scholarly journals Development and Evaluation of Nano-Silica Sustainable Concrete

2021 ◽  
Vol 11 (7) ◽  
pp. 3041
Author(s):  
Habib H. Alqamish ◽  
Adil K. Al-Tamimi

In the last decade, nanomaterials made a major breakthrough in the concrete industry by providing the concrete with unique properties. Earlier studies have shown improvement in the early strength of concrete that can accelerate the construction process. In this study, 1% and 2% of nano-silica were added to concrete mixtures that contain 30% and 70% ground granulated blast-furnace slag (GGBS). Adding 1% of nano-silica to the 30% GGBS mixture showed an increase in the compressive strength by 13.5%, 7.8%, 8.1%, and 2.2% at one day, three days, seven days, and twenty-eight days, respectively. The 2% of nano-silica increased the 30% GGBS mixture’s compressive strength less effectively by 4.3%, 7.6%, and 4.9% at three days, seven days, and 28 days, respectively, when compared to the 1%. On the other hand, adding 1% and 2% of nano-silica reduced the 70% GGBS mixtures’ compressive strength. Moreover, nano-silica reduced the deformability of the mixtures significantly, which caused the increase in the Young’s modulus. The flexural strength of the 30% GGBS mixtures had similar behavior as the 28-day compressive strength. On the other hand, the flexural strength of the 70% GGBS mixtures increased as the nano-silica increased. Nano-silica addition improved the microstructure and the interface structure of the mixtures due to its high pozzolanic activity and the nano-filler effect, which is confirmed by RCPT results and SEM images.

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1477 ◽  
Author(s):  
Ioana-Codruţa Mirică ◽  
Gabriel Furtos ◽  
Bogdan Bâldea ◽  
Ondine Lucaciu ◽  
Aranka Ilea ◽  
...  

The aim of this study was to evaluate the correlation between the percent of inorganic filler by weight (wt. %) and by volume (vol. %) of 11 flowable resin composites (FRCs) and their mechanical properties. To establish the correlation, the quantity of inorganic filler was determined by combustion and shape/size analyzed by SEM images. The compressive strength (CS), flexural strength (FS), and flexural modulus (FM) were determined. The CS values were between 182.87-310.38 MPa, the FS values ranged between 59.59 and 96.95 MPa, and the FM values were between 2.34 and 6.23 GPa. The percentage of inorganic filler registered values situated between 52.25 and 69.64 wt. % and 35.35 and 53.50 vol. %. There was a very good correlation between CS, FS, and FM vs. the inorganic filler by wt. % and vol. %. (R2 = 0.8899–0.9483). The highest regression was obtained for the FM values vs. vol. %. SEM images of the tested FRCs showed hybrid inorganic filler for Filtek Supreme XT (A3) and StarFlow (A2) and a homogeneous type of inorganic filler for the other investigated materials. All of the FS values were above 50 MPa, the ISO 4049/2019 limit for FRCs.


2017 ◽  
Vol 12 (2) ◽  
pp. 101-106 ◽  
Author(s):  
Galyna Kotsay

Abstract Application of nano-materials in cement products significantly, improves their properties. Of course, the effectiveness of the materials depends on their quantity and the way they are introduced into the system. So far, amongst nano-materials used in construction, the most preferred was nano-silica. This research investigated the effect of synthetic precipitated nano-silica on the cement hydration as well as, on the physical and mechanical properties of pastes and mortars. Obtained results showed that admixture of nano-silica enhanced flexural and compressive strength of cement after 2 and 28 days, however, only when admixture made up 0.5% and 1.0%. On the other hand, the use of nano-silica in the amount 2% had some limitations, due to its ability to agglomerate, which resulted in deterioration of the rheological and mechanical properties.


2021 ◽  
Vol 23 (1) ◽  
pp. 11-15
Author(s):  
Ahmad Hamas Sorimatua Harahap ◽  
Sumargo ◽  
Nursyafril

This paper describes experimental results that focus on impacts of elevated temperature on concrete with GGBFS. GGBFS from waste of steel factory PT Krakatau Steel Tbk. has been discovered to be appropriate for geopolymer cement as substitute for cement in concrete. Normal concrete and GGBFS concrete beams (150×150×750mm) and cylindrical (150×300mm) with 40% GGBFS content as substitute of cement weight were burned for two hours, which the first beam was burned at 600°C, second beam at 700°C and third beam at 800°C. After cooling to room temperature, cylindrical and beams were tested. Compressive strength, modulus of elasticity and flexural strength were examined and compared. The results show that GGBFS increased durability of concrete and might be utilized in applications including elevated temperatures. High temperature exposure causes compressive strength of normal concrete decreased extremely up to 69.08%, compared to GGBFS concrete only 46.21%. Flexural strength decreased to 30.37% when the temperature rises to 700°C. Furthermore, it decreased significantly to 50.82% when the temperature reached 800°C.


