STUDY OF STRENGTH DEVELOPMENT OF HIGH CALCIUM FLYASH BASED GEOPOLYMER CONCRETE USING M-SAND AS FINE AGGREGATE

Despite extensive in-depth research into high calcium fly ash geopolymer concretes and a number of proposed methods to calculate the mix proportions, no universally applicable method to determine the mix proportions has been developed. This paper uses an artificial neural network (ANN) machine learning toolbox in a MATLAB programming environment together with a Bayesian regularization algorithm, the Levenberg-Marquardt algorithm and a scaled conjugate gradient algorithm to attain a specified target compressive strength at 28 days. The relationship between the four key parameters, namely water/solid ratio, alkaline activator/binder ratio, Na2SiO3/NaOH ratio and NaOH molarity, and the compressive strength of geopolymer concrete is determined. The geopolymer concrete mix proportions based on the ANN algorithm model and contour plots developed were experimentally validated. Thus, the proposed method can be used to determine mix designs for high calcium fly ash geopolymer concrete in the range 25–45 MPa at 28 days. In addition, the design equations developed using the statistical regression model provide an insight to predict tensile strength and elastic modulus for a given compressive strength.

Download Full-text

Influence of High-Calcium Ash Composition on the Composite Binders’ Properties

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.316.1019 ◽

2021 ◽

Vol 316 ◽

pp. 1019-1024

Author(s):

O. A. Ignatova ◽

A. A. Dyatchina

Keyword(s):

Mechanical Properties ◽

Chemical Composition ◽

Cement Stone ◽

Normal Density ◽

Fine Aggregate ◽

Equivalent Amount ◽

High Calcium ◽

Composition Structure ◽

Kinetics Of ◽

Positive Effect

The paper presents the studies’ results of chemical composition, structure, and physico-mechanical properties of high-calcium ashes from the Kansk-Achinsk coals (2017-2019 selection). It was found that ash has a complex poly-mineral composition and contains hydraulically active minerals and oxides of СаОfr, β-C2S, CA, C3A, C4AF, C2F, CaSO4. According to the content of CaOfr, MgO does not meet standards’ requirements. The uniformity of the volume change is maintained by the composition with 50% of cement. The structure and hardening kinetics of ash and ash-cement stone compositions, obtained from the test of normal density, were analyzed. It was established that the hardening of compositions with ash from the Kansk-Achinsk coals was largely influenced by ash minerals. An equivalent amount of cement in composite binders cannot be replaced. In order to obtain a positive effect, compositions with ash instead cement of no more than 30% and a part of fine aggregate, without exceeding the ratio of ash: cement = 1: 1, should be used.

Download Full-text

Strength and Durability Performance of Alkali-Activated Rice Husk Ash Geopolymer Mortar

The Scientific World JOURNAL ◽

10.1155/2014/209584 ◽

2014 ◽

Vol 2014 ◽

pp. 1-10 ◽

Cited By ~ 20

Author(s):

Yun Yong Kim ◽

Byung-Jae Lee ◽

Velu Saraswathy ◽

Seung-Jun Kwon

Keyword(s):

Compressive Strength ◽

Rice Husk ◽

Rice Husk Ash ◽

Polymerization Reaction ◽

Strength Development ◽

Geopolymer Concrete ◽

Portland Cement Concrete ◽

Mix Proportion ◽

Strength And Durability ◽

Alkali Activated

This paper describes the experimental investigation carried out to develop the geopolymer concrete based on alkali-activated rice husk ash (RHA) by sodium hydroxide with sodium silicate. Effect on method of curing and concentration of NaOH on compressive strength as well as the optimum mix proportion of geopolymer mortar was investigated. It is possible to achieve compressive strengths of 31 N/mm2and 45 N/mm2, respectively for the 10 M alkali-activated geopolymer mortar after 7 and 28 days of casting when cured for 24 hours at 60°C. Results indicated that the increase in curing period and concentration of alkali activator increased the compressive strength. Durability studies were carried out in acid and sulfate media such as H2SO4, HCl, Na2SO4, and MgSO4environments and found that geopolymer concrete showed very less weight loss when compared to steam-cured mortar specimens. In addition, fluorescent optical microscopy and X-ray diffraction (XRD) studies have shown the formation of new peaks and enhanced the polymerization reaction which is responsible for strength development and hence RHA has great potential as a substitute for ordinary Portland cement concrete.

