scholarly journals Influence of Graphene Nanoplatelets on the Compressive and Split Tensile Strengths of Geopolymer Concrete

2021 ◽  
Vol 945 (1) ◽  
pp. 012060
Author(s):  
Fouad Ismail Ismail ◽  
Syed Ahmad Farhan ◽  
Nadzhratul Husna ◽  
Nasir Shafiq ◽  
MohaMohamed Mubarak Abdulmed Wahab ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Fly Ash ◽  
Reference Sample ◽  
Sodium Metasilicate ◽  
Cementitious Materials ◽  
Graphene Nanoplatelets ◽  
Geopolymer Concrete ◽  
Strength Performance ◽  
The Impact

Abstract Geopolymer is now a more advanced alternative to cement and available substitute for OPC while graphene nanoplatelets (GnP) are new nanomaterials with extraordinary properties that can enhance and improve the strength of cementitious materials. Although graphene reinforced concrete has intriguing potential, its implementation in construction requires better knowledge of the impact of GnP on the properties of concrete related to durability. Studies on the compressive and tensile strength performance of geopolymer concrete (GPC) containing GnP are needed. The present study investigated the influence of reinforcing GPC with varying percentages of GnP on the compressive and split tensile strengths of GPC. The addition of GnP ranged from 0.0%, 0.25% and 0.5% by weight of total binder. It has been observed that the addition of GnP increased the compressive strength by 30% and the tensile strength by 22% in comparison to a reference sample with a specified composition of fly ash and sodium metasilicate. In addition, the effect of GnP on enhancing the compressive strength of the geopolymer was shown to diminish as the amount of sodium metasilicate increased.

scholarly journals Influence of Partial Replacement of Micro-Silica by Fly-Ash on Strength Properties of Reactive Powder Concrete

2020 ◽  
Vol 9 (3) ◽  
pp. 2932-2937
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Fly Ash ◽  
Mechanical Performance ◽  
Cementitious Materials ◽  
Partial Replacement ◽  
Reactive Powder Concrete ◽  
Experimental Investigations ◽  
Reactive Powder ◽  
Micro Silica

Reactive powder concrete (RPC) is the ultra-high strength concrete made by cementitious materials like silica fumes, cement etc. The coarse aggregates are completely replaced by quartz sand. Steel fibers which are optional are added to enhance the ductility. Market survey has shown that micro-silica is not so easily available and relatively costly. Therefore an attempt is made to experimentally investigate the reduction of micro-silica content by replacing it with fly-ash and mechanical properties of modified RPC are investigated. Experimental investigations show that compressive strength decreases gradually with addition of the fly ash. With 10 per cent replacement of micro silica, the flexural and tensile strength showed 40 and 46 per cent increase in the respective strength, though the decrease in the compressive strength was observed to be about 20 per cent. For further percentage of replacement, there was substantial drop in compressive, flexural as well as tensile strength. The experimental results thereby indicates that utilisation of fly-ash as a partial replacement to micro silica up to 10 per cent in RPC is feasible and shows quite acceptable mechanical performance with the advantage of utilisation of fly-ash in replacement of micro-silica.

scholarly journals Parametric Strategy for Composite Cement Concrete Blended with Fly Ash & Glass Fiber

2020 ◽  
pp. 162-176
Author(s):  
Madhurima Das ◽  
Siba Prasad Mishra
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Glass Fiber ◽  
Building Materials ◽  
Cement Concrete ◽  
Strength Performance ◽  
X Ray ◽  
Natural Building ◽  
The Impact ◽  
Scanning Electron

Coping with population growth, houses are built to meet the hike. The prerequisites for concrete and steel reinforcements have surged up globally since last 3 to 4decades. Shortage of natural building materials, increased wastes from coal based industries to augment carbon foot print has worried the engineers to reuse their wastes (such as fibres, powders, granules, etc.) as building materials ingredient. Glass fibre has improved flexural capabilities with fly ash dosages in cement concrete and alternately helps in restricting environmental degradation. Present research aims at investigating the impact of glass fiber (at 1%, 2% and 3% addition) and fly ash (dosages of 10% and 20% over the existing fly ash in PPC). The ingredients and microstructure of composites are found by either X-ray fluorescent spectroscopy or scanning electron microscope. Experimental evaluation results of the blended composite concrete parameters of RCC are experimentally evaluated and compared have shown that concrete with 10% cement substitution with fly ash and 3% fibre showed optimum compressive strength performance than the concrete without fibre and fly ash and also chemically resistant against commonly used M-20 grade of Concrete.

scholarly journals Effect of Carboxylic Acid (Benzene Crystallable) in Cement Concrete and Geopolymer Concrete

