Use of OPC to improve setting and early strength properties of low calcium fly ash geopolymer concrete cured at room temperature

2015 ◽  
Vol 55 ◽  
pp. 205-214 ◽  
Author(s):  
Pradip Nath ◽  
Prabir Kumar Sarker
Keyword(s):  
Fly Ash ◽  
Room Temperature ◽  
Strength Properties ◽  
Geopolymer Concrete ◽  
Low Calcium ◽  
Early Strength

scholarly journals Practical Prediction Models of Tensile Strength and Reinforcement-Concrete Bond Strength of Low-Calcium Fly Ash Geopolymer Concrete

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 875
Author(s):  
Chenchen Luan ◽  
Qingyuan Wang ◽  
Fuhua Yang ◽  
Kuanyu Zhang ◽  
Nodir Utashev ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Fly Ash ◽  
Bond Strength ◽  
Prediction Models ◽  
Splitting Tensile Strength ◽  
Geopolymer Concrete ◽  
Structural Factors ◽  
Test Results ◽  
Portland Cement Concrete ◽  
Low Calcium

There have been a few attempts to develop prediction models of splitting tensile strength and reinforcement-concrete bond strength of FAGC (low-calcium fly ash geopolymer concrete), however, no model can be used as a design equation. Therefore, this paper aimed to provide practical prediction models. Using 115 test results for splitting tensile strength and 147 test results for bond strength from experiments and previous literature, considering the effect of size and shape on strength and structural factors on bond strength, this paper developed and verified updated prediction models and the 90% prediction intervals by regression analysis. The models can be used as design equations and applied for estimating the cracking behaviors and calculating the design anchorage length of reinforced FAGC beams. The strength models of PCC (Portland cement concrete) overestimate the splitting tensile strength and reinforcement-concrete bond strength of FAGC, so PCC’s models are not recommended as the design equations.

scholarly journals Alkali-Silica Reaction Resistance and Pore Solution Composition of Low-Calcium Fly Ash-Based Geopolymer Concrete

2020 ◽  
Vol 5 (11) ◽  
pp. 96
Author(s):  
Jiawei Lei ◽  
Jiajun Fu ◽  
En-Hua Yang
Keyword(s):  
Fly Ash ◽  
Pore Solution ◽  
Systematic Investigation ◽  
Alkali Silica Reaction ◽  
Geopolymer Concrete ◽  
Portland Cement Concrete ◽  
Solution Composition ◽  
Low Calcium ◽  
Underlying Mechanisms ◽  
One Year

Low-calcium fly ash-based geopolymer concrete is generally reported to be less vulnerable to alkali-silica reaction (ASR) than conventional ordinary Portland cement concrete. However, the lack of understanding of pore solution composition of the low-calcium fly ash-based geopolymer limits the investigation of the underlying mechanisms for the low ASR-induced expansion in the geopolymer concrete. This study presents a systematic investigation of the pore solution composition of a low-calcium fly ash-based geopolymer over a period of one year. The results show that the pore solution of the fly ash geopolymer is mainly composed of alkali ions, silicates, and aluminosilicates species. The lower expansion of the geopolymer concrete in the current study is most probably due to the insufficient alkalinity in the geopolymer pore solution as the hydroxide ions are largely consumed for the fly ash dissolution.

MECHANICAL AND DURABILITY CHARACTERISTICS OF GGBS DOLOMITE GEOPOLYMER CONCRETE

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Aikot Pallikkara Shashikala ◽  
Praveen Nagarajan ◽  
Saranya Parathi
Keyword(s):  
Fly Ash ◽  
Silica Fume ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Setting Time ◽  
Cementitious Materials ◽  
Strength Properties ◽  
Industrial Wastes ◽  
Geopolymer Concrete ◽  
By Products

Production of Portland cement causes global warming due to the emission of greenhouse gases to the environment. The need for reducing the amount of cement is necessary from sustainability point of view. Alkali activated and geopolymeric binders are used as alternative to cement. Industrial by-products such as fly ash, ground granulated blast furnace slag (GGBS), silica fume, rice husk ash etc. are commonly used for the production of geopolymer concrete. This paper focuses on the development of geopolymer concrete from slag (100% GGBS). Effect of different cementitious materials such as lime, fly ash, metakaolin, rice husk ash, silica fume and dolomite on strength properties of slag (GGBS) based geopolymer concrete are also discussed. It is observed that the addition of dolomite (by-products from rock crushing plants) into slag based geopolymer concrete reduces the setting time, enhances durability and improves rapidly the early age strength of geopolymer concrete. Development of geopolymer concrete with industrial by-products is a solution to the disposal of the industrial wastes. The quick setting concrete thus produced can reduce the cost of construction making it sustainable also.