Download Full-text

Resistance to Sulfuric Acid Corrosion of Geopolymer Concrete Based on Different Binding Materials and Alkali Concentrations

Materials ◽

10.3390/ma14237109 ◽

2021 ◽

Vol 14 (23) ◽

pp. 7109

Author(s):

Wei Yang ◽

Pinghua Zhu ◽

Hui Liu ◽

Xinjie Wang ◽

Wei Ge ◽

...

Keyword(s):

Compressive Strength ◽

Corrosion Resistance ◽

Sulfuric Acid ◽

Fly Ash ◽

Acid Corrosion ◽

Geopolymer Concrete ◽

High Calcium ◽

High Calcium Fly Ash ◽

Naoh Solution ◽

Sulfuric Acid Corrosion

Geopolymer binder is expected to be an optimum alternative to Portland cement due to its excellent engineering properties of high strength, acid corrosion resistance, low permeability, good chemical resistance, and excellent fire resistance. To study the sulfuric acid corrosion resistance of geopolymer concrete (GPC) with different binding materials and concentrations of sodium hydroxide solution (NaOH), metakaolin, high-calcium fly ash, and low-calcium fly ash were chosen as binding materials of GPC for the geopolymerization process. A mixture of sodium silicate solution (Na2SiO3) and NaOH solution with different concentrations (8 M and 12 M) was selected as the alkaline activator with a ratio (Na2SiO3/NaOH) of 1.5. GPC specimens were immersed in the sulfuric acid solution with the pH value of 1 for 6 days and then naturally dried for 1 day until 98 days. The macroscopic properties of GPC were characterized by visual appearance, compressive strength, mass loss, and neutralization depth. The materials were characterized by SEM, XRD, and FTIR. The results indicated that at the immersion time of 28 d, the compressive strength of two types of fly ash-based GPC increased to some extent due to the presence of gypsum, but this phenomenon was not observed in metakaolin-based GPC. After 98 d of immersion, the residual strength of fly ash based GPC was still higher, which reached more than 25 MPa, while the metakaolin-based GPC failed. Furthermore, due to the rigid 3D networks of aluminosilicate in fly ash-based GPC, the mass of all GPC decreased slightly during the immersion period, and then tended to be stable in the later period. On the contrary, in metakaolin-based GPC, the incomplete geopolymerization led to the compressive strength being too low to meet the application of practical engineering. In addition, the compressive strength of GPC activated by 12 M NaOH was higher than the GPC activated by 8 M NaOH, which is owing to the formation of gel depended on the concentration of alkali OH ion, low NaOH concentration weakened chemical reaction, and reduced compressive strength. Additionally, according to the testing results of neutralization depth, the neutralization depth of high-calcium fly ash-based GPC activated by 12 M NaOH suffered acid attack for 98 d was only 6.9 mm, which is the minimum value. Therefore, the best performance was observed in GPC prepared with high-calcium fly ash and 12 M NaOH solution, which is attributed to gypsum crystals that block the pores of the specimen and improve the microstructure of GPC, inhibiting further corrosion of sulfuric acid.

