scholarly journals The Statistical Hypothesis Verification to Influence of Addition of Metakaolin and Silica Fume on Compressive Strength and Chloride Ion Penetration of High Strength Concrete

2011 ◽  
Vol 15 (1) ◽  
pp. 215-225 ◽  
Author(s):  
Jeong Wook Min
Keyword(s):  
Compressive Strength ◽  
Silica Fume ◽  
High Strength Concrete ◽  
Chloride Ion ◽  
High Strength ◽  
Statistical Hypothesis ◽  
Strength Concrete ◽  
Chloride Ion Penetration ◽  
Ion Penetration

scholarly journals Mechanical Properties of High Strength Concrete Containing Nano SiO2 Made from Rice Husk Ash in Southern Vietnam

Crystals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 932
Author(s):  
Huu-Bang Tran ◽  
Van-Bach Le ◽  
Vu To-Anh Phan
Keyword(s):  
Compressive Strength ◽  
Rice Husk ◽  
High Strength Concrete ◽  
Rice Husk Ash ◽  
Chloride Ion ◽  
High Strength ◽  
Ion Permeability ◽  
Strength Concrete ◽  
Nano Sio2 ◽  
Southern Vietnam

This paper presents the experimental results of the production of Nano-SiO2 (NS) from rice husk ash (RHA) and the engineering properties of High Strength Concrete (HSC) containing various NS contents. Firstly, the mesoporous silica nanoparticles were effectively modulated from RHA using NaOH solution, and subsequently precipitated with HCl solution until the pH value reached 3. The optimum synthesis for the manufacture of SiO2 nanoparticles in the weight ratio of RHA/NaOH was 1:2.4, and the product was calcined at 550 °C for 2 h. The EDX, XRD, SEM, TEM, FT-IR, and BET techniques were used to characterize the NS products. Results revealed that the characteristics of the obtained NS were satisfactory for civil engineering materials. Secondly, the HSC was manufactured with the aforementioned NS contents. NS particles were added to HSC at various replacements of 0, 0.5, 1.0, 1.5, 2.0, and 2.5% by the mass of the binder. The water-to-binder ratio was remained at 0.3 for all mixes. The specimens were cured for 3, 7, 28, 25 days under 25 ± 2 °C and a relative humidity of 95% before testing compressive and flexural strengths. Chloride ion permeability was investigated at 28 and 56 days. Results indicated that the addition of NS dramatically enhanced compressive strength, flexural strength, chloride ion resistance, and reduced chloride ion permeability compared to control concrete. The optimal NS content was found at 1.5%, which yielded the highest strength and lowest chloride ion permeability. Next, the development of flexural and compressive strengths with an age curing of 3–28 days can be analytically described by a logarithmic equation with R2 ≥ 0.74. The ACI code was used, and the compressive strength at t-day was determined based on 28 days with R2 ≥ 0.95. The study is expected to solve the redundancy of waste RHA in southern Vietnam by making RHA a helpful additive when producing high-strength concrete and contributing meaningfully to a sustainable environment.

Analysis of Post-Combustion High-Strength Concrete Compressive Strength Using Polypropylene Fibers

2020 ◽  
Vol 26 (1) ◽  
pp. 118-127
Author(s):  
Teuku Budi Aulia ◽  
Muttaqin Muttaqin ◽  
Mochammad Afifuddin ◽  
Zahra Amalia
Keyword(s):  
Compressive Strength ◽  
Thermal Stress ◽  
Silica Fume ◽  
High Temperatures ◽  
High Strength Concrete ◽  
High Strength ◽  
Polypropylene Fibers ◽  
Concrete Compressive Strength ◽  
Strength Concrete ◽  
Maximum Value

High-strength concrete is vulnerable to high temperatures due to its high density. The use of polypropylene fibers could prevent structure explosion by forming canals due to melted fibers during fire, thus release its thermal stress. This study aims to determine the effect of polypropylene fibers on compressive strength of high-strength concrete after combustion at 400ºC for five hours. High-strength concrete was made by w/c-ratio 0.3 with cement amount 550 kg/m3 and added with silica fume 8% and superplasticizer 4% by cement weight. The variations of polypropylene fibers were 0%, 0.2% and 0.4% of concrete volume. The compression test was carried out on standard cylinders Ø15/30 cm of combustion and without combustion specimens at 7 and 28 days. The results showed that compressive strength of high-strength concretes without using polypropylene fibers decreased in post-combustion compared with specimens without combustion, i.e., 0.81% at 7 days and 23.42% at 28 days. Conversely, the use of polypropylene fibers can increase post-combustion compressive strength with a maximum value resulted in adding 0.2% which are 25.52% and 10.44% at 7 and 28 days respectively. It can be concluded that the use of polypropylene fibers is effective to prevent reduction of high-strength concrete compressive strength that are burned at high temperatures.

