{"title":"Considerations for Handling of Mass Concrete: Control of Internal Restraint","authors":"A. M. Lawrence, M. Tia, M. Bergin","doi":"10.14359/51686403","DOIUrl":null,"url":null,"abstract":"This paper presents the findings of an investigation in which the finite element method was used to assess the effects of various construction procedures on the cracking performance of a hydrating massive concrete element. A 1.07 x 1.07 x 1.07 m (3.5 x 3.5 x 3.5 ft) concrete block is modeled using the DIANA finite element analysis software and the inputs for the mechanical and thermal proper¬ties of early-age concrete based on values obtained experimentally from a concrete mixture used in the construction of mass concrete in Florida. It was shown that, for insulation with a given thermal resistance, as the size of concrete placement increases, greater reduction of the temperature differential can be achieved by simply using additional layers of polystyrene foam or insulating blankets. The study also found that the attained tensile strength of concrete should be considered before the formwork and accompanying insulation used in mass concrete applications are removed to ensure that the stresses that result from the sudden cooling of the concrete surface are sufficiently lower, thereby reducing the likelihood of thermal cracking.","PeriodicalId":18281,"journal":{"name":"Materials","volume":null,"pages":null},"PeriodicalIF":3.1000,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"6","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Materials","FirstCategoryId":"88","ListUrlMain":"https://doi.org/10.14359/51686403","RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
引用次数: 6
Abstract
This paper presents the findings of an investigation in which the finite element method was used to assess the effects of various construction procedures on the cracking performance of a hydrating massive concrete element. A 1.07 x 1.07 x 1.07 m (3.5 x 3.5 x 3.5 ft) concrete block is modeled using the DIANA finite element analysis software and the inputs for the mechanical and thermal proper¬ties of early-age concrete based on values obtained experimentally from a concrete mixture used in the construction of mass concrete in Florida. It was shown that, for insulation with a given thermal resistance, as the size of concrete placement increases, greater reduction of the temperature differential can be achieved by simply using additional layers of polystyrene foam or insulating blankets. The study also found that the attained tensile strength of concrete should be considered before the formwork and accompanying insulation used in mass concrete applications are removed to ensure that the stresses that result from the sudden cooling of the concrete surface are sufficiently lower, thereby reducing the likelihood of thermal cracking.
本文介绍了一项调查的结果,其中有限元法用于评估各种施工程序对水化大体积混凝土元件开裂性能的影响。一个1.07 x 1.07 x 1.07 m (3.5 x 3.5 x 3.5英尺)的混凝土块使用DIANA有限元分析软件和早期混凝土的机械和热特性输入进行建模,这些输入基于从佛罗里达州大体积混凝土施工中使用的混凝土混合物中获得的实验值。研究表明,对于具有给定热阻的隔热材料,随着混凝土浇筑尺寸的增加,通过简单地使用额外的聚苯乙烯泡沫层或隔热毯,可以实现更大程度的温差降低。研究还发现,在拆除大体积混凝土应用中使用的模板和伴随的绝缘材料之前,应考虑混凝土的抗拉强度,以确保混凝土表面突然冷却产生的应力足够低,从而减少热裂的可能性。
期刊介绍:
Materials (ISSN 1996-1944) is an open access journal of related scientific research and technology development. It publishes reviews, regular research papers (articles) and short communications. Our aim is to encourage scientists to publish their experimental and theoretical results in as much detail as possible. Therefore, there is no restriction on the length of the papers. The full experimental details must be provided so that the results can be reproduced. Materials provides a forum for publishing papers which advance the in-depth understanding of the relationship between the structure, the properties or the functions of all kinds of materials. Chemical syntheses, chemical structures and mechanical, chemical, electronic, magnetic and optical properties and various applications will be considered.