2016 ◽  
Vol 249 ◽  
pp. 108-111
Author(s):  
Michal Ženíšek ◽  
Tomáš Vlach ◽  
Lenka Laiblová

Reactive powder concrete (RPC) is cement composite which is characterized by an absence of coarse aggregate. That resulted in a greater homogeneity of the mixture and thus also in a higher compressive strength. On the other side, the absence of coarse aggregate and typically a large volume of the paste lead to the deterioration of some of the properties of concrete. This paper deals with the relationship between maximum aggregate size and flexural strength of the reactive powder concrete without dispersed reinforcement. Quartz sand with maximum grain size of 1, 2 and 4 mm was used for the experiments. The flexural strength was measured through the four-point bending test on prisms 100 x 100 x 400 mm. Further, the quartz powder and ground granulated blast furnace slag were used as addition and compared with each other. The results of the experiments showed that the flexural strength grows with decreasing aggregate size. This tendency was observed in mixtures with quartz powder and also with ground granulated blast furnace slag. On the contrary, the compressive strength was independent on aggregate size, but dependent on the type of used addition.


2020 ◽  
Vol 15 (1) ◽  
pp. 47-57
Author(s):  
Alena Sičáková ◽  
Erika Figmigová ◽  
Matej Špak

Abstract Currently, the consumption of blended cements is increasing all over the world. This is due to environmental, technical and economic reasons. Among the additives mixed with ordinary Portland cement, ground granulated blast furnace slag and fly ash are of particular significance. However, some regions may lack standard additives, and vice versa, may be rich in natural pozzolans. This paper is focused on the perlite as a natural pozzolanic material which is locally available. This study presents the results of the application of perlite as a component of blended cements in different proportions, representing binary and ternary compositions, and compares it with standard additives (fly ash and ground granulated blast furnace slag). The time development of both compressive and flexural strength, including results of 2, 7, 28 and 90-day testing, is analyzed. Perlite binders show acceptable time development of strengths, which is comparable to conventional blended binders based on ground granulated blast furnace slag and fly ash and do not constitute a technological barrier. With a higher dose of perlite, the time increase in flexural strength is slower, but the rate of increase in compressive strength does not change substantially. Flexural strength of 4.1–6.2 MPa and compressive strength of 18.8–38.5 MPa are sufficient for a number of practical applications and are expected to meet the required limits. An improvement of strengths in the later period (90 days) was also confirmed.


2021 ◽  
Vol 13 (1) ◽  
pp. 357
Author(s):  
Duc Thanh Tran ◽  
Yunsu Lee ◽  
Han Seung Lee ◽  
Hyun-Min Yang ◽  
Jitendra Kumar Singh

γ-Dicalcium silicate (γ-C2S) is known for its strong carbonation reactivity by which it can capture atmospheric carbon dioxide (CO2), thus, it can be used in construction industries. This paper aims to study the effects of γ-C2S on the properties of ground granulated blast-furnace slag (GGBFS) containing cement mortar and paste in natural and accelerated carbonation curing. The compressive strength of 5% γ-C2S (G5) added to GGBFS cement mortar is higher compared with the control one in natural carbonation (NC) and accelerated carbonation (AC) up to 14 days of curing, but once the curing duration is increased, there is no significant improvement with the compressive strength observed. The compressive strength of AC-cured mortar samples is higher than that of NC. The scanning electron microscopy (SEM) images show that the AC samples exhibited compact, uniform, and regular morphology with less in porosity than the NC samples. X-ray diffraction (XRD) and Fourier transform infra-red (FT-IR) results confirmed the formation of calcium carbonate (calcite: CC) as carbonated products in paste samples, which make the surface dense and a defect-free matrix result in the highest compressive strength. The decomposition of AC samples around 650–750 °C revealed the well-documented and stable crystalline CC peaks, as observed by thermogravimetry analysis (TGA). This study suggests that γ-C2S added to concrete can capture atmospheric CO2 (mostly generated from cement and metallurgy industries), and make the concrete dense and compact, resulting in improved compressive strength.


