Study of the effect of alkalis on the slag cement systems

2005 ◽  
Vol 32 (5) ◽  
pp. 934-939 ◽  
Author(s):  
L Zeghichi ◽  
B Mezghiche ◽  
R Chebili
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Construction Materials ◽  
Slag Cement ◽  
Steam Curing ◽  
Hardening Process ◽  
New Construction ◽  
Furnace Slag ◽  
By Products

The replacement of natural materials by industrial by-products has given a variety of new construction materials that are economically viable and ecologically beneficial. Blast furnace slag is one of these industrial by-products. Its beneficial proprieties and characteristics have led to rapid growth of production in Algeria and worldwide. This research deals with the effect of alkaline activation of slag cement with clinker. Various agents that activate the process were used for testing, and it showed that compressive strength at 28 d, which reached 150% with respect to compressive strength obtained from slag cement at different percentages of slag (50%–80%), increased considerably. Alkaline activators accelerate hydration and stimulate the hardening process. The results also show the efficacy of steam cured treatment on the compressive strength.Key words: slag cement, activation agent, hydration, hardening, steam curing.

scholarly journals Alkali-activated concretes based on fly ash and blast furnace slag: Compressive strength, water absorption and chloride permeability

2020 ◽  
Vol 40 (2) ◽  
Author(s):  
Daniela Eugenia Angulo-Ramírez ◽  
William Gustavo Valencia-Saavedra ◽  
Ruby Mejía de Gutiérrez
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Fly Ash ◽  
Water Absorption ◽  
Blast Furnace Slag ◽  
Construction Materials ◽  
Chloride Ion ◽  
Chloride Permeability ◽  
Alkaline Activator ◽  
Furnace Slag

Concretes based on alkaliactivated binders have attracted considerable attention as new alternative construction materials, which can substitute Portland Cement (OPC) in several applications. These binders are obtained through the chemical reaction between an alkaline activator and reactive aluminosilicate materials, also named precursors. Commonly used precursors are fly ash (FA), blast furnace slag (GBFS), and metakaolin. The present study evaluated properties such as compressive strength, rate of water absorption (sorptivity), and chloride permeability in two types of alkaliactivated concretes (AAC): FA/GBFS 80/20 and GBFS/OPC 80/20. OPC and GBFS/OPC* concretes without alkaliactivation were used as reference materials. The highest compressive strength was observed in the FA/GBFS concrete, which reported 26,1% greater strength compared to OPC concrete after 28 days of curing. The compressive strength of alkaliactivated FA/GBFS 80/20 and GBFS/OPC 80/20 was 61 MPa and 42 MPa at 360 days of curing, respectively. These AAC showed low permeability to the chloride ion and a reduced water absorption. It is concluded that these materials have suitable properties for various applications in the construction sector.

scholarly journals Mechanical properties and permeability of red mud-blast furnace slag-based geopolymer concrete

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Xiangzhou Liang ◽  
Yongsheng Ji
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Blast Furnace ◽  
Red Mud ◽  
Blast Furnace Slag ◽  
Construction Materials ◽  
Geopolymer Concrete ◽  
Reaction Products ◽  
Alumina Production ◽  
Furnace Slag

AbstractRed mud, a by-product of alumina production, has a great impact on the environment due to its high alkalinity. In this paper, two-part geopolymer mortar was synthesized by combining red mud and blast furnace slag (BFS) to obtain optimized compressive strength and flexural strength for construction materials. Geopolymer concrete was prepared with the cementitious material in the concrete replaced by geopolymer mortar. Mechanical properties, permeability and microscopic properties of geopolymer concrete were measured. The results showed that the compressive strength grade of concrete prepared with geopolymer concrete can reach 54.43 MPa indicating that the geopolymer concrete can be used as materials for load-bearing members in structures. Due to lower total porosity and better pore structure, the permeability resistance of geopolymer concrete was significantly better than ordinary concrete. Microscopic analysis indicated that a large amount of aluminosilicate reaction products was generated in a geopolymer by the reaction of OH− with the aluminosilicate components in red mud and BFS in a strongly alkaline environment. The surface [SiO4]4− and [AlO4]4− tetrahedrons form chemical bonds through dehydroxylation, which is the direct reason for their high strength and determines their excellent physical and chemical properties.

