scholarly journals Effect of Fine Aggregate Particle Characteristics on Mechanical Properties of Fly Ash-Based Geopolymer Mortar

Minerals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 897
Author(s):  
Heng Li ◽  
Pengpeng Gao ◽  
Fang Xu ◽  
Tao Sun ◽  
Yu Zhou ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Pass Rate ◽  
Fine Aggregate ◽  
X Ray Diffraction ◽  
River Sand ◽  
Fine Aggregates ◽  
Compressive And Flexural Strengths ◽  
Filling Coefficient ◽  
Fineness Modulus

This research aimed to investigate the effect of fine aggregate particles on mechanical properties of fly ash-based geopolymer mortar. In this work, seven kinds of river sand particles were designed based on different fine aggregate characteristics. The fineness modulus was adopted to quantitatively describe the gradation of sands. The fluidity, compressive, flexural, and tensile strengths of geopolymer mortar with different sand gradations were analyzed by laboratory tests. Furthermore, the composition and morphology of fly ash-based geopolymer mortar was analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The reasonable gradation range and filling effect of sand were obtained. The results show that fluidity and compressive and flexural strengths of geopolymer mortar both improve with the increase of the fineness modulus, while specific surface area and voidage are opposite. The tensile strength of mortar largely lies on the interface properties between the geopolymer binder and fine aggregates. When the pass rate of the key sieving size 1.18 mm is 75–95%, the pass rate of the key sieving size 0.15 mm is 15–25%, the fineness modulus is 2.2–2.6 and the appropriate filling coefficient of geopolymer paste is around 1.0–1.15, the comprehensive performance of geopolymer mortar is the best. This research paper could provide a basis for the design of geopolymer mortar based on fly ash, and it is of great significance for its popularization and application.

scholarly journals Influence of Fly Ash on Mechanical Properties and Hydration of Calcium Sulfoaluminate-Activated Supersulfated Cement

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2514
Author(s):  
Zhengning Sun ◽  
Jian Zhou ◽  
Qiulin Qi ◽  
Hui Li ◽  
Na Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Flexural Strength ◽  
Heat Evolution ◽  
Hydration Products ◽  
X Ray Diffraction ◽  
Calcium Sulfoaluminate Cement ◽  
Calcium Sulfoaluminate ◽  
Granulated Blast Furnace Slag ◽  
Compressive And Flexural Strengths

This paper aimed to report the effects of fly ash (FA) on the mechanical properties and hydration of calcium sulfoaluminate-activated supersulfated cement (CSA-SSC). The CSA-SSC comprises of 80% granulated blast furnace slag (GBFS), 15% anhydrite, and 5% high-belite calcium sulfoaluminate cement (HB-CSA) clinker. The hydration products of CSA-SSC with or without FA were investigated by X-ray diffraction and thermogravimetric analysis. The experimental results indicated that the addition of FA by 10% to 30% resulted in a decrease in the rate of heat evolution and total heat evolution of CSA-SSC. As the content of FA was increased in the CSA-SSC system, the compressive and flexural strengths of the CSA-SSC with FA after 1 day of hydration were decreased. After 7 days of hydration, the compressive and flexural strength of CSA-SSC mixed with 10 wt.% and 20 wt.% of FA rapidly increased and exceeded that of ordinary Portland cement (OPC), especially the flexural strength. Moreover, the compressive strength of CSA-SSC mixed with 30 wt.% of FA after 90 days of hydration was close to that of OPC, and flexural strength of CSA-SSC mixed with 30 wt.% of FA after 7 days of hydration was close to that of OPC. The hydration products of the CSA-SSC and CSA-SSC mixed with FA were mainly ettringite and calcium silicate hydrate (C-S-H).

scholarly journals GGBS based alkali activated fine aggregate in concrete - Properties at fresh and hardened state

2021 ◽  
Vol 13 (1) ◽  
pp. 47-53
Author(s):  
G. Lizia Thankam ◽  
T.R. Neelakantan ◽  
S. Christopher Gnanaraj
Keyword(s):  
Mechanical Properties ◽  
Alkaline Solution ◽  
Elevated Temperatures ◽  
Fresh Concrete ◽  
Hardened Concrete ◽  
Fine Aggregate ◽  
River Sand ◽  
Complete Replacement ◽  
Concrete Properties ◽  
Fine Aggregates