2022 ◽  
Vol 69 (1) ◽  
Author(s):  
Lamiaa M. Omer ◽  
Mohamed S. Gomaa ◽  
Waleed H. Sufe ◽  
Alaa A. Elsayed ◽  
Hany A. Elghazaly

AbstractThe durability of reinforced concrete (RC) pipes depends upon the corrosion resistance of the reinforcing steel and the resistance of concrete mixes against an aggressive environment. This research paper aims to compare the performance of R.C. pipes made of ordinary Portland cement (OPC) concrete mixtures with others made of two different geopolymer concrete mixes based on different ratios of granulated blast furnace slag (GBFS), fly ash (FA), and pulverized red brick (RB) subjected to three different environments, ambient, tap water (TW), and an aggressive environment, and a solution of 10% magnesium sulfates + 5% chloride (MS-CL). An accelerated corrosion setup has been applied to accelerate the corrosion process in the tested samples. The evaluation of change of compressive strength of concrete and microstructure of different mixes was investigated too. Fourier transform infrared (FTIR) spectroscopy has been studied on all pipes. Geopolymer concrete mixes based on 90% GBFS and 10% RB show better results in all cases. Geopolymer concrete mixes based on 63% GBFS, 27% FA, and 10% RB increase the concrete compressive strength in the magnesium sulfate and chloride environment by 5% compared to tap water. It can be concluded that the geopolymer concrete mixes produced of 90% GBFS and 10% RB perform well under all environments, and its microstructure shows stable behavior in an aggressive environment.


2017 ◽  
Vol 68 (6) ◽  
pp. 1182-1187
Author(s):  
Ilenuta Severin ◽  
Maria Vlad

This article presents the influence of the properties of the materials in the geopolymeric mixture, ground granulated blast furnace slag (GGBFS) + wheat straw ash (WSA) + uncalcined red mud (RMu), and ground granulated blast furnace slag + wheat straw ash + calcined red mud (RMc), over the microstructure and mechanical properties of the synthesised geopolymers. The activation solutions used were a NaOH solution with 8M concentration, and a solution realised from 50%wt NaOH and 50%wt Na2SiO3. The samples were analysed: from the microstructural point of view through SEM microscopy; the chemical composition was determined through EDX analysis; and the compressive strength tests was done for samples tested at 7 and 28 days, respectively. The SEM micrographies of the geopolymers have highlighted a complex structure and an variable compressive strength. Compressive strength varied from 24 MPa in the case of the same recipe obtained from 70% of GGBFS + 25% WSA +5% RMu, alkaline activated with NaOH 8M (7 days testing) to 85 MPa in the case of the recipe but replacing RMu with RMc with calcined red mud, alkaline activated with the 50%wt NaOH and 50%wt Na2SiO3 solution (28 days testing). This variation in the sense of the rise in compressive strength can be attributed to the difference in reactivity of the materials used in the recipes, the curing period, the geopolymers structure, and the presence of a lower or higher rate of pores, as well as the alkalinity and the nature of the activation solutions used.


2021 ◽  
Vol 11 (7) ◽  
pp. 3032
Author(s):  
Tuan Anh Le ◽  
Sinh Hoang Le ◽  
Thuy Ninh Nguyen ◽  
Khoa Tan Nguyen

The use of fluid catalytic cracking (FCC) by-products as aluminosilicate precursors in geopolymer binders has attracted significant interest from researchers in recent years owing to their high alumina and silica contents. Introduced in this study is the use of geopolymer concrete comprising FCC residue combined with fly ash as the requisite source of aluminosilicate. Fly ash was replaced with various FCC residue contents ranging from 0–100% by mass of binder. Results from standard testing methods showed that geopolymer concrete rheological properties such as yield stress and plastic viscosity as well as mechanical properties including compressive strength, flexural strength, and elastic modulus were affected significantly by the FCC residue content. With alkali liquid to geopolymer solid ratios (AL:GS) of 0.4 and 0.5, a reduction in compressive and flexural strength was observed in the case of geopolymer concrete with increasing FCC residue content. On the contrary, geopolymer concrete with increasing FCC residue content exhibited improved strength with an AL:GS ratio of 0.65. Relationships enabling estimation of geopolymer elastic modulus based on compressive strength were investigated. Scanning electron microscope (SEM) images and X-ray diffraction (XRD) patterns revealed that the final product from the geopolymerization process consisting of FCC residue was similar to fly ash-based geopolymer concrete. These observations highlight the potential of FCC residue as an aluminosilicate source for geopolymer products.


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