scholarly journals BUILDING A SUSTAINABLE WORLD: ECONOMY INDEX OF GEOPOLYMER CONCRETE

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Solomon Oyebisi ◽  
Anthony Ede ◽  
Festus Olutoge ◽  
Olatokunbo Ofuyatan ◽  
Tolulope Alayande
Keyword(s):  
Portland Cement ◽  
Production Cost ◽  
Geopolymer Concrete ◽  
Portland Cement Concrete ◽  
Granulated Blast Furnace Slag ◽  
Structural Deterioration ◽  
Research Findings ◽  
Cost Implications ◽  
Source Materials ◽  
Furnace Slag

Geopolymer concrete offers a considerable solution not only to the environmental problem but also to the structural deterioration confronting the world. But, limited or no study is found on its cost implications. Consequently, this study evaluates the production cost and the economy index of geopolymer concrete (GPC) and compares it with the Portland cement concrete (PCC). Corncob ash (CCA) and ground granulated blast furnace slag (GGBFS) were used as source materials in the production of geopolymer concrete. Alkaline liquids were prepared to obtain 12 molar concentrations. The concentration was used to activate the source materials. Grade 30 concrete (M30) was adopted as a mix design proportion. GGBFS was replaced by CCA in varying percentages as 0%, 20%, 40%, 60%, 80%, and 100%. The research findings reveal that GPC is 27.71% lesser than the PCC in terms of production cost while the economy index of GPC is higher than the PCC for the same grade of concrete. The results infer that GPC is cheaper and more viable than the PCC. Thus, geopolymer concrete proves to be an innovative product and appears to be a feasible solution not only to the environmental and structural deteriorating problems but also to the problem of high cost of Portland cement in the construction industry.

scholarly journals Relationship between amorphous silica in source materials and compressive strength of geopolymer concrete

2018 ◽  
Vol 162 ◽  
pp. 02019
Author(s):  
Basil Al-Shathr ◽  
Mohamed Shamsa ◽  
Tareq al-Attar
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Amorphous Silica ◽  
Xrd Analysis ◽  
Geopolymer Concrete ◽  
Portland Cement Concrete ◽  
Granulated Blast Furnace Slag ◽  
Cement Manufacture ◽  
The Relationship ◽  
Source Materials

Geopolymer is a new sustainable binding material. It was developed to reduce CO2 footprint of existing Portland cement concrete. One ton of Geopolymeric cement generates 0.18 ton of CO2 from combustion carbon-fuel. This figure is 6 times less than the emission of Portland cement manufacture. The relationship between the compressive strength of Geopolymer concrete and the percentage of amorphous silica in the source material has been studied in the present work. Six mixes with different source materials were investigated to verify this relationship. The used Pozzolanic materials were three types of Fly ash, two types of Metakaolin and one type of ground granulated blast furnace slag. Geopolymer concrete samples were cured by heating for 72 hours. The testing ages for compressive strength were 7, 14, 28, and 60 days. The results showed that a noticeable relationship between compressive strength and amorphous silica was observed. The microstructure of the six mixes was studied in detail through the SEM and XRD analysis.

scholarly journals Mechanisms Accompanying Chromium Release from Concrete

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1891 ◽  
Author(s):  
Anna Król
Keyword(s):  
Portland Cement ◽  
Building Materials ◽  
Portland Cement Concrete ◽  
Chromium Release ◽  
Granulated Blast Furnace Slag ◽  
Diffusion Controlled ◽  
Tank Test ◽  
Mineral Additives ◽  
Furnace Slag

The use of mineral additives from the power and metallurgy industries in the production of building materials still raises questions about the ecological safety of such materials. These questions are particularly associated with the release of heavy metals. The article presents research related to the leaching of chromium from concretes made of Portland cement CEM I and slag cement CEM III/B (containing 75% of granulated blast furnace slag). Concrete was evaluated for leaching mechanisms that may appear during tank test over the long term (64 days). It has been presented that the dominating process associated with the leaching of chromium from both types of concrete is surface wash-off. Between the 9th and 64th day of the test, leaching of Portland cement concrete can be diffusion controlled. It has been proven that the participation of slag in the composition of concrete does not affect the level of leaching of chromium into the environment from concrete.

Calorimetric determination of the effect of additives on cement hydration process

2013 ◽  
Vol 67 (2) ◽  
Author(s):  
Pavel Šiler ◽  
Josef Krátký ◽  
Iva Kolářová ◽  
Jaromír Havlica ◽  
Jiří Brandštetr
Keyword(s):  
Portland Cement ◽  
Silica Fume ◽  
Maximum Temperature ◽  
Granulated Blast Furnace Slag ◽  
Mineral Components ◽  
Maximum Temperatures ◽  
The Impact ◽  
Furnace Slag ◽  
Calorimetric Determination

