Anti-acid Corrosion Property of Concrete Improved by Microstructure Optimizing

To enhance the performance of anti-acid erosion, silica fume, silicon nitride, organic silicone emulsion agent and fly ash ceramsite are all mixed into concrete as admixture. The acid corrosion environment is simulated by laboratory test. Compressive strength of concrete with different curing ages are tested. Compressive strength and pore distribution of concrete dipping in sulphate and in hydrochloride for 90d are tested. The result shows that concrete with additional materials has better anti-acid corrode performance than the common one. The compressive strength of concrete with additional materials is higher than the common concrete. The pore distribution curve of the concrete with additional materials can keep steady no matter in sulphate or in hydrochloride. This kind of concrete with high anti-acid corrosion durability has been used in the piles construction of the bridges which is surrounded by acid soil and play an important role in enhancing the durability of the bridge.

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Prediction of Compressive Strength of Concrete Using Recycled Materials from Fly Ash Based on Ultrasonic Pulse Velocity and Design of Experiment

Advances in Intelligent Systems and Computing - Computational Intelligence Methods for Green Technology and Sustainable Development ◽

10.1007/978-3-030-62324-1_51 ◽

2020 ◽

pp. 600-612

Author(s):

Le Thang Vuong ◽

Cung Le ◽

Dinh Son Nguyen

Keyword(s):

Compressive Strength ◽

Fly Ash ◽

Design Of Experiment ◽

Ultrasonic Pulse Velocity ◽

Ultrasonic Pulse ◽

Pulse Velocity ◽

Recycled Materials ◽

Compressive Strength Of Concrete

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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.

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Research on Mechanical Performance & Behaviour of Geopolymer Concrete Subjected to Elevated Temperatures

International Journal of Recent Technology and Engineering - 2 ◽

10.35940/ijrte.b1001.0882s819 ◽

2019 ◽

Vol 8 (2S8) ◽

pp. 883-887

Keyword(s):

Compressive Strength ◽

Fly Ash ◽

Silica Fume ◽

Elevated Temperatures ◽

Mechanical Performance ◽

Geopolymer Concrete ◽

Sem Images ◽

Before And After ◽

Alkaline Conditions ◽

Compressive Strength Of Concrete

The investigative studies on mechanical performance & behaviour, of Geopolymer Concrete (GPC) before and after the exposure to elevated temperatures (of 200 0 C -1000 0 C with an increment of 100 0 C). Indicate that the GPC Specimens Exhibited better Compressive strength at higher temperatures than that of those made by regular OPC Concrete with M30 Grade. The chronological changes in the geopolymeric structure upon exposure to these temperatures and their reflections on the thermal behaviour have also been explored. The SEM images indicate GPC produced by fly ash , metakaolin and silica fume, under alkaline conditions form Mineral binders that are not only non-flammable and but are also non-combustible resins and binders. Further the Observations drawn disclose that the mass and compressive strength of concrete gets reduced with increase in temperatures.

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Kuat Tekan Beton Mutu Tinggi dengan Memanfaatkan Fly Ash dan Bubuk Kaca Sebagai Bahan Pengisi

JURNAL SAINTIS ◽

10.25299/saintis.2020.vol20(01).4846 ◽

2020 ◽

Vol 20 (01) ◽

pp. 61-68

Author(s):

Siska Apriwelni ◽

Nugraha Bintang Wirawan

Keyword(s):

Compressive Strength ◽

Fly Ash ◽

Glass Powder ◽

Concrete Mixture ◽

Strength Testing ◽

Concrete Compressive Strength ◽

High Quality ◽

Glass Waste ◽

Powder Addition ◽

Compressive Strength Of Concrete

(ID) Penelitian ini membahas pengaruh kuat tekan beton mutu tinggi dengan memanfaatkan limbah fly ash dan limbah kaca. Tujuan dari penelitian ini untuk mengetahui kuat tekan beton pada masing-masing variasi, mengetahui persentase campuran beton untuk menghasilkan kuat tekan maksimum, dan mengetahui apakah fly ash dan serbuk kaca efektif digunakan secara bersamaan sebagai bahan campuran beton. Komposisi fly ash terdiri dari 5 variasi yaitu persentase 0%, 5%, 10%, 15%, dan 20%. Sedangkan untuk komposisi serbuk kaca terdiri dari 2 variasi yaitu persentase 5% dan 10%. Jumlah benda uji 30 buah silinder berukuran diameter 15 cm dan tinggi 30 cm dengan 3 benda uji untuk setiap variasi. Perencanaan campuran beton menggunakan SNI 03-2834-2000 yang dimodifikasi. Pengujian kuat tekan diuji pada umur beton 28 hari. Beton dengan fly ash 0% dan serbuk kaca 10% memiliki kuat tekan paling tinggi dibandingkan dengan beton dengan tambahan fly ash, yaitu 46,77%. Selain itu, dapat disimpulkan bahwa semakin bertambahnya jumlah persentase serbuk kaca yang digunakan menunjukkan bahwa kuat tekan beton semakin bertambah juga. Penambahan fly ash pada campuran beton mempengaruhi kuat tekan beton yang dihasilkan. Pada variasi fly ash 0% memiliki kuat tekan tertinggi baik pada saat campuran serbuk kaca 5%dan 10%. Variasi fly ash 15% adalah kondisi optimum campuran beton dengan kuat tekan beton yaitu 43,31 Mpa. Kedua limbah ini dapat dikombinasikan dan dimanfaatkan dengan baik dan digunakan dalam pembuatan beton mutu tinggi. (EN) This study discusses the effect of high quality concrete by utilizing fly ash and glass waste. The purpose of this study is to determine the compressive strength of concrete in each variation, to determine the contribution of concrete to produce compressive strength, and to find out that fly ash and glass powder are effectively used in full as a concrete admixture. Fly ash composition consists of 5 variations, namely the percentage of 0%, 5%, 10%, 15%, and 20%. While for the composition of glass powder consists of 2 variations, namely the percentage of 5% and 10%. The number of specimens is 30 cylinders with a diameter of 15 cm and a height of 30 cm with 3 specimens for each variation. Concrete mixture planning using SNI 03-2834-2000 was developed. Compressive strength testing on concrete age 28 days. Concrete with 0% fly ash and 10% glass powder have the highest compressive strength compared to concrete with additional fly ash, which is 46.77%. In addition, it can increase the amount of glass powder addition that is used to show the concrete compressive strength is increasing as well. The addition of fly ash in the concrete mixture has an effect on the compressive strength of the concrete produced. In the variation of 0% fly ash has the highest compressive strength when the glass powder mixture of 5% and 10%. The 15% fly ash variation is the optimal concrete mixture with compressive strength of 43.31 MPa. These two wastes can be combined and utilized properly and are used in making high quality concrete.