Abstract Scarcity of the construction materials, peculiarly the natural river sand has become a serious threat in the construction industry. Though many researchers of developed and developing countries are trying to find alternative sources for the same, the complete replacement of the fine aggregate in concrete is crucial. Geopolymer sand developed from the Industrial waste (Ground granulated blast furnace slag - GGBS) is an effective alternative for the complete replacement of the natural sand. The GGBS based geopolymer sand (G-GFA) was tested for physical and chemical properties. Upon the successful achievement of the properties in par with the natural river sand, the fresh properties (fresh concrete density & slump) and hardened properties (compressive strength, tensile strength & flexural strength) of the concrete specimens developed with G-GFA were studied. The G-GFA is obtained by both air drying (AD-G-GFA) and oven drying (OD-F-GFA) after the dry mixing of the alkaline solution and GGBS for about 10 min. Thus, developed fine aggregates were studied separately for the fresh and hardened concrete to optimize the feasible one. Superplasticizer of 0.4% is included in the concrete mix to compensate the sightly hydrophilic nature of the fine aggregates produced. The mechanical properties of the concrete with G-GFA are observed to be more than 90% close to that of the concrete developed with natural river sand. Thus, both the fresh and mechanical properties of the G-GFA concrete specimens resulted in findings similar to those of the control specimen developed with natural river sand reflecting the plausibility of G-GFA as a complete replacement choice to the fine aggregate in the concrete industry. The flaky GGBS particles merge well with the alkaline solution at room temperature itself since the former gets dried at elevated temperatures. Thus, more feasible fresh concrete properties and mechanical properties were recorded for the AD-G-GFA than the OD-G-GFA.

scholarly journals Studies on manufactured sand effect on mechanical properties of geopolymer concrete as replacement of river sand in fine aggregate

2021 ◽  
Vol 309 ◽  
pp. 01114
Author(s):  
K. Veera Babu ◽  
T. Srinivas ◽  
Mahathi Tummala
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Construction Material ◽  
Environmental Concerns ◽  
Fine Aggregate ◽  
Geopolymer Concrete ◽  
River Sand ◽  
Natural Sand ◽  
Manufactured Sand ◽  
Low Calcium

Concrete is the most adaptable, long-lasting, and dependable construction material on the planet. There are numerous environmental concerns associated with the production of OPC, and natural sand is becoming more expensive and scarce as a result of unlawful river sand dredging. The greatest replacement material for traditional concrete is geopolymer concrete with low calcium fly ash. The purpose of this paper is to investigate the mechanical properties of geopolymer concrete of grades G30 and G50, which are equivalent to M30 and M50, when river sand is substituted in various quantities with manufactured sand, such as 0%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, and 100%. When compared to the equivalent grades of controlled concrete, geopolymer concrete improves mechanical properties such as compressive, tensile, and flexural strengths.

scholarly journals Effect on the properties of fresh and hardened concrete made using fly ash geopolymer sand

2021 ◽  
Author(s):  
G. Lizia Thankam ◽  
T.R. Neelakantan ◽  
S. Christopher Gnanaraj
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Laboratory Tests ◽  
Water Adsorption ◽  
Fresh Concrete ◽  
Hardened Concrete ◽  
Fine Aggregate ◽  
Curing Process ◽  
River Sand ◽  
Curing Method

AbstractFly ash-based geopolymer fine aggregate is a potential replacement material for the natural river sand as it has similar physicochemical properties. This paper reports the experimental investigation of a study conducted using this fine aggregate in concrete with a focus on the properties of fresh and hardened concrete. The geopolymer fine aggregate was developed by air curing process and oven curing method. The oven curing method yielded relatively better mechanical properties in concrete specimens. The oven curing results in better behavior at later age also. Laboratory tests were conducted to ascertain the fresh concrete density, slump value, hardened concrete density, compressive strength, tensile strength, and flexural strength of the concrete specimens. The microstructure of the concrete specimens was analyzed using scanning electron microscope which indicated the agglomeration of the fly ash particles with few voids demonstrating the higher water adsorption capacity of the same. The unreacted particles noted in the microstructure later tend to merge with the lime obtained from the hydration of cement so as to develop improved later age mechanical strength. The results on mechanical properties of the concrete indicate much similar results to that of the concrete developed with the normal river sand, which confirms that the geopolymer sand is an ideal replacement choice for natural river sand.