2020 ◽  
Vol 9 (7) ◽  
pp. 472-475
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Fly Ash ◽  
Carboxylic Acid ◽  
Geopolymer Concrete ◽  
Cement Concrete ◽  
Split Tensile Strength ◽  
Sealing Capacity ◽  
Time Period

The present study appraises the recitals of carboxylic acid- based admixture to increase concrete water tightness and self-sealing capacity of the cement and geopolymer concrete. Outcomes of the previous studies in particular, adding 1% by cement mass of the carboxylic polymer reasons for reduction in the water dispersion under pressure of 7-day wet cured concrete by 50% associated to that of the conforming reference concrete. At 7 days, M4 mix compressive strength is about 43.5% less than M3 mix. The compressive strength of M4 increases and is about 37.6% less than M3 mix at 28 days of curing. At 7 days, M4 mix split tensile strength is about 17.5% less than M3 mix (cement concrete with 0.45 w/c ratio). The split tensile strength of M4 declines and is about 42.3% less than M3 mix at 28 days of curing. The strength of the geopolymer concrete tends to increase as the time period increases due to the presence of fly ash in it. So it is expected that geopolymer concrete will give more strength than cement concrete in long term with the presence of carboxylic acid

scholarly journals Use of waste paper ash or wood ash as substitution to fly ash in production of geopolymer concrete

2021 ◽  
Vol 30 (3) ◽  
pp. 464-476
Author(s):  
Haider Owaid ◽  
Haider Al-Baghdadi ◽  
Muna Al-Rubaye
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Fly Ash ◽  
Flexural Strength ◽  
Sodium Hydroxide ◽  
Wood Ash ◽  
Splitting Tensile Strength ◽  
Waste Paper ◽  
Geopolymer Concrete

Large quantities of paper and wood waste are generated every day, the disposal of these waste products is a problem because it requires huge space for their disposal. The possibility of using these wastes can mitigate the environmental problems related to them. This study presents an investigation on the feasibility of inclusion of waste paper ash (WPA) or wood ash (WA) as replacement materials for fly ash (FA) class F in preparation geopolymer concrete (GC). The developed geopolymer concretes for this study were prepared at replacement ratios of FA by WPA or WA of 25, 50, 75 and 100% in addition to a control mix containing 100% of FA. Sodium hydroxide (NaOH) solutions and sodium silicate (Na2SiO3) are used as alkaline activators with 1M and 10M of sodium hydroxide solution.The geopolymer concretes have been evaluated with respect to the workability, the compressive strength, splitting tensile strength and flexural strength. The results indicated that there were no significant differences in the workability of the control GC mix and the developed GC mixes incorporating WPA or WA. Also, the results showed that, by incorporating of 25–50% PWA or 25% WA, the mechanical properties (compressive strength, splitting tensile strength and flexural strength) of GC mixes slightly decreased. While replacement with 75–100% WPA or with 50–100% WA has reduced these mechanical properties of GC mixes. As a result, there is a feasibility of partial replacement of FA by up to 50% WPA or 25% WA in preparation of the geopolymer concrete.

scholarly journals Strength and abrasion performance of recycled aggregate based geopolymer concrete

2021 ◽  
Author(s):  
Asfaw Mekonnen LAKEW ◽  
Mukhallad M. AL-MASHHADANI ◽  
Orhan CANPOLAT
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Fly Ash ◽  
Coarse Aggregate ◽  
Steel Fiber ◽  
Splitting Tensile Strength ◽  
Partial Replacement ◽  
Geopolymer Concrete ◽  
Recycled Coarse Aggregate ◽  
One Year

This experimental work evaluated geopolymer concrete containing fly ash and slag by partial replacement of natural coarse aggregate (NCA) with recycled coarse aggregate (RCA) to manufacture environmental-friendly concrete. The proportion of recycled aggregates considered consists of 10%, 20%, 30%, and 40% of the total coarse aggregate amount. Also, a steel fiber ratio of 0.3% was utilized. The mechanical properties and abrasion resistance of fly ash/slag-based geopolymer concrete were then assessed. Majorly, the mechanical strength of the concrete samples decreased by the increase of RCA content. The geopolymer concrete with 40% RCA gave 28.3% lesser compressive strength and 24% lower splitting tensile strength than NCA concrete at one year. Also, the flexural strength of concrete specimens was reduced by 35% (from 5.34MPa to 3.5MPa) with the incorporation of 40% RCA. The incorporation of 30% RCA caused 23% and 22.6% reduction in compressive strength at 56 days and one year, respectively. The flexural and splitting tensile strength of the specimens was not significantly reduced (less than 10%) with the inclusion of a recycled coarse aggregate ratio of up to 30%. Furthermore, the abrasion wear thickness of every concrete sample was less than 1mm. RCA inclusion of 20% produced either insignificant reduction or better strength results compared to reference mixtures. As a result, it was considered that the combination of 0.3% steel fiber and 20% recycled coarse aggregate in fly ash/slag-based geopolymer concrete leads to an eco-friendly concrete mix with acceptable short and long-term engineering properties that would lead to sustainability in concrete production and utilization sector.

