"SP-178: Sixth CANMET/ACI/JCI Conference: FLy Ash, Silica Fume, Slag & Natural Pozzolans in Concrete"最新文献

Role of Pozzolanic and Cementious Material in Sustainable Development of the Concrete Industry 火山灰和胶凝材料在混凝土工业可持续发展中的作用

"SP-178: Sixth CANMET/ACI/JCI Conference: FLy Ash, Silica Fume, Slag & Natural Pozzolans in Concrete" Pub Date : 1998-06-01 DOI: 10.14359/5969

P. K. Mehta

引用次数: 98

Immobilization of Wastes by Metakaolin-Blended Cements 偏高岭土混合水泥对废弃物的固定化研究

"SP-178: Sixth CANMET/ACI/JCI Conference: FLy Ash, Silica Fume, Slag & Natural Pozzolans in Concrete" Pub Date : 1998-06-01 DOI: 10.14359/6019

J. Pera, E. Bonnin, M. Chabannet

引用次数: 5

High Strength Natural Lightweight Aggregate Concrete with Silica Fume 高强度天然轻骨料混凝土与硅粉

"SP-178: Sixth CANMET/ACI/JCI Conference: FLy Ash, Silica Fume, Slag & Natural Pozzolans in Concrete" Pub Date : 1998-06-01 DOI: 10.14359/6006

A. Yeğinobali, K. Sobolev, S. Soboleva, M. Tokyay

{"title":"High Strength Natural Lightweight Aggregate Concrete with Silica Fume","authors":"A. Yeğinobali, K. Sobolev, S. Soboleva, M. Tokyay","doi":"10.14359/6006","DOIUrl":"https://doi.org/10.14359/6006","url":null,"abstract":"High strength lightweight aggregate concretes are usually produced using special artificial aggregates together with mineral and chemical admixtures. Using natural lightweight aggregates instead of processed artificial aggregates can significantly reduce the cost of such concretes. Turkey has rich reserves of volcanic tuff and pumice stones. In Turkish standards highest strength classes for lightweight tuff and pumice concretes are 30 and 16 MPa, respectively. In this research, selected samples of these lightweight rocks were used to produce high strength lightweight aggregate concretes. The binding medium was made of portland cement, silica fume and superplasticizing admixture. For each concrete mixture properties such as workability, unit weight, compressive strength at various ages, as well as splitting tensile strength, modulus of elasticity and thermal conductivity values were determined to find the optimum quantities of materials to be used. Tests show that it is possible to produce a natural lightweight aggregate concrete with a 28-day compressive strength of 55 MPa, a dry unit weight in the range of 1700-2100 kg/m cubed and a coefficient of thermal conductivity value of about 0.55 W/m square K. Mathematical equations based on experimental results were obtained by regression analyses. The equations are useful for optimizing concrete mixtures for specified unit weight and compressive strength.","PeriodicalId":425482,"journal":{"name":"\"SP-178: Sixth CANMET/ACI/JCI Conference: FLy Ash, Silica Fume, Slag & Natural Pozzolans in Concrete\"","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129701407","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: 21

Influence of Storage Conditions and Concrete Composition on the Effectiveness of Different Silica Fumes Against ASR 贮存条件和混凝土成分对不同硅烟抗ASR效果的影响

"SP-178: Sixth CANMET/ACI/JCI Conference: FLy Ash, Silica Fume, Slag & Natural Pozzolans in Concrete" Pub Date : 1998-06-01 DOI: 10.14359/6027