Effects of Rubber Particles on Rheological and Mechanical Properties of Concrete Containing CaCO3 Nanoparticles

2018 ◽  
Vol 926 ◽  
pp. 109-114
Author(s):  
Li Wang ◽  
Ben Dong Zhao
Keyword(s):  
Mechanical Properties ◽  
Fine Aggregate ◽  
Rubberized Concrete ◽  
Cement Pastes ◽  
Effective Strategies ◽  
Waste Rubber ◽  
Fine Aggregates ◽  
Strength Tests ◽  
Rubber Particles ◽  
Compressive And Flexural Strengths

Lots of waste rubber is being produced in the world and the utilization of it not only mitigate environmental impacts caused by waste rubber disposal but also enhance sustainable development. As a result, rubberized concrete, by incorporation of waste rubber into concrete, should be considered as one of the effective strategies to take advantage of waste rubber. However, problems such as low strengths, weak adhesion between rubber particles and cement pastes, and undesirable pore structures associated with rubberized concrete should be pay more attention to. In this study, the effect of replacement fine aggregate with rubber particles on rheological and mechanical properties of concrete containing CaCO3 nanoparticles was examined through slump, compressive and flexural strength tests. Rubber particles were employed to replace the fine aggregate equally by volume while CaCO3 nanoparticles were used as an equal part of binder by weight. Different sizes and volume contents of rubber particles were evaluated as well as different weight contents of CaCO3 nanoparticles. In addition, corresponding tests were also performed to evaluate the effect of CaCO3 nanoparticles in comparison to concrete specimens without CaCO3 nanoparticles. The results showed that replacement fine aggregates with rubber particles had some influence on the mechanical properties of rubberized concrete, resulting in undesirable findings in terms of compressive and flexural strengths. However, the incorporation of CaCO3 nanoparticles improved mechanical properties of rubberized concrete. Regarding slump test, the rubberized concrete without CaCO3 nanoparticles showed better performance. Considering rheological and mechanical properties, rubberized concrete with 1% CaCO3 nanoparticles presented acceptable results.

scholarly journals Evaluation of the Performance and Microstructure of Ecofriendly Construction Bricks Made with Fly Ash and Residual Rice Husk Ash

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Chao-Lung Hwang ◽  
Trong-Phuoc Huynh
Keyword(s):  
Fly Ash ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Microstructural Characterization ◽  
Fine Aggregate ◽  
Potential Candidate ◽  
X Ray Diffraction ◽  
Steel Mold ◽  
Fine Aggregates ◽  
Class F Fly Ash

This research presents the engineering performance and the microstructural characterization of ecofriendly construction bricks that were produced using a binder material made from a mixture of class-F fly ash (FA) and residual rice husk ash (RHA). Unground rice husk ash (URHA) was used as a partial fine aggregate substitute (0–40%). The solid bricks of 220 × 105 × 60 mm in size were prepared by mixing FA and RHA with an alkaline solution and fine aggregates, formed by compressing the mixture in a steel mold under 35 MPa of forming pressure, and then cured at 35°C and 50% relative humidity until the required testing ages. The tests of compressive strength, water absorption, and bulk density were conducted in accordance with relevant Vietnamese standards in order to estimate the effect of the URHA content on the engineering performance of the hardened bricks. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) were performed to determine the microstructure and the phase composition of the brick samples. The results show that properties of these bricks conformed to relevant Vietnamese standards. Therefore, FA and RHA are potential candidate materials for producing ecofriendly construction bricks using geopolymerization technology.

scholarly journals Flexural Fatigue performance of Alkali Activated Slag Concrete mixes incorporating Copper Slag as Fine Aggregate

2015 ◽  
Vol 10 (1) ◽  
pp. 7-18 ◽  
Author(s):  
B.M. Mithun ◽  
M.C. Narasimhan ◽  
Palankar Nitendra ◽  
A.U. Ravishankar
Keyword(s):  
Mechanical Properties ◽  
Plain Concrete ◽  
Copper Slag ◽  
Fatigue Performance ◽  
Fine Aggregate ◽  
River Sand ◽  
Alkali Activated Slag ◽  
Fine Aggregates ◽  
Activated Slag ◽  
Alkali Activated

Abstract The present investigation attempts a detailed study of mechanical properties and fatigue characteristics of a new class of Alkali Activated Slag Concrete (AASC) mixes incorporating Copper Slag (CS) as fine aggregates. The natural river sand is replaced with Copper Slag, upto 100% (by volume) as fine aggregate in these AASC mixes. The behavior of plain concrete prisms, cast with this range of AASC mixes under dynamic cyclic loads with sand/CS fine aggregates is studied and is compared with conventional OPC-based concrete specimens. The results indicate that incorporation of CS even upto 100% as fine aggregates, did not have any adverse effects on the mechanical properties of AASC mixes. The AASC mixes with CS displayed slightly better fatigue performance as compared to AASC mix with river sand. An attempt is also made herein to statistically describe the fatigue life data of AASC mixes using a 2-parameter Weibull distribution.

