scholarly journals Study of the Suitability of Different Types of Slag and Its Influence on the Quality of Green Grouts Obtained by Partial Replacement of Cement

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1166 ◽  
Author(s):  
Francisca Perez-Garcia ◽  
Maria Eugenia Parron-Rubio ◽  
Jose Manuel Garcia-Manrique ◽  
Maria Dolores Rubio-Cintas

This paper is part of a research line focused on the reduction of the use of cement in the industry. In this work, the study of work methodologies for the manufacture of green cementitious grout mixtures is studied. Grout is widely used in construction and it requires an important use of raw materials. On the other hand, the steel industry faces the problem of the growing generation of slag wastes due to the increase in steel manufacturing. The green grout aims to achieve the dual objective of reducing the demand for cement and improve the slag waste valorization. Slag is not introduced as an aggregate but through the direct replacement of cement and no additives. The research seeks a product where we can use steel slag intensively, guaranteeing minimum resistance and workability. Results with substitutions between a 25% to 50% and water/cement ratio of 1 are presented. In particular, the suitability of different slags (two Ladle Furnace Slag (LFS) and one Blast Furnace Slag (GGBS)) in the quality of the final product are analyzed. The feasibility of replacing cement with slag and the importance of the origin and pretreatment are highlighted.

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 561
Author(s):  
Francisca Perez-Garcia ◽  
Maria Dolores Rubio-Cintas ◽  
Maria Eugenia Parron-Rubio ◽  
Jose Manuel Garcia-Manrique

This article presents a study of the main properties (consistency, workability, leaching, unsoundness, and mechanical properties) of cement grouts prepared with cement replacement by blast furnace slag (GGBS). Mixtures have been analyzed in the absence of additives and reached high replacement percentages. As shown in the different tests presented, the observed evolution of the resistance and workability of the mixtures makes them very interesting for its application. Different types of cement (CEM-I 42.5 and CEM-I 52.5 R) and different water/binder values (1 and 0.67) are used. The results present opportunities for the steel industry by the intensive valorization of slag waste. The reduction of the use of cement in construction is also one of the key aims of this line of research. Results show improvements in the mechanical response with good fresh state properties for substitution percentages up to 70%. It is verified with leaching analysis that these products have less impact on the environment.


Author(s):  
Łukasz Majewski ◽  
Roman Jaskulski ◽  
Wojciech Kubissa

The article presents the results of testing the effect of partial replacement of sand with fine copper slag waste on the thermal properties of hardened concrete. The impact of the replacement on mechanical properties (ie. compressive and tensile strength of concrete) was also investigated. The thermal properties of the concrete were determined using the non-stationary method with the ISOMET 2114 device. Tests were performed on concrete containing three different types of cement (CEM I, CEM II and CEM III). A total cement content of 360 kg/m3 was assumed in the compositions of all concrete mixes with a water-cement ratio of 0.45. Replacing 66% of the sand volume with copper slag waste caused a decrease in thermal conductivity by about 4–8% in relation to the reference concrete. In addition, the compressive strength of concrete containing copper slag increased by about from 4–21% in relation to the reference concrete.


2021 ◽  
pp. 104-113
Author(s):  
O. P. Deryugina ◽  
E. A. Trapeznikov

The article discusses the issue of industrial compounding, which improves the quality of the raw materials supplied to the main pipelines. Compounding from "to compound" (English) - to mix. When mixing different types of oil obtained, "incompatibility" is possible, which is expressed in the precipitation of a solid sediment and violation of the stability of the colloidal system and due to the differing properties of oils. Attention to this problem is due to the tightening of requirements for the quality of raw materials that must comply with modern standards. The article discusses the causes of the problem of "incompatibility" of oil during compounding and effective ways of solving it, substantiates the need for a preliminary study of the properties of mixed oil in order to identify possible incompatibility of various types of oil. The standard tests for determination of incompatibility indices characterizing the ability of raw materials to mix are considered. The article substantiates the need to develop methods for diagnosing the incompatibility of oils as the most important task of modern chemical science, the solution of which will improve the quality of the raw material obtained and solve many technological problems in the compounding process.


Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 6 ◽  
Author(s):  
Wei-Ting Lin ◽  
Chia-Jung Tsai ◽  
Jie Chen ◽  
Weidong Liu

Basic oxygen furnace slag (BOFS) was ground to three levels of fineness as a replacement for cement at weight proportions of 10, 30, 50, and 70 wt.%. Fineness and weight proportion were shown to have significant effects on the flowability and setting time of the mortars. The expansion of BOFS mortars increased with an increase in the proportion of cement replaced, thereby exacerbating the effects of cracking. Optimal mechanical properties were achieved when 10 wt.% of the cement was replaced using BOFS with fineness of 10,000 cm2/g. The compressive strength of BOFS mortar is similar to that of ordinary Portland mortar, which makes BOFS suitable for the partial replacement of cement as a supplementary cementitious material. Scanning electron microscopy results revealed that the reaction of CaO with H2O results in the formation of C–S–H colloids, whereas the reaction of SiO2 with Al2O3 produces C–A–S–H colloids. The use of BOFS as a partial replacement for Portland cement could make a tremendous contribution to the steel industry and help to lower CO2 emissions.