AbstractPossibilities of a multicell isoperibolic-semiadiabatic calorimeter application for the measurement of hydration heat and maximum temperature reached in mixtures of various compositions during their setting and early stages of hardening are presented. Measurements were aimed to determine the impact of selected components’ content on the course of ordinary Portland cement (OPC) hydration. The following components were selected for the determination of the hydration behaviour in mixtures: very finely ground granulated blast furnace slag (GBFS), silica fume (microsilica, SF), finely ground quartz sand (FGQ), and calcined bauxite (CB). A commercial polycarboxylate type superplasticizer was also added to the selected mixtures. All maximum temperatures measured for selected mineral components were lower than that reached for cement. The maximum temperature increased with the decreasing amount of components in the mixture for all components except for silica fume. For all components, except for CB, the values of total released heat were higher than those for pure Portland cement samples.

scholarly journals Effect of Na2SiO3/Naoh on the Compressive Strength of Inorganic Polymer Concrete Mixed with Ground Granulated Blast Furnace Slag (GGBS) At Ambient Condition

2019 ◽  
Vol 9 (2) ◽  
pp. 1222-1228
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Ambient Condition ◽  
Polymer Concrete ◽  
Geopolymer Concrete ◽  
Split Tensile Strength ◽  
Standard Size ◽  
Granulated Blast Furnace Slag ◽  
Furnace Slag

This paper aims to investigate the influence of alkaline activators solution i.e, Na2SiO3 / NaOH on compressive strength of geopolymer concrete mixed with Ground Granulated Blast furnace slag (GGBS) for constant molarity 8 M. The ratio of alkali to binder ratio is taken as 0.5 and the ratio of Na2SiO3 / NaOH is 2.5. The geopolymer mix is based on pervious sutdies. As per Indian standard size moulds for the cube, cylinder and prism are cast, cured and tested.The specimens were tested for fresh concrete properties such as slump cone test and hardened properties such as compressive strength for cubes, split tensile strength for cylinders and flexural strength for prism different days of curing under ambient temperature. Also, a microstructural study is done by using Scanning electron microscopy (SEM), Energy dispersive X-ray (EDX) for the tested sample. It is found from the test results that, with the aid of alumino-silicate solution, early strength is achieved by geopolymer concrete within 7 days under ambient condition due to the presence of ground granulated slag.

scholarly journals MICRO-MECHANICAL PROPERTIES OF CEMENT AND SLAG COMPOSITES MEASURED BY NANOINDENTATION

2020 ◽  
Vol 26 ◽  
pp. 45-49
Author(s):  
Jiří Němeček ◽  
Jiří Němeček
Keyword(s):  
Mechanical Properties ◽  
Portland Cement ◽  
Modulus Of Elasticity ◽  
Volume Fraction ◽  
Blended Cement ◽  
Hydration Products ◽  
Granulated Blast Furnace Slag ◽  
The Difference ◽  
Portland Cement Paste ◽  
Furnace Slag

In this study, the micromechanical response of two cementitious composites was characterized by nanoindentation. Pure Portland cement paste and Portland cement with 50 vol. % replaced with granulated blast furnace slag (GBFS) paste were investigated at the age of 28 days. Grid nanoindentation, statistical deconvolution and scanning electron microscopy were used to characterize the main hydration products. Several grids with approximately 500 indents on each sample were performed to obtain modulus of elasticity, hardness and creep indentation parameter. Similar mechanical phases containing calcium silica hydrate, crystalline calcium hydroxide and un-hydrated clinker were found in both samples varying by volume fraction. Blended cement, moreover, contains a phase of slag hydration products with a significantly lower modulus of elasticity. This phase with a high portion of unreacted GBFS is mostly responsible for the difference of mechanical properties of the whole composite.

Alkali-Activated EAF Reducing Slag as Binder for Concrete

2013 ◽  
Vol 723 ◽  
pp. 580-587
Author(s):  
Wen Huan Zhong ◽  
Tung Hsuan Lu ◽  
Wei Hsing Huang
Keyword(s):  
Portland Cement ◽  
Drying Shrinkage ◽  
Portland Cement Concrete ◽  
Steel Making ◽  
Chemical Content ◽  
Alkaline Activator ◽  
Furnace Slag ◽  
Alkali Activated ◽  
Better Than

Electric arc furnace (EAF) reducing slag is the by-product of EAF steel-making. Currently, reducing slag is considered a waste material by the industry in Taiwan. Since the chemical content of reducing slag is similar to blast furnace slag (BFS), it is expected that reducing slag exhibits a similar pozzolanic effect as the BFS. This study used alkaline activator consisting of sodium silicate and sodium hydroxide to improve the activity of reductive slag so as to replace Portland cement as binder in concrete. Some BFS was used to blend with the reducing slag to enhance the binding quality of alkali-activated mixes. The results show that a blend of 50% BFS and 50% reducing slag can be activated successively with alkali. Also, the sulfate resistance of concrete made with alkali-activated EAF reducing slag is found to be better than that of concrete made with portland cement, while the drying shrinkage of alkali-activated EAF reducing slag concrete is greater than that of portland cement concrete.

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