scholarly journals Synthesis and Characterization of Synthetic Sand by Geopolymerization of Industrial Wastes (Fly ash& GGBS) Replacing the Natural River Sand

2021 ◽  
Author(s):  
Lizia Thankam Gnanadurai ◽  
Neelakantan Thruvas Renganathan ◽  
Christopher Gnanaraj Selvaraj
Keyword(s):  
Fly Ash ◽  
Xrd Analysis ◽  
Optical Microscope ◽  
Industrial Wastes ◽  
Fine Aggregate ◽  
River Sand ◽  
Natural Sand ◽  
Aquatic Life ◽  
Mountain Ranges ◽  
Fine Aggregates

Abstract The diminution of the natural sources in the form of dredging the riverbanks and blasting the mountain ranges has always dented the balance of the eco system which in turn results in disasters as well at times. This alarming situation accelerates the global warming, threatens the biota life in riverbanks, diminishes the ground water level, harms the aquatic life and affects the growth of agriculture. This study is an attempt to synthesis fine aggregates from the industrial byproducts such as fly ash and GGBS through the process of geopolymerization which enables the formation of aluminosilicate networks upon the addition of the alkaline activator solution (Na 2 SiO 3 + NaOH) into the byproducts which is then allowed for oven drying as well as air drying to accelerate the process. The Fly ash geopolymerized fine aggregate(F-GFA) and the GGBS geopolymerized fine aggregate(G-GFA) were noted to exhibit adequate physiochemical and mechanical properties in par with the natural sand. The production of GFA is considered as eco friendly process since it ceases the extensive usage of river sand and incorporates the effective usage of Industrial by products (Fly ash and GGBS) thereby minimizing the land pollution and its consequent harmful hazards. Though the F-GFA and G-GFA showcased higher water absorption ratio than the natural sand, owing to the unreacted fly ash and GGBS particles. Nevertheless, the same initiated the adequate compressive strength attainment up to 90% of natural sand, by reacting with the lime expelled out of the hydration process of cement in the mortar specimens developed in this experimental study. The microstructure of the samples was further examined through Optical microscope, Scanning Electron microscope (SEM) and X-Ray Diffraction (XRD) analysis in order to corroborate the experimental results of this study. The results thus obtained, strongly recommend the potential of the F-GFA and G-GFA as an ideal replacement material for natural sand.

scholarly journals Enhancement of the Ductility Index of Concrete Pavement Using Moderate-Volume of Hybrid Fibers

2018 ◽  
Vol 7 (4.20) ◽  
pp. 103
Author(s):  
Qais Sahib Banyhussan
Keyword(s):  
Fly Ash ◽  
Aggregate Size ◽  
Plain Concrete ◽  
Stress Index ◽  
Maximum Aggregate Size ◽  
Fine Aggregate ◽  
Hybrid Fibers ◽  
River Sand ◽  
Ductility Index ◽  
Compressive And Flexural Strengths

The concrete used in highway structures such as pavements, bridge approach slabs or bridge decks are deteriorated much faster rate than other concrete structures due to environmental and traffic loads leading to sudden failure and/or more cracking potential. The present paper investigates experimentally the development of ductile concrete mixtures. Twenty-four mixtures with three types of fibers (PVA, Hocked steel fiber and Nylo-mono) were used. River sand as a fine aggregate and coarse aggregate with a maximum aggregate size of (9.5 mm) were adopted. Fly ash was used as a replacement of Portland cement with three ratios. Compressive and flexural strengths tests were achieved at different curing ages (7, 28 and 90 days) to determine the stress and ductility indexes. The results show that  due to more fly ash content there is an increase in the stress index and decrease in the ductility index for mixtures containing 1% steel and 1% PVA fibers by volume. In addition, the results demonstrated that using of Nylo-mono enhances the ductility index better than PVA. Finally, the use of 2% by volume hybrid fiber (PVA0.5+Steel.0%+Nylo-mono 0.5) achieved a ductile concrete mixture that has a ductility index nine times higher than that of plain concrete.  

Sign in / Sign up

Export Citation Format

Share Document