scholarly journals CONCRETE PROPERTIES OF COMPRESSIVE STRENGTH IN STRUCTURE WITH HIGH VOLUME BLAST FURNACE SLAG CEMENT

2017 ◽  
Vol 23 (54) ◽  
pp. 363-368
Author(s):  
Kazuhisa YODA ◽  
Tetsushi KANDA ◽  
Jinhwan JEON ◽  
Haruki MOMOSE ◽  
Hideki TANAKA
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Blast Furnace Slag ◽  
High Volume ◽  
Slag Cement ◽  
Concrete Properties ◽  
Furnace Slag

scholarly journals Compressive Strength and Durability of FGD Gypsum-Based Mortars Blended with Ground Granulated Blast Furnace Slag

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3383
Author(s):  
Min Pang ◽  
Zhenping Sun ◽  
Huihao Huang
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Raw Materials ◽  
Steam Curing ◽  
Curing Conditions ◽  
Fgd Gypsum ◽  
Granulated Blast Furnace Slag ◽  
Mix Proportion ◽  
Furnace Slag

One new flue gas desulfurization (FGD) gypsum-based binder is attempted in this article, which is made up of FGD gypsum, ground granulated blast furnace slag (GGBS) and ordinary Portland cement (OPC). Influences of raw materials, chemical activators, and curing conditions on the compressive strength of this new binder-based mortar, as well as its durability performances and microscopic characteristics, are investigated in consideration of utilizing FGD gypsum as much as possible. Results show that the compressive strength of this new binder-based mortar under normal curing conditions could increase along with GGBS dosages from three days to 90 days. The compressive strength of one selected mix proportion (FG-4550), which contains the highest dosage of FGD gypsum (45 wt.%), is much the same as those containing the highest dosage of GGBS. A better compressive strength of FG-4550 under normal curing conditions could be gained if the fineness of GGBS is improved. The activated effect of CaCl2 on the compressive strength of FG-4550 is superior to that of Ca(OH)2 under steam curing conditions. FG-4550 shows a good capacity for resistance to water, a low shrinkage ratio, but poor compressive strength after 30 freeze-thaw cycles. Based on the mineralogy of X-ray diffraction, the morphology of scanning electron microscopy and the pore diameter distributions of 1H nuclear magnetic resonance, the compressive strength of this FGD gypsum-based mortar mainly depends on clusters of ettringite.

ON THE USE OF SLAG CEMENT COMPOSITIONS IN THE CONSTRUCTION OF WELLS

2017 ◽  
pp. 80-85
Author(s):  
V. P. Ovchinnikov ◽  
O. V. Rozhkova ◽  
N. A. Aksenova ◽  
P. V. Ovchinnikov
Keyword(s):  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Elevated Temperatures ◽  
Cement Mortar ◽  
Setting Time ◽  
Rheological Parameters ◽  
Slag Cement ◽  
Furnace Slag

In the article studies of oil-filled compositions with the addition of blast-furnace slag for strength at elevated temperatures are presented. The rheological parameters of the slag cement slag cement mortar, as well as the setting time, were studied. Conclusions are drawn about the prospects of further study of slag cementcontaining compositions.

The Influence of the Properties of the Material Used for Obtaining Geopolymers on Their Structure and Compressive Strength

2017 ◽  
Vol 68 (6) ◽  
pp. 1182-1187
Author(s):  
Ilenuta Severin ◽  
Maria Vlad
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Wheat Straw ◽  
Red Mud ◽  
Blast Furnace Slag ◽  
Complex Structure ◽  
Point Of View ◽  
Granulated Blast Furnace Slag ◽  
Furnace Slag ◽  
Straw Ash

This article presents the influence of the properties of the materials in the geopolymeric mixture, ground granulated blast furnace slag (GGBFS) + wheat straw ash (WSA) + uncalcined red mud (RMu), and ground granulated blast furnace slag + wheat straw ash + calcined red mud (RMc), over the microstructure and mechanical properties of the synthesised geopolymers. The activation solutions used were a NaOH solution with 8M concentration, and a solution realised from 50%wt NaOH and 50%wt Na2SiO3. The samples were analysed: from the microstructural point of view through SEM microscopy; the chemical composition was determined through EDX analysis; and the compressive strength tests was done for samples tested at 7 and 28 days, respectively. The SEM micrographies of the geopolymers have highlighted a complex structure and an variable compressive strength. Compressive strength varied from 24 MPa in the case of the same recipe obtained from 70% of GGBFS + 25% WSA +5% RMu, alkaline activated with NaOH 8M (7 days testing) to 85 MPa in the case of the recipe but replacing RMu with RMc with calcined red mud, alkaline activated with the 50%wt NaOH and 50%wt Na2SiO3 solution (28 days testing). This variation in the sense of the rise in compressive strength can be attributed to the difference in reactivity of the materials used in the recipes, the curing period, the geopolymers structure, and the presence of a lower or higher rate of pores, as well as the alkalinity and the nature of the activation solutions used.

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