scholarly journals Evolution of Mechanical Properties with Time of Fly-Ash-Based Geopolymer Mortars under the Effect of Granulated Ground Blast Furnace Slag Addition

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1135 ◽  
Author(s):  
Mateusz Sitarz ◽  
Izabela Hager ◽  
Marta Choińska
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Fly Ash ◽  
Modulus Of Elasticity ◽  
Blast Furnace Slag ◽  
Energy Savings ◽  
Pulse Velocity ◽  
Partial Replacement ◽  
Granulated Blast Furnace Slag ◽  
Furnace Slag

Geopolymers are considered to alternatives to Portland cement, providing an opportunity to exploit aluminosilicate wastes or co-products with promising performances in the construction sector. This research is aimed at investigating the strength of fly-ash-geopolymers of different ages. The effect of granulated blast furnace slag (GGBFS) as a partial replacement of fly ash (FA) on the tensile (ft) and compressive strength (fc), as well as the modulus of elasticity, is investigated. The main advantage of the developed geopolymer mixes containing GGBFS is their ability to set and harden at room temperature with no need for heating to obtain binding properties, reducing the energy consumption of their production processes. This procedure presents a huge advantage over binders requiring heat curing, constituting a significant energy savings and reduction of CO2 emissions. It is found that the development of strength strongly depends on the ratio of fly-ash to granulated blast furnace slag. With the highest amount of GGBFS, the compressive strength of geopolymers made of fly-ash reached 63 MPa after 28 days of curing at ambient temperature. The evolution of compressive strength with time is correlated with the development of ultrasound pulse velocity methods, which are used to evaluate maturity. The modulus of elasticity changes with strength and the relationship obtained for the geopolymer is presented on the basis of typical models used for cement-based materials. The tensile to compressive strength ratios of the tested geopolymers are identified as higher than for cementitious binders, and the ft(fc) relationship is juxtaposed with dependencies known for cement binders, showing that the square root function gives the best fit to the results.

scholarly journals Effect of Polypropylene Fiber, GGBS and Fly Ash over the Strength Aspects of Concrete: A Critical Review

2021 ◽  
Vol 9 (VI) ◽  
pp. 978-983
Author(s):  
Khalid Bashir Mir
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Blast Furnace ◽  
Fly Ash ◽  
Blast Furnace Slag ◽  
Polypropylene Fiber ◽  
Synthetic Fiber ◽  
Partial Replacement ◽  
Granulated Blast Furnace Slag ◽  
Furnace Slag

In this review study the usage of three different kinds of constructional materials was discussed in detail. The three materials comprised of Ground Granulated Blast Furnace Slag, fly and polypropylene fiber. Ground Granulated Blast Furnace Slag is basically the slag derived after the quenching process of iron slag produced during the processing of iron in iron industry. Fly ash is the waste generated from the coal processing industries and is mainly used in the road constructions works. Polypropylene fiber is a synthetic fiber that has very high tensile strength and flexural strength. This fiber is also known as synthetic fiber as it is mainly used in the synthetic industry. Depending upon the results of previous studies over the usage of these materials various conclusions has been drawn which are as follows. The results of studies related to the usage of Ground Granulated Blast Furnace Slag as partial replacement of cement concluded that the most optimum usage percentage of Ground Granulated Blast Furnace Slag as partial replacement of cement was found to be between 20 percent and 30 percent and beyond this limit the strength of concrete was decreasing. The past studies related to the usage of fly ash as partial replacement of cement shoed that the most optimum usage percentage of fly ash was found to be between 15 percent to 20 percent and beyond this percentage the strength parameters of concrete such as compressive strength, flexural strength and split tensile strength starts declining up to a greater extent. The studies related to the usage of polypropylene fiber showed that the usage of this fiber increases the compressive strength of soil and the most optimum results were found between 1.0 percent to 1.5 percent usages of polypropylene fiber. Above this percentage there will be negative effect on the strength aspects and the compressive strength starts declining.

scholarly journals Protective Geopolymer Coatings Containing Multi-Componential Precursors: Preparation and Basic Properties Characterization