M. Bérubé, J. Duchesne, J. Frenette

{"title":"Influence of Storage Conditions and Concrete Composition on the Effectiveness of Different Silica Fumes Against ASR","authors":"M. Bérubé, J. Duchesne, J. Frenette","doi":"10.14359/6027","DOIUrl":"https://doi.org/10.14359/6027","url":null,"abstract":"Cement paste samples incorporating various amounts of silica fume were made and stored in humid air at 23 degrees C and 38 degrees C. Their pore solution was expressed under high pressure at different times, then analyzed for its alkali content. The storage temperature did not significantly affect the alkal concentration in the short term (0-28 days), where most reaction products (hydrates) are formed. However, all control and blended pastes stored at 38 degrees C recycled very significant amounts of alkali in the pore solution between 28 days and 1.5 years, while not those stored at 23 degrees C. Consequently, the long-term effectiveness of silica fume against alkali-silica reaction (ASR) should be better than expected from a number of recent experimental studies all involving concrete expansion tests conducted at 38 degrees C, for field concretes exposed at an average lower temperature, e.g. in many regions of the world. This would explain at the same time why satisfactory field performance is reported in Iceland, for instance, while the only one case reported until now relating to poor field performance of silica fume against ASR took place under the hot South African climate. Results from concrete prism expansion tests also indicated that ASR expansion can develop in high performance concrete, even with moderately reactive aggregates. Other expansion results confirmed that the higher the degree of reactivity of the particular reactive aggregate to counteract, the alkali content in the silica fume, the alkali content in the portland cement used, and the cement dosage, in other words the higher the total concrete alkali content, the higher is the amount of silica fume required to counteract ASR expansion. The study also indicated that pelletizing the silica fume before mixing with the clinker at the grinding stage did not reduce its effectiveness against ASR, provided the grinding process is effective in dispersing the silica fume.","PeriodicalId":425482,"journal":{"name":"\"SP-178: Sixth CANMET/ACI/JCI Conference: FLy Ash, Silica Fume, Slag & Natural Pozzolans in Concrete\"","volume":"134 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128544396","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: 5

Slump Loss: A Single Rule for Ordinary Concrete 坍落度损失:普通混凝土的单一规则

"SP-178: Sixth CANMET/ACI/JCI Conference: FLy Ash, Silica Fume, Slag & Natural Pozzolans in Concrete" Pub Date : 1998-06-01 DOI: 10.14359/5991

B. Pollet, R. Lavaud, J. Baron

引用次数: 0

Effect and Mechanism of Natural Zeolite on Suppressing ASR in Concrete 天然沸石抑制混凝土ASR的效果及机理

"SP-178: Sixth CANMET/ACI/JCI Conference: FLy Ash, Silica Fume, Slag & Natural Pozzolans in Concrete" Pub Date : 1998-06-01 DOI: 10.14359/6009

N. Feng, H. Jia, T. Hao

引用次数: 0

Limestone Modified Cement for High-Performance Concretes 高性能混凝土用石灰石改性水泥

"SP-178: Sixth CANMET/ACI/JCI Conference: FLy Ash, Silica Fume, Slag & Natural Pozzolans in Concrete" Pub Date : 1998-06-01 DOI: 10.14359/6024

D. Montgomery, B. K. Van, I. Hinczak, K. Turner

引用次数: 4

The Use of Classified Fly Ash to Produce High Performance Concrete 分类粉煤灰在高性能混凝土中的应用

"SP-178: Sixth CANMET/ACI/JCI Conference: FLy Ash, Silica Fume, Slag & Natural Pozzolans in Concrete" Pub Date : 1998-06-01 DOI: 10.14359/5970

K. Hassan, J. Cabrera

{"title":"The Use of Classified Fly Ash to Produce High Performance Concrete","authors":"K. Hassan, J. Cabrera","doi":"10.14359/5970","DOIUrl":"https://doi.org/10.14359/5970","url":null,"abstract":"Waste materials may be upgraded to specification standards and occasionally to premium materials for use in the preparation of composites or for use on their own. The treatment for upgrading is a matter of cost and of the potential environmental problems that the treatment can create. The investigation presented in this paper shows an example of the improvements of fly ash properties achieved by a simple physical process, that is, air cyclone separation. This process gives a very fine ash with adequate pozzolanic activity and is suitable for producing high performance concrete with excellent durability, particularly when exposed to aggressive environments. This paper presents data on the properties of the fine fly ash, including lime reactivity, composition, size distribution and shape. The investigation was carried out using two fly ashes obtained by the process of air separation, using a prototype small air cyclone separator and an air mini-splitter. The properties of these ashes were compared to the properties of the original raw ash and with the properties of a fly ash processed industrially by the conventional mechanical separation process, which produces a fly ash conforming to the appropriate British specifications for use in the production of structural concrete. In this test programme, high performance concrete made with 0.3 fly ash and 0.7 ordinary Portland cement (by weight) as binder was assessed by measuring strength, porosity, and permeability. These properties were used to evaluate the performance of concrete and potential long term durability.","PeriodicalId":425482,"journal":{"name":"\"SP-178: Sixth CANMET/ACI/JCI Conference: FLy Ash, Silica Fume, Slag & Natural Pozzolans in Concrete\"","volume":"64 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125070398","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: 5