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Experimental Study on Alkali-Activated Slag-Lithium Slag-Fly Ash Environmental Concrete

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.287-290.1237 ◽

2011 ◽

Vol 287-290 ◽

pp. 1237-1240

Author(s):

Lan Fang Zhang ◽

Rui Yan Wang

Keyword(s):

Experimental Study ◽

Compressive Strength ◽

Fly Ash ◽

Setting Time ◽

Alkali Activated Slag ◽

Percent Increase ◽

Compressive Strength Of Concrete ◽

Activated Slag ◽

Lithium Slag ◽

Alkali Activated

The aim of this paper is to study the influence of lithium-slag and fly ash on the workability , setting time and compressive strength of alkali-activated slag concrete. The results indicate that lithium-slag and fly-ash can ameliorate the workability, setting time and improve the compressive strength of alkali-activated slag concrete，and when 40% or 60% slag was replaced by lithium-slag or fly-ash, above 10 percent increase in 28-day compressive strength of concrete were obtained.

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On Effects of Fly Ash as a Partial Replacement of Cement on Concrete Strength

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.204-208.3970 ◽

2012 ◽

Vol 204-208 ◽

pp. 3970-3973

Author(s):

Reagan J. Case ◽

Kai Duan ◽

Thuraichamy G. Suntharavadivel

Keyword(s):

Compressive Strength ◽

Fly Ash ◽

Concrete Strength ◽

Cementitious Materials ◽

Partial Replacement ◽

Replacement Ratio ◽

Interface Reactions ◽

Compressive Strength Of Concrete ◽

Interface Bonding Strength ◽

Large Research

As a part of a large research program aiming at the cementitious materials containing recycled materials at Central Queensland University – Australia, the current paper presents the preliminary results of a study on the effects of fly ash, which is used to replace cement in concrete, on the concrete compressive strength. For this purpose, systematic experiments have been carried out to investigate the influences of fly ash ratio and age. The compressive strength of concrete specimens with replacement ratios of 15%, 30% and 45%, and aged 7 and 28 days are measured and are compared with those of the concrete specimens without fly ash at the same ages. The results demonstrate that the strength of fly ash containing concrete improves more slowly but more strongly with aging, than their fly ash free counterparts, and an optimum fly ash replacement ratio exists where the maximum compressive strength of fly ash containing concrete can be achieved, and the maximum strength for the specimens aged 28 days and above is higher that of fly ash free concrete. Furthermore, the observation strength behaviours are analysed and discussed in terms of the influences of fly ash on interface reactions and interface bonding strength.

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Study on the Deterioration of Concrete under Dry–Wet Cycle and Sulfate Attack

Materials ◽

10.3390/ma13184095 ◽

2020 ◽

Vol 13 (18) ◽

pp. 4095

Author(s):

Fang Liu ◽

Tonghuan Zhang ◽

Tao Luo ◽

Mengzhen Zhou ◽

Kunkun Zhang ◽

...

Keyword(s):

Compressive Strength ◽

Sodium Sulfate ◽

Distribution Curve ◽

Early Stage ◽

Sulfate Attack ◽

Industrial Computed Tomography ◽

Spectrum Distribution ◽

Compressive Strength Of Concrete ◽

Internal Pore Structure ◽

Internal Pore

In order to study the deterioration and mechanism of dry–wet cycles and sulfate attack on the performance of concrete in seaside and saline areas, the deterioration of compressive strength of concrete with different water cement ratios under different erosion environments (sodium sulfate soaking at room temperature and coupling of dry–wet cycling and sodium sulfate) was studied here. At the same time, ICT (industrial computed tomography) and NMR (nuclear magnetic resonance) techniques were used to analyze the internal pore structure of concrete under different erosion environments. The results show that the compressive strength under different erosion environments increases first and then decreases, and the dry–wet cycle accelerates the sulfate erosion. With the increase of dry and wet cycles, larger pores are filled with erosion products and developed into small pores in the early stage of erosion; in the later stage of erosion, the proportion of larger pores increases, and cracks occur inside the sample. In the process of sulfate soaking and erosion, the smaller pores in the concrete account for the majority. As the sulfate erosion continues, the T2 spectrum distribution curve gradually moves right, and the signal intensity of the larger pores increases.

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