Cement Wapno Beton最新文献_第8页

The effect of size and shape of aggregate on compressive strength and ductility of concrete 骨料尺寸和形状对混凝土抗压强度和延性的影响

IF 0.7 4区工程技术

Cement Wapno Beton Pub Date : 2021-01-01 DOI: 10.32047/cwb.2021.26.1.5

H. R. Darvishvand, S. A. H. S. Taghia, M. Ebrahimi

引用次数: 2

Foamed glass granulated-based self-compacting mortars: open-porosity effect on rheological and mechanical properties 泡沫玻璃颗粒基自密实砂浆:开孔率对流变学和力学性能的影响

IF 0.7 4区工程技术

Cement Wapno Beton Pub Date : 2021-01-01 DOI: 10.32047/cwb.2021.26.3.6

S. Lecheb, A. Chellil, K. Chahour, B. Safi

{"title":"Foamed glass granulated-based self-compacting mortars: open-porosity effect on rheological and mechanical properties","authors":"S. Lecheb, A. Chellil, K. Chahour, B. Safi","doi":"10.32047/cwb.2021.26.3.6","DOIUrl":"https://doi.org/10.32047/cwb.2021.26.3.6","url":null,"abstract":"The foamed glass is currently used in the manufacture of concretes as aggregate to produce lightweight concrete. The lightness of the concrete is assured by the important porosity of foamed glass granulates [GFG], however, they have a closed porosity with a smooth surface. In this respect, this study aims to use foam glass granulates with open-porosity, to produce lightweight self-compacting mortars. GFG were prepared from the glass powder – glass cullet and foaming agent – limestone, according to the current applied process for GFG – heat treatment at 850°C for 20 min. Then from GFG the sand fine aggregate – 0/5 mm was prepared by crushing and sieving. The self-compacting mortars were obtained using natural sand as fine aggregate and other mortars with granulated foam glass substituting sand at volume ratios: 30, 50 and 100 %. Rheological tests of fluidity and physical properties, i.e. density and porosity, by measuring absorption of water and mechanical tests were carried out on studied mortars. The interface of cementitious matrix/GFG granules study shows that open-porosity of GFG sand has favored adhesion to cement matrix, without causing the segregation of the mortar phases. Also, the decrease of the compressive strength for mortars exhibiting a specific lightness, was found. It should be noted that the latter property is very important in construction.","PeriodicalId":55632,"journal":{"name":"Cement Wapno Beton","volume":"83 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90249803","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

Material properties of the light mass bricks from an 800 year old Heritage site in India 来自印度800年历史遗址的轻质砖的材料特性

IF 0.7 4区工程技术

Cement Wapno Beton Pub Date : 2021-01-01 DOI: 10.32047/cwb.2021.26.2.4

N. K. Degloorkar, Ratish K. Pancharathi

{"title":"Material properties of the light mass bricks from an 800 year old Heritage site in India","authors":"N. K. Degloorkar, Ratish K. Pancharathi","doi":"10.32047/cwb.2021.26.2.4","DOIUrl":"https://doi.org/10.32047/cwb.2021.26.2.4","url":null,"abstract":"Restoration and preservation of Heritage Structures in any countryis a challenging task and sometimes requires urgent attention. Moreover, it is important for sustenance of culture and heritage of the society. But many times, it is very diffi cult to find matching materials used in the past and hence due to use of available cementitious materials there can be degeneration of existing material. In view of this, there is a need to characterize these ancient materials and develop alternate materials with almost similar characteristics. With this knowledge, an alternate material similar in mineral composition and physical properties need to be developed, which will not have compatibility issues during and after repair. In the present study, the material characterization of an ancient floating brick at an Indian Heritage site was examined using modern analytical techniques like SEM-EDS, XRD and FTIR. In addition, the physical properties like specific gravity, bulk density, voids ratio and porosity were also determined. From the analysis, it could be confirmed that the bricks were light in weight due to the pores content and could float in water due to the non-interconnected porosity. Also, the presence of quartz, alumina and hematite from SEM-EDS analysis confirmed that these bricks were made of firing the clay, at lower temperatures, to induce pores. This low temperature firing of clay was supported by FTIR analysis indicating the presence of Si-O bond that would have disappeared at higher temperature.","PeriodicalId":55632,"journal":{"name":"Cement Wapno Beton","volume":"9 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87057618","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

Effect of ASR expansion on mechanical properties of concrete ASR膨胀对混凝土力学性能的影响

IF 0.7 4区工程技术

Cement Wapno Beton Pub Date : 2021-01-01 DOI: 10.32047/cwb.2021.26.1.2

Alkan Hafçi, L. Turanli, F. Bektaş

引用次数: 1

Kinds of concrete shrinkages, their importance and prevention methods 混凝土收缩的种类、重要性及预防方法

IF 0.7 4区工程技术

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":"https://doi.org/10.32047/cwb.2021.26.2.5","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":"5 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89682134","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: 2

Mechanical properties of magnesium phosphate cement incorporating basalt fibers 含玄武岩纤维的磷酸镁水泥的力学性能

IF 0.7 4区工程技术

Cement Wapno Beton Pub Date : 2021-01-01 DOI: 10.32047/cwb.2021.26.3.5

A. Pehlivan

引用次数: 1

Mechanical and durability properties of sintered fly ash aggregate concrete 粉煤灰烧结骨料混凝土的力学性能和耐久性