BLENDED METAKAOLIN AND WASTE CLAY BRICK POWDER AS SOURCE MATERIAL IN SUSTAINABLE GEOPOLYMER CONCRETE

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Mahmood F. Ahmed ◽  
Wasan I. Khalil ◽  
Qais J. Frayyeh
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Global Warming ◽  
Source Material ◽  
Geopolymer Concrete ◽  
Construction Sector ◽  
Clay Brick ◽  
Brick Powder ◽  
The World ◽  
The Impact

Recently, sustainability and ecological related problems have attracted more attention around the world. The construction sector incorporates directly and indirectly in global warming, natural resources depletion, and environmental pollution. This study aims, firstly; to identify the optimum mix of metakaolin (MK) geopolymer concrete required to achieve high compressive strength with respect to the concentration of the alkaline solution and curing system. Secondly, to reduce the impact of brick waste on the environment, by producing geopolymer concrete based on blended MK and waste clay brick powder (WBP). The compressive strength, splitting tensile strength and flexural strength of MK-based geopolymer concrete specimens were studied. Different contents of waste clay brick powder (WBP) (0%, 10%, 15%, and 20%) as a replacement by weight of (MK) were investigated. The results appear that it is possible to produce MK-based geopolymer concrete with a compressive strength of 44.03 MPa, while it was 34.76 MPa at 28 days for specimens with 15% WBP replacement of main source binder. Finally, it could be concluded that green moderate strength geopolymer concrete can be produced and used in different civil engineering applications.

scholarly journals A Comprehensive Study on the Factors Affecting the Workability and Mechanical Properties of Ambient Cured Fly Ash and Slag Based Geopolymer Concrete

2021 ◽  
Vol 11 (18) ◽  
pp. 8722
Author(s):  
Rana Muhammad Waqas ◽  
Faheem Butt ◽  
Xulong Zhu ◽  
Tianshui Jiang ◽  
Rana Faisal Tufail
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Fly Ash ◽  
Geopolymer Concrete ◽  
Factors Affecting ◽  
Naoh Solution ◽  
New Material ◽  
Comprehensive Study ◽  
Slag Content

Geopolymer concrete (GPC), also known as an earth friendly concrete, has been under continuous study due to its environmental benefits and potential as a sustainable alternative to conventional concrete construction. However, there is still a lack of comprehensive studies focusing on the influence of all the design mix variables on the fresh and strength properties of GPC. GPC is still a relatively new material in terms of field application and has yet to secure international acceptance as a construction material. Therefore, it is important that comprehensive studies be carried out to collect more reliable information to expand this relatively new material technology to field and site applications. This research work aims to provide a comprehensive study on the factors affecting the fresh and hardened properties of ambient cured fly ash and slag based geopolymer concrete (FS-GPC). Industrial by-products, fly ash from thermal power plants, and ground granulated blast furnace slag from steel industries were utilized to produce ambient cured FS-GPC. A series of experiments were conducted to study the effect of various parameters, i.e., slag content (10%, 20%, 30%, and 50%), amount of alkaline activator solution (AAS) (35% and 40%), sodium silicate (SS) to sodium hydroxide (SH) ratio (SS/SH = 2.0, 2.5 and 3.0), sodium hydroxide concentration (10 M, 12 M, and 14 M) and addition of extra water on fresh and mechanical properties of FS-GPC. The workability of the fresh FS-GPC mixes was measured by the slump cone test. The mechanical properties of the mixes were evaluated by compressive strength, split tensile strength, flexure strength, and static modulus tests. The results revealed that workability of FS-GPC is greatly reduced by increasing slag content, molarity of NaOH solution, and SS/SH ratio. The compressive strength was improved with an increase in the molarity of NaOH solution and slag content and a decrease in AAS content from 40% to 35%. However, the influence of SS/SH ratio on mechanical properties of FS-GPC has a varying effect. The addition of extra water to enhance the workability of GPC matrix caused a decrease in the compressive strength. The validity of the equations suggested by previous studies to estimate the tensile and flexural strength and elastic modulus of FS-GPC mixes were also evaluated. Based on the test results of this study, empirical equations are proposed to predict the splitting tensile strength, flexural strength, and elastic modulus of ambient cured FS-GPC. The optimal mixtures of FS-GPC in terms of workability and mechanical properties were also proposed for the field applications.

