towards more comprehensive approaches that assimilate the production process in a holistic design. The design driven by integrated numerical simulations encompassing from production to the long-term performance is already ordinary in the manufacturing of plastic and metallic parts. Nevertheless, it remains an alien to the construction industry. The objective of this paper is to review existing studies that might underpin this holistic design approach in construction and show some of its capabilities. Advanced modelling strategies available to simulate the behaviour from the fresh- to the hardened-state are discussed for the cases of pervious concrete and fibre reinforced concrete. This approach provides a deeper insight about the material behaviour and aids to a new level of numerical optimisation of their compositions and production processes, unlocking a potential transformation of the modus operandi of the construction industry.","PeriodicalId":36420,"journal":{"name":"RILEM Technical Letters","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42060011","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Detection of the critical chloride threshold of carbon steel rebar in synthetic concrete pore solutions. 碳素钢筋在合成混凝土孔隙溶液中氯离子临界阈值的检测。

RILEM Technical Letters Pub Date : 2019-01-16 DOI: 10.21809/RILEMTECHLETT.2018.70

I. Ogunsanya, C. Hansson

{"title":"Detection of the critical chloride threshold of carbon steel rebar in synthetic concrete pore solutions.","authors":"I. Ogunsanya, C. Hansson","doi":"10.21809/RILEMTECHLETT.2018.70","DOIUrl":"https://doi.org/10.21809/RILEMTECHLETT.2018.70","url":null,"abstract":"Knowledge of the critical chloride content in concrete required to initiate corrosion of reinforcing steel is economically beneficial for the assessment and maintenance of existing structures. Also, many building codes now specify a service life of 75 – 100 years for highway bridges and the critical chloride content is an essential input parameter in the models used in design of structures. There have been numerous studies aimed at determining this parameter but there is no consensus because of the many factors influencing the corrosion. The current standard methods, e.g. ASTM G109, require many weeks or months of testing and are not appropriate for testing large numbers of specimens in different conditions. \u0000This project has demonstrated that a fairly rapid potentiodynamic polarization technique can be applied to carbon steel reinforcing bars in synthetic concrete pore solution to determine the critical value, as illustrated in the figure. The importance of selecting the appropriate synthetic concrete pore solution for this application is demonstrated by the different critical values obtained for different solutions. \u0000The success of this test will allow the influence of different reinforcing alloys and different cementitious material mixes on the critical chloride content to be determined in a reasonable period of time. \u0000 ","PeriodicalId":36420,"journal":{"name":"RILEM Technical Letters","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42998948","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 9

Utilization of volcanic ejecta as a high-performance supplementary cementitious material by gravity classification and pulverization 火山喷出物作为高性能辅助胶凝材料的重力分级和粉碎利用

RILEM Technical Letters Pub Date : 2018-12-31 DOI: 10.21809/RILEMTECHLETT.2018.66

A. Tomoyose, T. Noguchi, K. Sodeyama, K. Higashi

{"title":"Utilization of volcanic ejecta as a high-performance supplementary cementitious material by gravity classification and pulverization","authors":"A. Tomoyose, T. Noguchi, K. Sodeyama, K. Higashi","doi":"10.21809/RILEMTECHLETT.2018.66","DOIUrl":"https://doi.org/10.21809/RILEMTECHLETT.2018.66","url":null,"abstract":"The reaction of natural pozzolans is caused by volcanic glass composed of amorphous silicate; however, volcanic ejecta also contains crystal mineral, pumice, and sometimes weathered clay fraction in their natural conditions. By focusing on the differences of physical properties between these components, high-purity volcanic glass powder (VGP) was manufactured by dry gravity classification and pulverization. This paper reports the results of investigations to utilize pyroclastic flow deposits as a supplementary cementitious material (SCM). \u0000Through this method, the glass content of VGP increased to 88% with a mean particle size of 1 μm, when that of the raw material is about 60%. Chemical analysis indicated that VGP is principally composed of silica (about 72%) and alumina (about 13%). \u0000The performance of VGP as a SCM was evaluated by conducting tests on concrete mixtures, replacing 0% to 30% by weight of portland cement by VGP with a 20% to 60% water to cement ratio. VGP concrete showed better results of 7-and 28-day compressive strength compared to control concrete in all experiments. In particular, VGP demonstrated better flowability and strength development in concrete with a low water-binder ratio in comparison to silica fume.","PeriodicalId":36420,"journal":{"name":"RILEM Technical Letters","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44966114","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4