Kinds of concrete shrinkages, their importance and prevention methods

IF 0.5 4区 工程技术 Q4 CONSTRUCTION & BUILDING TECHNOLOGY Cement Wapno Beton Pub Date : 2021-01-01 DOI:10.32047/cwb.2021.26.2.5
W. Kurdowski
{"title":"Kinds of concrete shrinkages, their importance and prevention methods","authors":"W. Kurdowski","doi":"10.32047/cwb.2021.26.2.5","DOIUrl":null,"url":null,"abstract":"The basis for the geopolymers production was drawn up by prof. Kühl, well known to present day from the introduction of the modulus of clinker lime saturation: This Kühl’s formula was lined on the assumption that the best clinker should be composed of C3S, C3A and C2F and the mass ratio of CaO in respect to other components is equal adequately: 2.8, 1.65 and 0.70. The analyses of the equilibrium condition in the four components system led Kühl to the so-called lime criterion, equal to the permissible maximal lime content in clinker, in the conditions far from the equilibrium: One of the unfavourable properties of concrete is shrinkage which is linked with the volume changes of cement paste. We distinguish the following kinds of shrinkage: – “chemical” shrinkage called also the contraction or Le Chatelier shrinkage, – plastic shrinkage, – autogenic shrinkage or spontaneous, sometimes called auto drying, – drying shrinkage. There are several methods to eliminate concrete shrinkage. The ettringite crystallization is one of the inorganic compounds methods and is based on Klein’s complex addition to cement. This complex is causing the rapid ettringite formation and the shrinkage is diminished. There are also organic admixtures which action is the reduction of the water surface tension. There are surface-active additions that are reducing this tension, in capillaries. The organic admixtures which are diminishing the shrinkage are based on neopentyl glycol or similar chemical compounds. In the study, the shrinkage-reducing admixture BASF Master Life SRA 815 alone and with CaO addition were examined. It was shown that CaO addition is giving very low diminishing of cement shrinkage, contrary to the fluid admixture Master Life SRA 815 which has a high diminishing influence on cement shrinkage. However, the simultaneous addition of CaO is increasing the diminishing influence of this fluid admixture. The addition of Klein’s complex does not influence of shrinkage but its simultaneous addition with Master Life SRA 815 gives higher shrinkage diminishing.","PeriodicalId":55632,"journal":{"name":"Cement Wapno Beton","volume":null,"pages":null},"PeriodicalIF":0.5000,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"2","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Cement Wapno Beton","FirstCategoryId":"5","ListUrlMain":"https://doi.org/10.32047/cwb.2021.26.2.5","RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"CONSTRUCTION & BUILDING TECHNOLOGY","Score":null,"Total":0}
引用次数: 2

