scholarly journals Use of GGBS as Partial Replacement of Cement in Concrete While using Master REHO Build 823PQ

Currently cement is the most important material in the construction sector. Ordinary Portland cement is one of the main ingredients used for the production of concrete. Unfortunately, production of cement involves emission of large amounts of carbon-dioxide gas into the atmosphere, a major contributor of greenhouse effect and consequent global warming. While, cement typically comprises only 12% of the concrete mass, it accounts for approximately 93% of the total embodied energy of concrete and 6% to 7% of the world wide Carbon dioxide (CO2 ) emissions. Hence, it is of utmost importance to either search for another cementitious material or partially replace it by some other material. Currently there is a trend of usage of waste products such as fly ash from coal industries, GGBS from iron smelting process, paper ash from paper industry etc as supplementary cementitious materials to enhance the properties of concrete while also effectively reducing the carbon foot print. Ground Granulated Blast Furnace Slag (GGBS) is a by-product from iron smelting process using the blast-furnace. The present paper is prepared to study the effect on compressive strength of concrete due to partial replacement of cement with GGBS as supplementary cementitious material while using master REHO build 823PQ.

2007 ◽  
Vol 34 (7) ◽  
pp. 793-802 ◽  
Author(s):  
Said Laldji ◽  
Arezki Tagnit-Hamou

With today's requirements for high-performance concrete, mix proportions containing cementitious materials as partial replacement of, or in addition to, Portland cement, are being used more frequently. The most commonly used cementitious materials nowadays are fly ash, silica fume, and ground, granulated blast-furnace slag. However, alternative supplementary cementitious materials can successfully be used as long as they meet the acceptance criteria stated in various specifications. This paper provides data on properties of structural concrete containing glass frit. The performance of this type of concrete is highlighted by its rheological and mechanical behaviour, as well as its durability. Later-age compressive, splitting tensile, and flexural strengths are well above estimated values, and in many cases, are higher than those obtained with the control concrete. Durability aspects and characteristics expressed by drying shrinkage, surface scaling, and chloride-ion permeability have shown that concrete incorporating glass frit has a very good potential for long-term resistance.Key words: glass frit, cementitious material, workability, mechanical properties, durability.


2017 ◽  
Vol 744 ◽  
pp. 136-140 ◽  
Author(s):  
Osama Ahmed Mohamed ◽  
Modafar Ati ◽  
Omar Fawwaz Najm

The adverse environmental impact of the construction industry may be mitigated through the partial replacement of cement with supplementary cementitious materials (SCM). SCMs such as ground granulated blast furnace slag (GGBS), impart many favourable fresh and long-term concrete properties. A study by Mohamed [1] assessed the splitting tensile strength of sustainable self- consolidating concrete in which up to 80% of the cement was partially replaced with ground granulated blast furnace slag (GGBS), and developed a prediction formula for the splitting tensile strength. In this paper, the tensile strength prediction formula developed by Mohamed et al. [1] is benchmarked against formulas proposed in different building codes and validated with additional test results obtained from the literature. The proposed prediction formula showed excellent correlation to experimental data obtained from the literature.


2021 ◽  
Vol 11 (9) ◽  
pp. 4028
Author(s):  
Asghar Gholizadeh Vayghan ◽  
Liesbeth Horckmans ◽  
Ruben Snellings ◽  
Arne Peys ◽  
Priscilla Teck ◽  
...  

This research investigated the possibility of using metallurgical slags from the copper and lead industries as partial replacement for cement. The studied slags were fayalitic, having a mainly ferro-silicate composition with minor contents of Al2O3 and CaO. The slags were treated at 1200–1300 °C (to reduce the heavy metal content) and then granulated in water to promote the formation of reactive phases. A full hydration study was carried out to assess the kinetics of reactions, the phases formed during hydration, the reactivity of the slags and their strength activity as supplementary cementitious material (SCM). The batch-leaching behaviour of cementitious mixtures incorporating treated slags was also investigated. The results showed that all three slags have satisfactory leaching behaviour and similar performance in terms of reactivity and contribution to the strength development. All slags were found to have mediocre reactivity and contribution to strength, especially at early ages. Nonetheless, they passed the minimum mechanical performance requirements and were found to qualify for use in cement.


Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3467
Author(s):  
Ankit Kothari ◽  
Karin Habermehl-Cwirzen ◽  
Hans Hedlund ◽  
Andrzej Cwirzen

Most of the currently used concretes are based on ordinary Portland cement (OPC) which results in a high carbon dioxide footprint and thus has a negative environmental impact. Replacing OPCs, partially or fully by ecological binders, i.e., supplementary cementitious materials (SCMs) or alternative binders, aims to decrease the carbon dioxide footprint. Both solutions introduced a number of technological problems, including their performance, when exposed to low, subfreezing temperatures during casting operations and the hardening stage. This review indicates that the present knowledge enables the production of OPC-based concretes at temperatures as low as −10 °C, without the need of any additional measures such as, e.g., heating. Conversely, composite cements containing SCMs or alkali-activated binders (AACs) showed mixed performances, ranging from inferior to superior in comparison with OPC. Most concretes based on composite cements require pre/post heat curing or only a short exposure to sub-zero temperatures. At the same time, certain alkali-activated systems performed very well even at −20 °C without the need for additional curing. Chemical admixtures developed for OPC do not always perform well in other binder systems. This review showed that there is only a limited knowledge on how chemical admixtures work in ecological concretes at low temperatures and how to accelerate the hydration rate of composite cements containing high amounts of SCMs or AACs, when these are cured at subfreezing temperatures.