Properties of Fly Ash Based Geopolymer Concrete Exposed to Sustained Elevated Temperatures

2011 ◽  
Vol 250-253 ◽  
pp. 962-968 ◽  
Author(s):  
M.S. Sudarshan ◽  
R.V. Ranganath
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Elevated Temperature ◽  
Fly Ash ◽  
Elevated Temperatures ◽  
Research Work ◽  
Acid Resistance ◽  
Geopolymer Concrete ◽  
Cement Concrete ◽  
Beneficial Effects

Fly ash based geopolymer concrete is gaining importance in the context of developing alternatives to cement concrete. The research work available in the literature shows many beneficial effects of the material in terms of its high early compressive strength, tensile strength, reduced shrinkage, good acid resistance etc., However, there are very few studies carried out on the influence of sustained elevated temperature on the properties of geopolymer concrete. This paper presents the results of some of the properties of fly ash based geopolymer concrete activated using sodium silicate and sodium hydroxide and subjected to elevated temperature at 150°C, 200°C, 300°C, 400ºc under sustained durations of 1 hour, 2 hours and 4 hours. The results show that residual compressive strength is about 20% less than the normal at about 200°C itself possibly due to the development of vapour pressure formed by the non-reactive water present in the system. Beyond 2 hours of sustenance, there is not much of a difference in the properties of concrete.

scholarly journals Effect of Quarry Rock Dust as a Binder on the Properties of Fly Ash and Slag-Based Geopolymer Concrete Exposed to Ambient and Elevated Temperatures

2021 ◽  
Vol 11 (19) ◽  
pp. 9192
Author(s):  
Khadim Hussain ◽  
Faheem Butt ◽  
Mamdooh Alwetaishi ◽  
Rana Muhammad Waqas ◽  
Fahid Aslam ◽  
...  
Keyword(s):  
Weight Loss ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Fly Ash ◽  
Elevated Temperatures ◽  
Geopolymer Concrete ◽  
Residual Compressive Strength ◽  
Hardened Properties ◽  
Mechanical Strengths ◽  
Rock Dust

This study presents the performance of quarry rock dust (QRD) incorporated fly ash (FA) and slag (SG) based geopolymer concretes (QFS-GPC) exposed to ambient and elevated temperatures. A total of five QFS-GPC mix types were prepared. The quantity of FA (50%) was kept constant in all the mixes, and SG was replaced by 5%, 10%, 15%, and 20% of QRD. The fresh, hardened properties of the QFS-GPC mixes, viz., workability, compressive strength, splitting tensile strength, and flexural strengths, and XRD for identification of reaction phases were evaluated. The prepared mixes were also heated up to 800 °C to evaluate the residual compressive strength and weight loss. The workability of the QFS-GPC mixes was observed to be reduced by increasing the dosage (0 to 20%) of QRD. Superplasticizer (SP) was used to maintain the medium standard of workability. The compressive, tensile, and flexural strengths were increased by replacing SG with QRD up to 15%, whereas a further higher dosage (20%) of QRD reduced the mechanical strengths of the QFS-GPC mixes. The strength of the QFS-GPC specimens, heated to elevated temperatures up to 800 °C, was reduced persistently with the increased contents of QRD from 0 to 20%. It was concluded from the study that QFS-GPC can be used to achieve 30 MPa strength of concrete.

scholarly journals Experimental and Statistical Study on Mechanical Characteristics of Geopolymer Concrete

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1651 ◽  
Author(s):  
Yifei Cui ◽  
Kaikai Gao ◽  
Peng Zhang
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Elastic Modulus ◽  
Fly Ash ◽  
Mechanical Characteristics ◽  
Statistical Hypothesis ◽  
Geopolymer Concrete ◽  
Empirical Equations ◽  
Class F Fly Ash ◽  
Class F

This paper studies the statistical correlation in mechanical characteristics of class F fly ash based geopolymer concrete (CFGPC). Experimentally measured values of the compressive strength, elastic modulus and indirect tensile strength of CFGPC specimens made from class F fly ash (CFA) were presented and analyzed. The results were compared with those of corresponding ordinary Portland cement concrete (OPCC) using statistical hypothesis tests. Results illustrated that when possessing similar compressive and tensile strength, the elastic modulus for CFGPC is significantly lower than that of OPCC. The corresponding expressions recommended by standards for the case of OPCC is proved to be inaccurate when applied in the case of CFGPC. Statistical regression was used to identify tendencies and correlations within the mechanical characteristics of CFGPC, as well as the empirical equations for predicting tensile strength and elastic modulus of CFGPC from its compressive strength values. In conclusion, CFGPC and OPCC has significant differences in terms of the correlations between mechanical properties. The empirical equations obtained in this study could provide relatively accurate predictions on the mechanical behavior of CFGPC.

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