Abstract

The basis for the geopolymers production was drawn up by prof. Kühl, well known to present day from the introduction of the modulus of clinker lime saturation: This Kühl’s formula was lined on the assumption that the best clinker should be composed of C3S, C3A and C2F and the mass ratio of CaO in respect to other components is equal adequately: 2.8, 1.65 and 0.70. The analyses of the equilibrium condition in the four components system led Kühl to the so-called lime criterion, equal to the permissible maximal lime content in clinker, in the conditions far from the equilibrium: One of the unfavourable properties of concrete is shrinkage which is linked with the volume changes of cement paste. We distinguish the following kinds of shrinkage: – “chemical” shrinkage called also the contraction or Le Chatelier shrinkage, – plastic shrinkage, – autogenic shrinkage or spontaneous, sometimes called auto drying, – drying shrinkage. There are several methods to eliminate concrete shrinkage. The ettringite crystallization is one of the inorganic compounds methods and is based on Klein’s complex addition to cement. This complex is causing the rapid ettringite formation and the shrinkage is diminished. There are also organic admixtures which action is the reduction of the water surface tension. There are surface-active additions that are reducing this tension, in capillaries. The organic admixtures which are diminishing the shrinkage are based on neopentyl glycol or similar chemical compounds. In the study, the shrinkage-reducing admixture BASF Master Life SRA 815 alone and with CaO addition were examined. It was shown that CaO addition is giving very low diminishing of cement shrinkage, contrary to the fluid admixture Master Life SRA 815 which has a high diminishing influence on cement shrinkage. However, the simultaneous addition of CaO is increasing the diminishing influence of this fluid admixture. The addition of Klein’s complex does not influence of shrinkage but its simultaneous addition with Master Life SRA 815 gives higher shrinkage diminishing.
查看原文
分享 分享
微信好友 朋友圈 QQ好友 复制链接
本刊更多论文
混凝土收缩的种类、重要性及预防方法
地聚合物生产的基础是由k hl教授提出的,他从熟料石灰饱和模量的引入到今天都很出名:k hl的公式是基于最好的熟料应该由C3S、C3A和C2F组成,CaO相对于其他组分的质量比是充分相等的:2.8、1.65和0.70。通过对四组分体系平衡条件的分析,k hl得出了所谓的石灰准则,即熟料中允许的最大石灰含量,在远离平衡的条件下:混凝土的不利性能之一是收缩,这与水泥浆体的体积变化有关。我们区分以下几种收缩:-“化学”收缩也称为收缩或勒夏特列收缩,-塑性收缩,-自生收缩或自发,有时称为自动干燥,-干燥收缩。消除混凝土收缩的方法有几种。钙矾石结晶法是一种无机化合物方法,其基础是水泥中克莱因络合物的加入。这种复合体导致钙矾石快速形成,收缩减少。也有有机外加剂,其作用是降低水的表面张力。在毛细血管中,有表面活性添加剂可以降低这种张力。减少收缩的有机外加剂是基于新戊二醇或类似的化合物。研究了巴斯夫主寿命减水剂SRA 815单独和添加CaO的减水剂。结果表明,CaO的加入对水泥收缩的抑制作用很小,而Master Life SRA 815对水泥收缩的抑制作用很大。然而,同时加入CaO会增加这种流体混合物的影响。克莱因配合物的加入对收缩率没有影响,但与主寿命SRA 815同时加入后,收缩率减小较大。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
求助全文
约1分钟内获得全文 去求助
来源期刊
Cement Wapno Beton
Cement Wapno Beton CONSTRUCTION & BUILDING TECHNOLOGY-MATERIALS SCIENCE, COMPOSITES
CiteScore
1.30
自引率
28.60%
发文量
0
审稿时长
>12 weeks
期刊介绍: The Publisher of the scientific bimonthly of international circulation, entitled "Cement-Wapno-Beton" ["Cement-Lime-Concrete"], is the Fundacja Cement, Wapno, Beton [Foundation Cement, Lime, Concrete]. The periodical is dedicated to the issues concerning mineral setting materials and concrete. It is concerned with the publication of academic and research works from the field of chemistry and technology of building setting materials and concrete
期刊最新文献
Investigation of calcite and huntite/hydromagnesite mineral in co-presence regarding flame retardant and mechanical properties of wood composites Durability self-compacting mortar under external chemical attacks based on composite binder Perspective of concrete with Portland composite cement CEM II/C-M (S-LL) Transport Properties of Internally Cured Self Compacting Concrete with Fly Ash Environmental Assessment of Construction Products – Challenges, Priorities, and Needs from Producers’ Perspective. A Review
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
现在去查看 取消
×
提示
确定
0
微信
客服QQ
Book学术公众号 扫码关注我们
反馈
×
意见反馈
请填写您的意见或建议
请填写您的手机或邮箱
已复制链接
已复制链接
快去分享给好友吧!
我知道了
×
扫码分享
扫码分享
Book学术官方微信
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术
文献互助 智能选刊 最新文献 互助须知 联系我们:info@booksci.cn
Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。
Copyright © 2023 Book学术 All rights reserved.
ghs 京公网安备 11010802042870号 京ICP备2023020795号-1