Author(s):  
O. R. Ogirigbo ◽  
J. O. Ukpata ◽  
I. Inerhunwa

Ground Granulated Blast Furnace Slag (GGBS) is a type of Supplementary Cementitious Material (SCM) that is currently being used extensively in the global construction industry. SCMs are cheaper than Portland cement, help to improve certain properties of concrete and also help to reduce the environmental footprint associated with the production of Portland cement. GGBS is readily available in most parts of the world as a waste product from iron and steel production. However, its use as a SCM in some countries has not been fully maximized. This is primarily because of lack of documented studies on the properties of GGBS that influences its suitability as a SCM, especially in tropical environments. This paper reviewed the use of GGBS as a SCM for the partial replacement of Portland cement, with particular emphasis on its potential use in tropical warm environments such as Nigeria and other similar countries.


2019 ◽  
Vol 292 ◽  
pp. 102-107 ◽  
Author(s):  
Josef Fládr ◽  
Petr Bílý ◽  
Karel Šeps ◽  
Roman Chylík ◽  
Vladimír Hrbek

High-performance concrete is a very specific type of concrete. Its production is sensitive to both the quality of compounds used and the order of addition of particular compounds during the homogenization process. The mechanical properties were observed for four dosing procedures of each of the three tested concrete mixtures. The four dosing procedures were identical for the three mixes. The three mixes varied only in the type of supplementary cementitious material used and in water content. The water content difference was caused by variable k-value of particular additives. The water-to-binder ratio was kept constant for all the concretes. The additives used were metakaolin, fly ash and microsilica. The comparison of particular dosing procedures was carried out on the values of basic mechanical properties of concrete. The paper compares compressive strength and depth of penetration of water under pressure. Besides the comparsion of macro-mechanical properties, the effect of microsilica and fly ash additives on micro-mechanical properties was observed with the use of scanning electron microscopy (SEM) and nanoindentation data analysis. Nanoindentation was used to determine the thickness and strength of interfacial transition zone (ITZ) for different sequence of addition of cement, additive and aggregate. The thickness obtained by nanoindentation was further investigated by SEM EDS line scanning.


2018 ◽  
Vol 7 (2.12) ◽  
pp. 446
Author(s):  
L Krishnaraj ◽  
P T. Ravichandran ◽  
M V.A.Karthik ◽  
N Satheeshram Avudaiyappan ◽  
. .

The life of the concrete is strongly influenced by durability parameters. The permeability is one of the main characteristics influencing the durability of concrete. The concrete is more permeable due to the ingress of water, oxygen, chloride, sulphate, and other potential deleterious substances. The durability of concrete is mainly affected by pore structure system of concrete and addingthe supplementary cementitious materials (SCM), such as fly ash, slag cement, and silica fume can be decrease permeability. Crystalline technology enhances the strength of concrete by filling the poresand micro-cracks with non-dissolvable substances. To study the efficiency of crystalline formation in concrete in terms of more permeable should be guaranteed through a specific technique.The effectiveness of crystalline waterproofing system with partial replacement cement by GGBS is studiedin terms of strength and durability. The performance of the two different types of crystalline waterproofing integral admixtures has been studied for compressive strength, Split tensile strength, workability, water permeability, Rapid chloride permeability test and porosity in this paper.The early strength increased in GGBS with crystalline admixture concretes compare to the control concrete. No significant strength reduction is observed in GGBS concretes with crystalline admixture when replaced with 20% and 40% of cement than control concrete.  


2014 ◽  
Vol 621 ◽  
pp. 30-34
Author(s):  
Eva Vejmelková ◽  
Dana Koňáková ◽  
Monika Čáchová ◽  
Martin Keppert ◽  
Adam Hubáček ◽  
...  

Natural zeolite rocks are known to be able to act as Supplementary Cementitious Materials (SCM) in Portland cement based concrete. Generally SCMs are reacting with portlandite and providing binding hydration products just as Portland cement does. In this way an SCM can substitute certain amount of Portland cement in concrete and thus reduce the related energy consumption and CO2 generation. Due to a large variability of SCMs composition and properties there is not any general rule for an optimum Portland cement substitution level. In this paper, the influence of natural zeolite rock on selected mechanical, hygric and thermal properties of concrete is studied. Experimental results show that the analyzed zeolite is acting as a pozzolan but for higher amounts its application leads to an increase in concrete porosity which affects its properties in a significant way.


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