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3448
Author(s):  
Chenhui Jiang ◽  
Aiying Wang ◽  
Xufan Bao ◽  
Zefeng Chen ◽  
Tongyuan Ni ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Fly Ash ◽  
Portland Cement ◽  
Adhesive Strength ◽  
Blast Furnace Slag ◽  
Setting Time ◽  
Rapid Test ◽  
Granulated Blast Furnace Slag ◽  
Furnace Slag

This paper presents an experimental investigation on geopolymer coatings (GPC) in terms of surface protection of civil structures. The GPC mixtures were prepared with a quadruple precursor simultaneously containing fly ash (FA), ground granulated blast-furnace slag (GBFS), metakaolin (MK), and Portland cement (OPC). Setting time, compressive along with adhesive strength and permeability, were tested and interpreted from a perspective of potential applications. The preferred GPC with favorable setting time (not shorter than 120 min) and desirable compressive strength (not lower than 35 MPa) was selected from 85 mixture formulations. The results indicate that balancing strength and setting behavior is viable with the aid of the multi-componential precursor and the mixture design based on total molar ratios of key oxides or chemical elements. Adhesive strength of the optimized GPC mixtures was ranged from 1.5 to 3.4 MPa. The induced charge passed based on a rapid test of coated concrete specimens with the preferred GPC was 30% lower than that of the uncoated ones. Setting time of GPC was positively correlated with η[Si/(Na+Al)]. An abrupt increase of setting time occurred when the molar ratio was greater than 1.1. Compressive strength of GPC was positively affected by mass contents of ground granulated blast furnace slag, metakaolin and ordinary Portland cement, and was negatively affected by mass content of fly ash, respectively. Sustained seawater immersion impaired the strength of GPC to a negligible extent. Overall, GPC potentially serves a double purpose of satisfying the usage requirements and achieving a cleaner future.

Development of High Performance Concrete Containing Admixture in Nuclear Power Plants

2013 ◽  
Vol 357-360 ◽  
pp. 1062-1065 ◽  
Author(s):  
Jeong Eun Kim ◽  
Wan Shin Park ◽  
Song Hui Yun ◽  
Do Gyeum Kim ◽  
Jea Myoung Noh
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Blast Furnace ◽  
Fly Ash ◽  
Silica Fume ◽  
Modulus Of Elasticity ◽  
Blast Furnace Slag ◽  
High Performance ◽  
Splitting Tensile Strength ◽  
Furnace Slag

This paper presents the results of an experimental study on the compressive strength, splitting tensile strength and modulus of elasticity characteristics of high performance concrete. These tests were carried out to evaluate the mechanical properties of HPC for up to 7 and 28 days. Mixtures were prepared with water to binder ratio of 0.40. Two mixtures were containing fly ash at 25%, silica fume at 5% cement replacement, respectively. Another mixture was contains blast furnace slag and fly ash at 25%. Three standard 100¥a200 cylinder specimens were prepared. HPC showed improvement in the compressive strength and splitting tensile strength when ordinary Portland cement was replaced with silica fume. Compare with specimens FA25 and BS25FA25, specimen SF5 showed much more modulus of elasticity. It shows that the use of the blast furnace slag of 25% and fly ash of 25% cement replacement has caused a small increase in compressive strength and splitting tensile strength and modulus of elasticity compared to the only use of fly ash of 25% at 28days. The results indicated that the use of blast furnace slag or silica fume provided the good performance compare to fly ash when the mechanical properties of the high performance concretes were taken into account.

scholarly journals Investigation of Mechanical Properties, Durability and Microstructure of Low-Clinker High-Performance Concretes Incorporating Ground Granulated Blast Furnace Slag, Siliceous Fly Ash and Silica Fume

2021 ◽  
Vol 11 (2) ◽  
pp. 830
Author(s):  
Katarzyna Konieczna ◽  
Karol Chilmon ◽  
Wioletta Jackiewicz-Rek
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Fly Ash ◽  
Blast Furnace Slag ◽  
High Performance ◽  
Cement Clinker ◽  
Water Penetration ◽  
Granulated Blast Furnace Slag ◽  
Portland Cement Clinker ◽  
Furnace Slag