IF 0.7 4区工程技术

Cement Wapno Beton Pub Date : 2021-01-01 DOI: 10.32047/cwb.2021.26.5.3

S. Siva Chandran, K. Chinnaraju

引用次数: 0

Experimental investigation on strength properties of concrete incorporating ground pond ash 掺地塘灰混凝土强度特性试验研究

IF 0.7 4区工程技术

Cement Wapno Beton Pub Date : 2021-01-01 DOI: 10.32047/cwb.2021.26.3.7

K. Yuvaraj, S. Ramesh

{"title":"Experimental investigation on strength properties of concrete incorporating ground pond ash","authors":"K. Yuvaraj, S. Ramesh","doi":"10.32047/cwb.2021.26.3.7","DOIUrl":"https://doi.org/10.32047/cwb.2021.26.3.7","url":null,"abstract":"In the present era, the consumption of electricity has increased rapidly with each passing year, due to the industrialization. Coal is a raw material for the production of electricity in the thermal power stations. Particularly, a large amount of unused ash is dumped in ponds, which are major problem concerning many developing countries. Further, dumping of ash in ponds causes environmental hazards effects such as soil, land and water pollution. Identifying a viable alternative to utilize pond ash becomes a necessity, to avoid these environmental hazards. In this research work, an attempt has been made to partially replace cement by the pond ash as a supplementary cementitious material [SCM] in concrete, which will considerably reduce the hazardous effects of pond ash, to the environment. The pond ash was ground to 45 μm and it was used to replace the cement in concrete by proportions of 5, 10, 15, 20 and 25% by mass. Test on compressive strength, split tensile strength and modulus of rupture were conducted on concrete mixes. The result indicate that the addition of 10% pond ash to concrete significantly increased the strength properties of the concrete at the age of 7, 28, 56 and 90 days.","PeriodicalId":55632,"journal":{"name":"Cement Wapno Beton","volume":"32 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87941521","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: 7

Contemporary challenges of science and technology – selected reflections 当代科学技术的挑战——精选思考

IF 0.7 4区工程技术

Cement Wapno Beton Pub Date : 2021-01-01 DOI: 10.32047/cwb.2021.26.5.5

K. Furtak

{"title":"Contemporary challenges of science and technology – selected reflections","authors":"K. Furtak","doi":"10.32047/cwb.2021.26.5.5","DOIUrl":"https://doi.org/10.32047/cwb.2021.26.5.5","url":null,"abstract":"Modern challenges of science and technology should not be considered in isolation from the past and changes that have taken place over the centuries. They have occurred in different ways in various periods of human history and in various spheres of human activity, including technology. The changes also concern construction and construction materials. All changes have been stimulated by, inter alia, science and they, in turn, have determined and stimulated the development of science. The soaring growth in science and technological development result in a rising social awareness of increasing and new issues both technological and social that must be addressed. At the present stage of civilisation evelopment, they cannot be solved separately. The environmental and energy impacts must also be included. Special attention was focused on construction materials and products, as well as technological aspects including the application of 3D printing technology in construction. They all belong to the development of civilisation in a broad sense. In construction, there is room for traditional materials and technologies and their new versions with the primacy, however, of new generation materials. The need to apply the achievements in disciplines other than construction has been emphasised.","PeriodicalId":55632,"journal":{"name":"Cement Wapno Beton","volume":"1 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79904934","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

Unground granulated slag as a substitute for natural aggregate during concrete production 在混凝土生产中，未磨碎的矿渣作为天然骨料的替代品

IF 0.7 4区工程技术

Cement Wapno Beton Pub Date : 2021-01-01 DOI: 10.32047/cwb.2021.26.3.3

Ru Wang, Ziyan Xi, Gaoyong Wang

{"title":"Unground granulated slag as a substitute for natural aggregate during concrete production","authors":"Ru Wang, Ziyan Xi, Gaoyong Wang","doi":"10.32047/cwb.2021.26.3.3","DOIUrl":"https://doi.org/10.32047/cwb.2021.26.3.3","url":null,"abstract":"Styrene-butadiene copolymer [SB] modified cement-based materials are widely used, but the addition of SB can delay the setting and hardening of cement, which limits its application in some projects. In this paper, nanosilica was selected as the modifying component to study its influence on the early hydration, setting and hardening of SB/cement composite material. By measuring the setting time and early strength of nanosilica modified SB/cement composite material, the influence of nanosilica on the setting and hardening process of composite cementitious material was analyzed. The hydration heat of nanosilica modified SB/cement composite material was determined by isothermal calorimetry, and its hydration products were examined by X-ray diffraction, so as to analyze the influence of nanosilica on the early hydration process of composite cementitious material. The results show that the addition of nanosilica can effectively promote the setting and hardening process of composite cementitious material, and the higher the dosage is, the more significant the effect is. It also indicates that addition of nanosilica accelerates the formation of ettringite and calcium hydroxide, by promoting the hydration of tricalcium aluminate and tricalcium silicate. Shortens the hydration induction period and acceleration period of the composite cementitious material and accelerates the hydration process, thereby shortening the setting time and increasing the early strength.","PeriodicalId":55632,"journal":{"name":"Cement Wapno Beton","volume":"194 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76784299","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