Effect of curing on mechanical strength and microstructure of fly ash blend GGBS geopolymer, Portland cement mortar and its behavior at elevated temperature

2021 ◽  
Author(s):  
N Poornima ◽  
Dheeraj katyal ◽  
T Revathi ◽  
M Sivasakthi ◽  
R Jeyalakshmi
Keyword(s):  
Elevated Temperature ◽  
Fly Ash ◽  
Portland Cement ◽  
Mechanical Strength ◽  
Cement Mortar

scholarly journals Strength Development and Elemental Distribution of Dolomite/Fly Ash Geopolymer Composite under Elevated Temperature

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 1015 ◽  
Author(s):  
Emy Aizat Azimi ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Petrica Vizureanu ◽  
Mohd Arif Anuar Mohd Salleh ◽  
Andrei Victor Sandu ◽  
...  
Keyword(s):  
Elevated Temperature ◽  
Fly Ash ◽  
Portland Cement ◽  
Ordinary Portland Cement ◽  
Raw Materials ◽  
Liquid Sodium ◽  
Strength Development ◽  
Elemental Distribution ◽  
Distribution Analysis ◽  
Geopolymer Composites

A geopolymer has been reckoned as a rising technology with huge potential for application across the globe. Dolomite refers to a material that can be used raw in producing geopolymers. Nevertheless, dolomite has slow strength development due to its low reactivity as a geopolymer. In this study, dolomite/fly ash (DFA) geopolymer composites were produced with dolomite, fly ash, sodium hydroxide, and liquid sodium silicate. A compression test was carried out on DFA geopolymers to determine the strength of the composite, while a synchrotron Micro-Xray Fluorescence (Micro-XRF) test was performed to assess the elemental distribution in the geopolymer composite. The temperature applied in this study generated promising properties of DFA geopolymers, especially in strength, which displayed increments up to 74.48 MPa as the optimum value. Heat seemed to enhance the strength development of DFA geopolymer composites. The elemental distribution analysis revealed exceptional outcomes for the composites, particularly exposure up to 400 °C, which signified the homogeneity of the DFA composites. Temperatures exceeding 400 °C accelerated the strength development, thus increasing the strength of the DFA composites. This appears to be unique because the strength of ordinary Portland Cement (OPC) and other geopolymers composed of other raw materials is typically either maintained or decreases due to increased heat.

scholarly journals Effect of Elevated Temperature on Alkali Activated Slag and Fly Ash based Geopolymer Concrete

2020 ◽  
Vol 9 (4) ◽  
pp. 1241-1250
Keyword(s):  
Compressive Strength ◽  
Elevated Temperature ◽  
Fly Ash ◽  
Flexural Strength ◽  
Portland Cement ◽  
Ordinary Portland Cement ◽  
Geopolymer Concrete ◽  
Base Materials ◽  
Activated Slag ◽  
Alkali Activated

Activated Slag (AAS) and Fly Ash (FA) based geopolymer concrete a new blended alkali-activated concrete that has been progressively studied over the past years because of its environmental benefits superior engineering properties. Geopolymer has many favorable characteristics in comparison to Ordinary Portland Cement. Many base materials could be utilized to make geopolymer with the convenient concentration of activator solution. In this study, the experimental program composed of two phases; phase on divided into four groups; Group one deliberated the effect of sodium hydroxide molarity and different curing condition on compressive strength. Group two studied the effect of alkali activated solution (NaOH and Na2SiO3) content on compressive strength and workability. The effect of sand replacement with slag on compressive strength and workability was explained in group three. Group four studied the effect of slag replacement with several base materials Fly Ash (FA), Ordinary Portland Cement (OPC), pulverized Red Brick (PRB), and Meta Kaolin (MK). Phase two contains three mixtures from phase one which had the highest compressive strength. For each mixture, the fresh concrete test was air content. In addition the hardened concrete tests were the compressive strength at 3, 7, 28, 90, 180, and 365 days, the flexural strength at 28, 90, and 365 days, and the young's modulus at 28, 90, and 365 days. Moreover; the three mixtures were exposed to elevated temperature at 100oC, 300oC, and 600oC to study the effect of elevated temperature on compressive and flexural strength.

scholarly journals The effect of ashes on the properties of cement mortar and typical concrete fillers

2019 ◽  
Author(s):  
Janina Setina ◽  
Inna Juhnevica ◽  
Janis Baronins
Keyword(s):  
Portland Cement ◽  
Mechanical Strength ◽  
Frost Resistance ◽  
Building Materials ◽  
Cement Mortar ◽  
Hardened Concrete ◽  
Short Term ◽  
Lightweight Structures ◽  
Active Additive