The main assumption of eco-efficient High-Performance Concrete (HPC) design is the reduction of Portland cement clinker content without negatively affecting the composite’s mechanical and durability properties. In this paper, three low-clinker HPC mixtures incorporating slag cement (CEM III/B as per EN 197-1) and Supplementary Cementitious Materials (SCMs)—Ground Granulated Blast Furnace Slag (GGBFS), Siliceous Fly Ash (SFA) and Silica Fume (SF)—were designed. The maximum amount of Portland cement clinker from CEM III/B varied from 64 to 116 kg in 1 m3 of concrete mix. The compressive strength of HPC at 2, 7, 14, 28, 56, 90 days, and 2 years after casting, as well as the modulus of elasticity on 2-year-old specimens, was tested. The depth of water penetration under pressure and internal frost resistance in freeze–thaw tests were evaluated after 56 days of curing. Additionally, the concrete pH value tests were performed. The microstructure of 2-year-old HPC specimens was analyzed using Scanning Electron Microscopy (SEM). The research proved that it is possible to obtain low-clinker High-Performance Concretes that reach compressive strength of 76–92 MPa after 28 days of curing, show high values of modulus of elasticity (49–52 GPa) as well as increased resistance to frost and water penetration under pressure.

scholarly journals Preparation of Foamed Phosphogypsum Lightweight Materials by Incorporating Cementitious Additives

2019 ◽  
Vol 25 (3) ◽  
pp. 340-347
Author(s):  
Ting WANG ◽  
Xiaojian GAO ◽  
Jian WANG
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Fly Ash ◽  
Portland Cement ◽  
Blast Furnace Slag ◽  
Building Materials ◽  
Water Resistance ◽  
Hydrated Lime ◽  
Granulated Blast Furnace Slag ◽  
Furnace Slag

As a byproduct of phosphoric acid industry, phosphogypsum has many environmental problems. In order to recycle phosphogypsum to manufacture lightweight building materials, cementitious additives including fly ash, ground granulate blast-furnace slag and Portland cement were added to improve strength and water-resistance and different volume of foam was added to reduce the bulk density. The results show that hydrated lime can improve mechanical strength and water resistance of PG paste and the optimal dosage of hydrated lime is 6 %. Higher addition of fly ash or ground granulated blast-furnace slag improves the fluidity and delays the setting time of PG paste. The addition of 10 ~ 20 % fly ash results in a little reducing influence and 10 % ground granulated blast-furnace slag leads to an increase of 20.7 % for 28 days compressive strength of hardened PG specimen. The higher addition of Portland cement results in the better mechanical strength and water resistance of PG specimens. The 28day compressive and flexural strength reaches 25.9 MPa and 8.9 MPa respectively for the 25 % Portland cement mixture. PG based lightweight building materials can prepared by the addition of 60 % volume of air foam, with compressive strength of 1.7 MPa, bulk density of 521.7 kg/m3 and thermal conductivity of 0.0724 W/(m·K). DOI: http://dx.doi.org/10.5755/j01.ms.25.3.19910

scholarly journals The Compressive Strength and Microstructure of Alkali-Activated Binary Cements Developed by Combining Ceramic Sanitaryware with Fly Ash or Blast Furnace Slag

Minerals ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 337 ◽  
Author(s):  
Juan Cosa ◽  
Lourdes Soriano ◽  
María Borrachero ◽  
Lucía Reig ◽  
Jordi Payá ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Fly Ash ◽  
Blast Furnace Slag ◽  
Calcium Content ◽  
Partial Replacement ◽  
Alkali Activation ◽  
High Calcium ◽  
Furnace Slag ◽  
Alkali Activated