Effects of Fly Ash and Ground Granulated Blast-Furnaces Slag on Properties of High-Strength Concrete

2009 ◽  
Vol 405-406 ◽  
pp. 219-225 ◽  
Author(s):  
Ji Liang Wang ◽  
Kai Min Niu ◽  
Zhi Feng Yang ◽  
Ming Kai Zhou ◽  
Li Qun Sun ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Fly Ash ◽  
High Strength Concrete ◽  
Chloride Ion ◽  
High Strength ◽  
Volume Stability ◽  
Strength Concrete ◽  
Granulated Blast Furnace Slag ◽  
Chloride Ion Penetration ◽  
Ameliorative Effect

Effects of fly ash and ground granulated blast-furnace slag (GGBFS) on workability, strength, volume stability and durability of HSC are investigated. Results show that fly ash and GGBFS can improve the workability, increase the later strength of high strength concrete (HSC) remarkably, and reduce the brittleness. In addition, the ameliorative effect of GGBFS on HSC brittleness is more remarkable. With the increase of fly ash and GGBFS, the early elastic modulus of HSC reduces. The elastic modulus is similar to the controlled sample when the load is applied after 60d curing. The fly ash and GGBFS can improve HSC’s resistance to chloride ion penetration significantly. However, the effects of fly ash and GGBFS on freezing-hawing resistance of HSC are not obvious. Besides, the fly ash will reduce freezing-hawing resistance of HSC only when the content of mineral powder is up to 36%.

scholarly journals Influence of Different Drying Conditions on High Strength Concrete Compressive Strength

10.14311/228 ◽  
2001 ◽  
Vol 41 (3) ◽  
Author(s):  
M. Safan ◽  
A. Kohoutková
Keyword(s):  
Compressive Strength ◽  
Silica Fume ◽  
High Strength Concrete ◽  
High Strength ◽  
Strength Development ◽  
Concrete Compressive Strength ◽  
Strength Concrete ◽  
Development Rates ◽  
Drying Conditions

The influence of different drying conditions on the compressive strength and strength development rates of high strength concrete up to an age of 28 days was evaluated. Two HSC mixes with and without silica fume addition were used to cast cubes of 10 cm size. The cubes were stored in different drying conditions until the age of testing at 3, 7, 28 days.

Effect of Silica Fume and Fly Ash on Compressive Strength and Weight Loss of High Strength Concrete Material in Sulfuric and Acetic Acid Attack

2017 ◽  
Vol 748 ◽  
pp. 301-310 ◽  
Author(s):  
Wei Liu ◽  
Hong Lin Tan ◽  
Cheng Lin Ni ◽  
Zhi Bin Chen ◽  
Tian Zong Luo ◽  
...  
Keyword(s):  
Weight Loss ◽  
Compressive Strength ◽  
Acetic Acid ◽  
Fly Ash ◽  
Silica Fume ◽  
High Strength Concrete ◽  
High Strength ◽  
Corrosion Mechanism ◽  
Acid Attack ◽  
Strength Concrete

This issue mainly studied the compressive strength and weight loss of high strength concrete in sulfuric and acetic acid attack. Different substitution amounts of silica fume and fly ash single single incorporated and co-incorporated in cement to form high strength concrete. Then weight losses, XRD and SEM were carried out to investigate compressive strength and acid resistance corrosion mechanism after leaching in 5% H2SO4 and 5% CH3COOH solution for 28 days. The results show S10F12 improves the compressive strength by 29.6%, 40.5% and 28.4% in 7, 28 and 56 days curing respectively compared to OPC. The improvement of resistant to 5% H2SO4 and 5% CH3COOH of S10F12 is 38.3% and 112.5% for 28 days immersion respectively, and S10f12 still has compressive strength of 58.8 MP and 45.9 MPa under 5% H2SO4 and 5% CH3COOH attack while OPC only has 38.8MPa and 21.6 MPa after 28 days immersion.

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