2010 ◽  
Vol 163-167 ◽  
pp. 1651-1654 ◽  
Author(s):  
Jin Bang Wang ◽  
Zong Hui Zhou

Several series of concrete aggregates with different content of steel slag, blast furnace slag, coal gangue and fly ash were prepared. The reasonable ratio of raw materials and process parameters to prepare the aggregates were determined by measuring the water absorption, crush indicators and apparent density of the aggregates. The mineral composition and morphology of the aggregates were analyzed by XRD, SEM and EDS. The results showed the aggregate with about 30% steel slag, 50% slag, 20% gangue, and calcined at 1300°C for 90 minutes had the best performance. The water absorption of the aggregate is about 1.55% which is lower than that of the natural aggregates (about 2.2% on average). Both the crushing index (about 11.39%) and the apparent density (2672 kg/m3) of the aggregate meet the requirements of national standards.


2019 ◽  
Vol 814 ◽  
pp. 413-418
Author(s):  
Fang Wang ◽  
Ming Han Xu ◽  
Rui Hua Wang ◽  
Chao Yang ◽  
Ai Xia Chen ◽  
...  

The construction industry continues to develop and the requirements for cement performance are getting higher and higher. At the same time, in the steel industry, the discharge of steel slag is also increasing. The effective reuse of steel slag has become a prominent problem in the steel industry. . Therefore, it is envisaged to use steel slag as a raw material for the cement production process to produce cement and to produce high-performance cement. The main raw materials of this experiment are steel slag, limestone, sandstone and shale. Through the cement preparation process, the cement is made, and then the cement is made into concrete to test its performance. This experiment mainly studies the sintering temperature and holding time variable. In the experimental test, the analysis and comparison were carried out in five aspects of the degree of macroscopic cracking, particle size, density, microstructure and composition. In the comparison experiment of sintering temperature, with the increase of temperature, the flexural and compressive properties of cement gradually increased. In this test, 1200 °C is the most suitable temperature for the performance of the cement. Through the experimental comparison of different holding time, it is known that with the prolonging of the holding time, the microstructure and actual performance of the cement are continuously enhanced. Comprehensive consideration: the ratio of steel slag in cement ratio is 10%, sintering temperature is 1200 °C, and heat preservation is 2h. The steel slag cement prepared under this condition has the strongest performance.


2013 ◽  
Vol 743-744 ◽  
pp. 180-185
Author(s):  
Jun Hua Zhang ◽  
Zong Hui Zhou ◽  
De Cheng Zhang ◽  
Xin Cheng

Artificial aggregates with high-performance were prepared by the methods including steel slag, furnace slag, fly ash and coal gangue, and the recycling concrete was prepared by artificial aggregates instead of natural aggregates. This kind of concrete abandoned was able to completely regenerate cement, which will make the reuse of concrete possible. The composition and characteristics of the artificial aggregates will produce a significant effect on the interfacial transition zone (ITZ) in recycling concrete. The morphological features and mineral composition of three artificial aggregates were analyzed by SEM and XRD, and the ITZ of three recycling concrete and one ordinary concrete was investigated by SEM and EDS. The results showed that compared with ordinary concrete, although the recycling concretes ITZ had a small amount of CH crystal, most of the space was filled with dense hydration products. The interface width was 40μm, which less than 50μm of ordinary concrete. Artificial aggregates with different ratio of raw materials had a great effect on recycling concretes ITZ. The ITZ of recycling concrete prepared with 30% steel slag, 50% furnace slag, 20% fly ash had the smallest Ca/Si and much more C-S-H. the structure of ITZ was much denser and the microstructure was relatively better.


2021 ◽  
Vol 9 (2) ◽  
pp. 53-57
Author(s):  
Osama Daoud ◽  
Muntasir Ibrahim

This research paper focuses on the possibility of utilization of Giad electric arc furnace slag (GEAFS) as a partial replacement for coarse aggregates in concrete, without compromising on its workability and strength. The electric arc furnace slag is a waste product from the steel manufacturing which may be used as partial replacement of coarse aggregates in concrete. This paper presents an experimental study on fresh and hardened properties of concrete containing steel slag aggregates. Slump, as well as strength properties of concrete prepared with natural coarse aggregate, partially replaced by the GEAFS in different proportions varying from 25 %, 50 % and 75 %. The GEAFS concrete shows marginal decrease in slump for the further replacement. Compressive, split and Flexural strength of the GEAFS concrete have been increased for the GEAFS addition. Highest compressive, tensile and flexural strength have been achieved by the mix containing 50 % GEAFS coarse aggregates. Using of steel slag will result in decrease of waste landfilling, and improving environmental condition.  