The production of heat and electricity from shale and biomass is leading to a significant increase in the amount of the combustion residues i.e. ashes. The utilization of ashes as the pozzolanic additive in the production of Portland cement mortar and concrete for the construction of lightweight structures is the most popular way. The interaction of ashes with other typical concrete fillers also can affect the final relative short-term and long-term properties of fresh and hardened concrete when designing the concrete mixture. The influence of wood and shale ashes on the properties of cement mortar and typical concrete fillers (sand, limestone, dolomite) – fresh mortar, hydration process, and hardened mortar were researched and assessed for their applicability in the production of concrete. The best results of mechanical strength, frost resistance and water absorption were measured in case of shale ashes containing samples in combination with cement and selected concrete additive – sand. Shale ashes can be recommended for application as the active additive. Since wood ash was exhibiting lower activity, it can also be applied as a filler to produce building materials.

Long term mechanical strength behaviour in fly ash/Portland cement mortars prepared using processed ashes

2002 ◽  
Vol 77 (3) ◽  
pp. 336-344 ◽  
Author(s):  
J Payá ◽  
M V Borrachero ◽  
J Monzó ◽  
E Peris-Mora ◽  
M Bonilla
Keyword(s):  
Fly Ash ◽  
Portland Cement ◽  
Mechanical Strength ◽  
Cement Mortars

scholarly journals Influences of Waste Concrete Powder on the Strength Development and Hydration Products of Mortar Containing Fly Ash

2021 ◽  
Author(s):  
Huashan YANG ◽  
Yujun CHE
Keyword(s):  
Fly Ash ◽  
Portland Cement ◽  
Cement Mortar ◽  
Setting Time ◽  
Flow Index ◽  
Strength Development ◽  
Test Results ◽  
Hydration Products ◽  
Waste Concrete ◽  
Time Flow

During recycling waste concrete, a large amount of waste concrete powder (WCP) is generated. However, efficient utilization of WCP remains an unresolved issue. This paper investigates the influences of WCP on the properties and hydration products of cement mortar containing fly ash (FA). This study used two different types of WCPs. One was made from an ordinary Portland cement mortar, and the other was derived from a Portland cement mortar. WCP replaced 10%, 20%, and 30% of FA. The water requirement, setting time, flow index, strength, hydration products, and microstructure of FA mortar incorporating WCP were investigated. Test results indicate that the WCP has no significant influence on the performances and hydration products of FA mortar. By adequately combining WCP and FA, the FA mortar with required performances could be reached.

scholarly journals Effect of Bogue Potential Phases of Clinker on the Mechanical Strength of Fly ash-Limestone Based Portland Composite Cement

2021 ◽  
Vol 2 (2) ◽  
pp. 1-6
Author(s):  
B N Mohapatra
Keyword(s):  
Fly Ash ◽  
Portland Cement ◽  
Natural Resources ◽  
Mechanical Strength ◽  
Cementitious Materials ◽  
Strength Development ◽  
Blended Cements ◽  
Current Production ◽  
Increasing Demand

Continuous rise in population coupled with infrastructural requirements leads to increasing demand of cement which is projected to be around 4.8 billion tons by 2030 and 6.0 billion tons annually by 2050 from current production level of more than 4.2 billion tons [1], and this further requires judicious use of natural resources, particularly limestone on one side and to mitigate carbon and energy footprints on other for sustainable development. Therefore, to bring down environmental impact during cement production, cement industries have been engaged over the years to substitute Portland cement with alternative cementitious materials; fly ash, granulated blast furnace slag, limestone etc individually or in combination of two-three mineral constituents in the manufacture of blended cements, which showed better durability characteristics in comparison to ordinary Portland cement. The formulation and commercialisation of these cements largely depends on the quality of Portland clinkers in terms of oxide constituents, potential as well as actual phase composition, morphology and granulometry of alite and belite grains, along with availability and quality of the cementing materials, prevalent standard norms and regulations. In view of above, present paper highlights the effect of different clinkers in terms of potential minerals as per Bogue calculations (CL-1:C3S-48.20%, C3A-6.30%; CL-2:C3S-54.20%, C3A-9.30% and CL-3: C3S-60.05%, C3A-9.0%) on mechanical strength of fly ash-limestone based ternary cement blends, Portland composite cements, similar to CEM-II/A, B-M as per EN-197-1, prepared with 15, 20, 25, 30 and 35% by weight fly ash and 5 & 10% by weight limestone, by inter-grinding of all cement constituents process, maintaining Blaine’s fineness at 370±10m2/kg, and the results of compressive strength at different curing ages showed optimum strength development in case of clinker CL-2 with potential phases, C3S-54.20% and C3A-9.30%, thus leading to better management of natural resources and extended mine life.

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