The properties of a binder developed by the alkali-activation of a single waste material can improve when it is blended with different industrial by-products. This research aimed to investigate the influence of blast furnace slag (BFS) and fly ash (FA) (0–50 wt %) on the microstructure and compressive strength of alkali-activated ceramic sanitaryware (CSW). 4 wt % Ca(OH)2 was added to the CSW/FA blended samples and, given the high calcium content of BFS, the influence of BFS was analyzed with and without adding Ca(OH)2. Mortars were used to assess the compressive strength of the blended cements, and their microstructure was investigated in pastes by X-ray diffraction, thermogravimetry, and field emission scanning electron microscopy. All the samples were cured at 20 °C for 28 and 90 days and at 65 °C for 7 days. The results show that the partial replacement of CSW with BFS or FA allowed CSW to be activated at 20 °C. The CSW/BFS systems exhibited better mechanical properties than the CSW/FA blended mortars, so that maximum strength values of 54.3 MPa and 29.4 MPa were obtained in the samples prepared with 50 wt % BFS and FA, respectively, cured at 20 °C for 90 days.

Physico chemical and thermal resistance properties of fly ash/ground granulated blast furnace slag based geopolymer mortar

2021 ◽  
Vol 25 (8) ◽  
pp. 110-120
Author(s):  
M. Sivasakthi ◽  
R. Jeyalakshmi ◽  
N.P. Rajamane ◽  
J. Baskarasundararaj
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Fly Ash ◽  
Blast Furnace Slag ◽  
Elevated Temperatures ◽  
Linear Thermal Expansion ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Granulated Blast Furnace Slag ◽  
Furnace Slag

The present study investigated the physicochemical and thermal properties of fly ash and ground granulated blast furnace slag (GGBS) based geopolymer mortars exposed to elevated temperatures under different reaction conditions. The compressive strength results shows that fly ash based geopolymer mortar exhibits retention of compressive strength up to 800⁰C whereas the addition of GGBS increases the ambient temperature compressive strength, however, thereafter the retention of strength is observed as 66% at 400˚C and 30% at 800˚C. Fourier transform infra-red spectroscopy (FT- IR) and 29Si and 27Al Magic angle spinning nuclear magnetic resonance (MAS-NMR) spectrum confirmed the alumino-silicate network structure of the geopolymer. Thermogravimetry with differential thermal analysis (TGA/DTA) showed that most of the % weight loss occurred in the temperature range between 30-250ºC due to the water loss after that it was stabilized till 1000⁰C. Thermal conductivity has the direct relationship with the temperature whereas it is vice versa for the % linear thermal expansion. The Scanning electron microscopy (SEM) analysis was performed to identify the morphology changes before and after thermal exposure.

scholarly journals Performance of Ground Granulated Blast-Furnace Slag and Coal Fly Ash Ternary Portland Cements Exposed to Natural Carbonation

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3239
Author(s):  
Rosa Abnelia Rivera ◽  
Miguel Ángel Sanjuán ◽  
Domingo Alfonso Martín ◽  
Jorge Luis Costafreda
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Fly Ash ◽  
Blast Furnace Slag ◽  
Coal Fly Ash ◽  
Portland Cements ◽  
Carbonation Process ◽  
Granulated Blast Furnace Slag ◽  
Natural Carbonation ◽  
Furnace Slag

Ternary Portland cements are new cementitious materials that contain different amounts of cement replacements. Ternary Portland cements composed of granulated blast-furnace slag (GBFS), coal fly ash (CFA), and clinker (K) can afford some environmental advantages by lowering the Portland cement clinker use. Accordingly, this is an opportunity to reduce carbon dioxide emissions and achieve net-zero carbon emissions by 2050. Furthermore, GBFS and CFA possess pozzolanic properties and enhance the mechanical strength and durability at later ages. Compressive strength and natural carbonation tests were performed in mortar and concrete. Cement-based materials made with GBFS and/or CFA presented a delay in the compressive strength development. In addition, they exhibited lower carbonation resistance than that of mortar and concrete made with plain Portland cements. Concrete reinforcement remains passive in common conditions; however, it could be corroded if the concrete pore solution pH drops due to the carbonation process. Service life estimation was performed for the ternary cements regarding the carbonation process. This information can be useful to material and civil engineers in designing concretes made with these ternary cements.

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