Author(s):  
G. Р. Khomych ◽  
N. I. Tkach ◽  
Y. G. Nakonechna ◽  
O. V. Nesterenko ◽  
N. M. Prior

The article considers the use of Jerusalem artichoke processing products in technology flour yeast products. In terms of productivity, Jerusalem artichokes significantly exceed potatoes, sugar beets, corn and other crops of intensive type, but grow it on small area mainly for fodder purposes. Recently, in the food industry is observed reorientation to the production of products with new qualities, aimed at improving the situation health and disease prevention. Jerusalem artichoke is a unique raw material that can increase the biological value of finished products. Useful properties of Jerusalem artichoke are used to strengthen the immune system, reduce the risk of heart attack and stroke, eliminate salt deposits in the joints, in the therapeutic diet for diabetes. However, its limited use in the processing industry is due to the rapid enzymatic darkening of Jerusalem artichoke tubers during processing. Given the specific properties of Jerusalem artichoke, it is advisable to investigate the enzymatic darkening of Jerusalem artichoke tubers during processing by determining the activity of the enzyme polyphenol oxidase and the use of Jerusalem artichoke puree in the technology of yeast dough. Analysis of tubers and Jerusalem artichoke puree was performed by organoleptic and physicochemical indicators. The quality of finished products was controlled by organoleptic, physicochemical and structural and mechanical indicators, among which special attention was paid to indicators acidity, humidity, porosity, shape stability. The activity of the enzyme in whole and crushed Jerusalem artichoke tubers and its effect on the activity of the enzyme pre-blanching in water for 10 minutes It is determined that when blanching is a partial inactivation of the enzyme polyphenol oxidase, which prevents darkening of raw materials during grinding. The effect of adding Jerusalem artichoke puree in the amount of 10, 15 and 20 % was studied on gluten of wheat flour. The partial replacement of wheat flour in mashed Jerusalem artichoke leads not only to a decrease in the amount of gluten, but also to a change in its quality. The gluten becomes more elastic, the extensibility decreases, and with the addition of 20 % puree gluten is torn. It is determined that the duration of fermentation of dough samples varies depending on the amount introduced Jerusalem artichoke puree. With increasing percentage of Jerusalem artichoke puree in the dough recipe, the duration of dough fermentation is reduced by 6.25…8.75 %. The addition of puree had a positive effect Jerusalem artichoke to increase the yield of the finished product by 5.20…26.34 %. Research of the main quality indicators of experimental samples confirm that according to the set of indicators, the optimal sample is 10 % of Jerusalem artichoke puree, which makes it possible to recommend it for the production of yeast bakery products of high biological value.


2020 ◽  
Vol 12 (23) ◽  
pp. 9873
Author(s):  
Vojtěch Václavík ◽  
Marcela Ondová ◽  
Tomáš Dvorský ◽  
Adriana Eštoková ◽  
Martina Fabiánová ◽  
...  

Sustainability in the construction industry refers to all resource-efficient and environmentally responsible processes throughout the life cycle of a structure. Green buildings may incorporate reused, recycled, or recovered materials in their construction. Concrete is as an important building material. Due to the implementation of by-products and waste from various industries into its structure, concrete represents a significant sustainable material. Steel slag has great potential for its reuse in concrete production. Despite its volume changes over time, steel slag can be applied in concrete as a cement replacement (normally) or as a substitute for natural aggregates (rarely). This paper focused on an investigation of concrete with steel slag as a substitute of natural gravel aggregate. Testing physical and mechanical properties of nontraditional concrete with steel slag as a substitute for natural aggregates of 4/8 mm and 8/16 mm fractions confirmed the possibility of using slag as a partial replacement of natural aggregate. Several samples of concrete with steel slag achieved even better mechanical parameters (e.g., compressive strength, frost resistance) than samples with natural aggregate. Moreover, a life cycle assessment (LCA) was performed within the system boundaries cradle-to-gate. The LCA results showed that replacements of natural aggregates significantly affected the utilization rate of nonrenewable raw materials and reduced the overall negative impacts of concrete on the environment up to 7%. The sustainability indicators (SUI), which considered the LCA data together with the technical parameters of concrete, were set to evaluate sustainability of the analyzed concretes. Based on the SUI results, replacing only one fraction of natural gravel aggregate in concrete was a more sustainable solution than replacing both fractions at once. These results confirmed the benefits of using waste to produce sustainable materials in construction industry.


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