Suitability of Fumed Lead Blast-Furnace Slag as a Mineral Admixture for Concrete 铅渣作为混凝土掺合料的适宜性

"SP-178: Sixth CANMET/ACI/JCI Conference: FLy Ash, Silica Fume, Slag & Natural Pozzolans in Concrete" Pub Date : 1998-06-01 DOI: 10.14359/6022

D. L. Thomas, Mda Thomas, J. Ryell

{"title":"Suitability of Fumed Lead Blast-Furnace Slag as a Mineral Admixture for Concrete","authors":"D. L. Thomas, Mda Thomas, J. Ryell","doi":"10.14359/6022","DOIUrl":"https://doi.org/10.14359/6022","url":null,"abstract":"This paper reports the findings from a laboratory evaluation of a metallurgical slag as a pozzolanic admixture for concrete. Lead blast-furnace slag is fumed in a batch process to remove base metal values after which the molten barren slag is water-quenched to produce a glassy, granular product. Chemical analysis shows the principal components of the slag to be silica, iron and calcium with lesser amounts of alumina, zinc and copper. Semi-quantitative x-ray diffraction analysis revealed the slag to be largely amorphous (>60% glass), the crystalline phases being apparently confined to mineral varieties of iron oxide and cuprite. The slag was ground to produce three samples with different Blaine fineness values and tested for compliance with the Canadian Standard for Supplementary Cementing Materials (CSA A23.5). The effect of the slag on a range of fresh and hardened concrete properties was then determined. Concrete mixtures were also cast using commercially available fly ash from a sub-bituminous coal source in Western Canada for comparison. The slag meets all the requirements of Type N, F and C materials and failed only the 45-microns sieve retention maximum of Type G. The results of concrete tests (setting time, compressive strength development, drying shrinkage and rapid chloride permeability) are very encouraging. The incorporation of slag slightly retarded the early strength gain of concrete, but after 28 days the strength of the slag concrete exceeded that of the control concretes of the same W/CM, regardless of the level of slag (in the range 20 to 40%). The strength of slag concrete was higher than that of concrete containing the same level of fly ash and the same W/CM at all ages. The coulomb ratings of the concretes containing slag were lower than those obtained on equivalent control concretes but were higher than those of the fly ash concretes. The results from these preliminary tests indicate that the lead blast-furnace slag is suitable as a pozzolanic admixture for concrete.","PeriodicalId":425482,"journal":{"name":"\"SP-178: Sixth CANMET/ACI/JCI Conference: FLy Ash, Silica Fume, Slag & Natural Pozzolans in Concrete\"","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134223705","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: 2

Pozzolanic Properties of Metakaolin Obtained from Paper Sludge 造纸污泥中偏高岭土的火山灰性质

"SP-178: Sixth CANMET/ACI/JCI Conference: FLy Ash, Silica Fume, Slag & Natural Pozzolans in Concrete" Pub Date : 1998-06-01 DOI: 10.14359/6020

J. Pera, J. Ambroise

引用次数: 15

"SP-178: Sixth CANMET/ACI/JCI Conference: FLy Ash, Silica Fume, Slag &amp; Natural Pozzolans in Concrete"最新文献

"SP-178: Sixth CANMET/ACI/JCI Conference: FLy Ash, Silica Fume, Slag & Natural Pozzolans in Concrete"最新文献