Download Full-text

Study of Proportional Variation of Geopolymer Concrete which Self Compacting Concrete

Journal of Advanced Civil and Environmental Engineering ◽

10.30659/jacee.2.2.65-75 ◽

2019 ◽

Vol 2 (2) ◽

pp. 65

Author(s):

Purwanto P. ◽

Himawan Indarto

Keyword(s):

Compressive Strength ◽

Fly Ash ◽

Power Plant ◽

Portland Cement ◽

Fine Aggregate ◽

Geopolymer Concrete ◽

Conventional Concrete ◽

Basic Characteristics ◽

Carbon Dioxide Co2 ◽

Proportional Variation

Portland cement production process which is the conventional concrete constituent materials always has an impact on producing carbon dioxide (CO2) which will damage the environment. To maintain the continuity of development, while maintaining the environment, Portland cement substitution can be made with more environmentally friendly materials, namely fly ash. The substitution of fly ash material in concrete is known as geopolymer concrete. Fly ash is one of the industrial waste materials that can be used as geopolymer material. Fly ash is mineral residue in fine grains produced from coal combustion which is mashed at power plant power plant [15]. Many cement factories have used fly ash as mixture in cement, namely Portland Pozzolan Cement. Because fly ash contains SiO2, Al2O3, P2O3, and Fe2O3 which are quite high, so fly ash is considered capable of replacing cement completely.This study aims to obtain geopolymer concrete which has the best workability so that it is easy to work on (Workable Geopolymer Concrete / Self Compacting Geopolymer Concrete) and obtain the basic characteristics of geopolymer concrete material in the form of good workability and compressive strength. In this study, geopolymer concrete is composed of coarse aggregate, fine aggregate, fly ash type F, and activators in the form of NaOH and Na2SiO3 Be52. In making geopolymer concrete, additional ingredients such as superplastizer are added to increase the workability of geopolymer concrete. From this research, the results of concrete compressive strength above fc' 25 MPa and horizontal slump values reached 60 to 80 centimeters.

Download Full-text

Hydration and strength development of binder based on high-calcium oil shale fly ash

Cement and Concrete Research ◽

10.1016/s0008-8846(98)00058-1 ◽

1998 ◽

Vol 28 (6) ◽

pp. 829-839 ◽

Cited By ~ 13

Author(s):

C Freidin

Keyword(s):

Fly Ash ◽

Oil Shale ◽

Strength Development ◽

High Calcium

Download Full-text

Flexural Behaviour of Reinforced Geopolymer Concrete Incorporated with Hazardous Heavy Metal Waste Ash and Glass Powder

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1048.345 ◽

2022 ◽

Vol 1048 ◽

pp. 345-358

Author(s):

A. Kumar Suresh ◽

M. Muthukannan ◽

A.D.K.B. Irene ◽

K. Kumar Arun ◽

A. Chithambar Ganesh

Keyword(s):

Glass Powder ◽

Ductile Failure ◽

Waste Glass ◽

Flexural Behavior ◽

Fine Aggregate ◽

Geopolymer Concrete ◽

Weight Percentage ◽

Toughness Index ◽

Waste Glass Powder ◽

The Impact

The flexural behavior of Incinerated Bio-Medical Waste Ash (IBWA) – Ground Granulated Blast Furnace Slag (GGBS) based Reinforced Geopolymer Concrete (RGPC) beams with Waste Glass Powder (WGP) as fine aggregate is explored in this research. The fine aggregate (M-Sand) is substituted by varying the waste glass powder as 0 percent, 5 percent, 10 percent, 15 percent, 20 percent, 25 percent, 30 percent, 35 percent, 40 percent, 45 percent, and 50 percent, and the mixture is cured under atmospheric curing. The impact of the WGP weight percentage on the flexural behavior of GPC beams is analyzed. The conduct of RGPC beams varies from that of ordinary Portland Concrete (OPC) beams, which is defined and examined. Deflection, ductility factor, flexural strength, and toughness index were measured as flexural properties for beams. In contrast to the reference beams, the RGPC beams containing 50% Waste Glass Powder as fine aggregate demonstrated a major increase in cracking resistance, serviceability, and ductility, according to the experimental finding. The RGPC beam without WGP ended in failure with a brittle manner whereas those beams with WGP encountered ductile failure. The RGPC beams' load ability improved by up to 50% as the weight percentage of WGP was enhanced.

Download Full-text