Fly Ash Based Lightweight Geopolymer Concrete Using Foaming Agent Technology

2014 ◽  
Vol 679 ◽  
pp. 20-24 ◽  
Author(s):  
Mohd Mustafa Al Bakri Abdullah ◽  
Zarina Yahya ◽  
Muhammad Faheem Mohd Tahir ◽  
Kamarudin Hussin ◽  
Mohammed Binhussain ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Room Temperature ◽  
Lightweight Concrete ◽  
Agent Technology ◽  
Alkali Activation ◽  
Geopolymer Concrete ◽  
Foaming Agent ◽  
Curing Conditions ◽  
Foam Generator

This paper presents the mechanical properties of a lightweight geopolymer concrete synthesized by the alkali-activation of a fly ash source (FA) produced by mixing a paste of geopolymer with foam produced by using NCT Foam Generator. Two curing conditions are used, curing at room temperature and curing in an oven with a constant temperature which is 60 oC. Bulk density showed that fly ash-based geopolymer lightweight concrete is light with the density of 1225 kg/m3 - 1667 kg/m3 with an acceptable compressive strength of 17.60 MPa for the density of 1667 kg/m3.

scholarly journals Studies on effect of sugarcane bagasse fibre on mechanical properties and workability of low calcium fly ash and slag based geopolymer concrete

2021 ◽  
Vol 309 ◽  
pp. 01112
Author(s):  
T. Srinivas ◽  
Srimanthula Chandana ◽  
N V Ramana Rao
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Sugarcane Bagasse ◽  
Rest Period ◽  
Geopolymer Concrete ◽  
Inorganic Polymers ◽  
Low Calcium ◽  
Hardened Properties ◽  
Bagasse Fibre

Individuals from the group of inorganic polymers are known as geopolymers. The geopolymer material's compound organisation is similar to that of typical zeolitic materials, however the microstructure is undefined rather than translucent. The polymerisation interaction includes a considerably quick substance response under antacid condition on Si-Al minerals and that meets the basic properties of concrete as well as falls under classification of manageability. Utilization of various fibres like steel, glass, sugarcane bagasse etc, significantly influences fresh and hardened properties of concrete. Sugarcane bagasse fibre is a by-product from sugar industries and can be used as a fibre in concrete. The target of this paper is to study an effect of sugarcane bagasse fibre on mechanical properties such as compressive, tensile and flexural sgength and also the workability of low calcium fly ash (Class-F) and slag based geopolymer concrete of G40 grade which is équivalent to M40.. Sugarcane baggase ash fibre has been used for both the concencrte G40 and M40 as 0.5%,1%,1.5%,2%. All the samples were casted and oven cured at 60o for 24 hours after one day rest period and remaining days cured in an ambient temperature, then tested on 3rd, 7th and 28th day to assess the mechanical properties, such as Compressive, Tensile, and Flexure strength. The results were compared among controlled concrete (CC), controlled concrete with sugarcane bagasse fibre (CCF), geopolymer concrete (GPC) and geopolymer concrete with sugarcane bagasse fibre (GPCF). The results revealed that with addition of SCBF, the mechanical properties have been enhanced significantly.

scholarly journals Mechanical and Microstructural Characterization of Quarry Rock Dust Incorporated Steel Fiber Reinforced Geopolymer Concrete and Residual Properties after Exposure to Elevated Temperatures

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6890
Author(s):  
Muhammad Ibraheem ◽  
Faheem Butt ◽  
Rana Muhammad Waqas ◽  
Khadim Hussain ◽  
Rana Faisal Tufail ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Weight Loss ◽  
Compressive Strength ◽  
Fly Ash ◽  
Mechanical Strength ◽  
Elevated Temperatures ◽  
Strength Properties ◽  
Steel Fibers ◽  
Geopolymer Concrete

The purpose of this research is to study the effects of quarry rock dust (QRD) and steel fibers (SF) inclusion on the fresh, mechanical, and microstructural properties of fly ash (FA) and ground granulated blast furnace slag (SG)-based geopolymer concrete (GPC) exposed to elevated temperatures. Such types of ternary mixes were prepared by blending waste materials from different industries, including QRD, SG, and FA, with alkaline activator solutions. The multiphysical models show that the inclusion of steel fibers and binders can enhance the mechanical properties of GPC. In this study, a total of 18 different mix proportions were designed with different proportions of QRD (0%, 5%, 10%, 15%, and 20%) and steel fibers (0.75% and 1.5%). The slag was replaced by different proportions of QRD in fly ash, and SG-based GPC mixes to study the effect of QRD incorporation. The mechanical properties of specimens, i.e., compressive strength, splitting tensile strength, and flexural strength, were determined by testing cubes, cylinders, and prisms, respectively, at different ages (7, 28, and 56 days). The specimens were also heated up to 800 °C to evaluate the resistance of specimens to elevated temperature in terms of residual compressive strength and weight loss. The test results showed that the mechanical strength of GPC mixes (without steel fibers) increased by 6–11%, with an increase in QRD content up to 15% at the age of 28 days. In contrast, more than 15% of QRD contents resulted in decreasing the mechanical strength properties. Incorporating steel fibers in a fraction of 0.75% by volume increased the compressive, tensile, and flexural strength of GPC mixes by 15%, 23%, and 34%, respectively. However, further addition of steel fibers at 1.5% by volume lowered the mechanical strength properties. The optimal mixture of QRD incorporated FA-SG-based GPC (QFS-GPC) was observed with 15% QRD and 0.75% steel fibers contents considering the performance in workability and mechanical properties. The results also showed that under elevated temperatures up to 800 °C, the weight loss of QFS-GPC specimens persistently increased with a consistent decrease in the residual compressive strength for increasing QRD content and temperature. Furthermore, the microstructure characterization of QRD blended GPC mixes were also carried out by performing scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy dispersive spectroscopy (EDS).

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