scholarly journals Corrosion of Steel in High-Strength Self-Compacting Concrete Exposed to Saline Environment

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Hana A. Yousif ◽  
Farqad F. Al-Hadeethi ◽  
Bashar Al-Nabilsy ◽  
Amani N. Abdelhadi
Keyword(s):  
Compressive Strength ◽  
Electrical Resistance ◽  
Corrosion Potential ◽  
Research Work ◽  
High Strength ◽  
Corrosion Current ◽  
Self Compacting Concrete ◽  
Electrochemical Tests ◽  
Structural Applications ◽  
Corrosion Risk

A research work was carried out to investigate the effectiveness of high-strength self-compacting concrete (SF-R) in controlling corrosion of embedded steel. Reinforced concrete cylinders and plain cubes were subjected to 5% NaCl solution. Slump flow, J-ring, V-funnel, compressive strength, electrical resistance, and electrochemical tests were conducted. Corrosion resisting characteristics of steel were examined by monitoring corrosion potential, polarization resistance, corrosion currents, and Tafel plots. The relationship between corrosion current density and corrosion potential was established. Results were compared with characteristics of a grade 40 MPa reference concrete (R) and grade 70 MPa conventional self-compacting concrete (SP). Results indicated that at 270 days of exposure, the corrosion currents for steel in SF-R were 63- and 16-fold lower compared to those of steel in R and SP concretes, respectively. This concrete showed a considerable increase in electrical resistance and compressive strength of 96 MPa at 28 days of exposure. Relying on corrosion risk classification based on corrosion current densities and corrosion potentials, the steel in SF-R concrete is definitely in the passive condition. The splendid durability performance of steel in SF-R concrete linked to adorable self-compacting features could furnish numerous opportunities for future structural applications in severe environmental conditions.

scholarly journals Kajian Karakteristik Beton Memadat Sendiri yang Menggunakan Serat Ijuk (Hal. 54-65)

2018 ◽  
Vol 4 (4) ◽  
pp. 54
Author(s):  
Iis Nurjamilah ◽  
Abinhot Sihotang
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Flexural Strength ◽  
Coarse Aggregate ◽  
Fresh Concrete ◽  
High Strength ◽  
Self Compacting Concrete ◽  
Palm Fiber ◽  
Fiber Concrete ◽  
Dilute Mixture

ABSTRAKKajian karakteristik beton memadat sendiri yang menggunakan serat ijuk merupakan sebuah kajian yang dilakukan untuk mengetahui pengaruh penambahan serat ijuk terhadap karakteristik beton memadat sendiri (SCC). Beton memadat sendiri yang menggunakan serat ijuk (PFSCC) didesain memiliki campuran yang encer, bermutu tinggi (= 40 MPa) dan memiliki persentase kekuatan lentur yang lebih baik. PFSCC  didapatkan dari hasil pencampuran antara semen sebanyak 85%, fly ash 15%, superplastizicer 1,5%, serat ijuk 0%, 0,5%; 1%; 1,5%; 2% dan 3% dari berat binder (semen + fly ash), kadar air 190 kg/m3, agregat kasar 552,47 kg/m3 dan pasir 1.063 kg/m3. Semakin banyak persentase penambahan serat ijuk ke dalam campuran berdampak terhadap menurunnya workability beton segar. Penambahan serat ijuk yang paling baik adalah sebanyak 1%, penambahan tersebut dapat meningkatkan kekuatan tekan beton sebesar 13% dan lentur sebesar 1,8%.Kata kunci: beton memadat sendiri (SCC), beton berserat, beton memadat sendiri yang menggunakan serat ijuk (PFSCC), serat ijuk ABSTRACTThe study of characteristics self compacting concrete using palm fibers is a study conducted to determine the effect of adding palm fibers to characteristics of self compacting concrete (SCC). palm fibers self compacting concrete (PFSCC) is designed to have a dilute mixture, high strength (= 40 MPa), and have better precentage flexural strength. PFSCC was obtained from mixing of 85% cement, 15% fly ash, 1.5% superplastizicer, 0%, 0.5%, 1%, 1.5%, 2% and 3% palm fibers from the weight of binder  (cement + fly ash), water content 190 kg/m3, coarse aggregate 552.47 kg/m3 and sand 1,063 kg/m3. The more persentage palm fibers content added to the mixture makes workability of fresh concrete decreases. The best addition of palm fiber is 1%, this addition can increases the compressive strength 13% and flexural strength 1.8%.Keywords: self compacting concrete (SCC), fiber concrete, Palm fiber self compacting concrete (PFSCC), palm fiber

scholarly journals Utilization of Metakaolin and Calcite: Working Reversely in Workability Aspect—As Mineral Admixture in Self-Compacting Concrete

2018 ◽  
Vol 2018 ◽  
pp. 1-12
Author(s):  
Fatih Özcan ◽  
Halil Kaymak
Keyword(s):  
Compressive Strength ◽  
High Strength ◽  
High Volume ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Mineral Admixture ◽  
Self Compacting Concrete ◽  
Binder Ratio

In this work, utilization of metakaolin (MK) and calcite (C), working reversely in workability aspect, as mineral admixture in self-compacting concrete (SCC), was investigated. MK and C replaced cement in mass basis at various replacement ratios, separately and together. In total, 19 different SCCs were produced. Binder content and water to binder ratio were selected as 500 kg/m3 and 0.4, respectively. Workability tests including slump flow, T50, L-box, and V-funnel tests were performed. Consistency and setting times of binder paste were measured. While replacement of MK with cement increased the amount of plasticiser requirement, calcite worked reversely and decreased it. Reverse influence of MK and C on plasticiser requirement of SCC made possible to produce SCC at total 45% replacement ratio of MK and C together. Samples of SCC were cured in water at 20°C temperature. Compressive strengths of SCC samples were measured up to six months to evaluate the influence of MK and C, separately and together. Ultrasonic pulse velocity, abrasion, and capillary water absorption values of samples were determined at specified age. MK inclusion in concrete reduces workability, while C inclusion increases it. C and MK inclusion together remedied workability of concrete and enabled to produce SCC with high volume of admixtures. Furthermore, C incorporation increased one-day compressive strength, while MK incorporation reduced it in comparison with control concrete. In long term, C inclusion reduced compressive strength; however, MK inclusion increased it. C inclusion remedied one-day strength of concrete when it was used together with MK. MK inclusion remedied long-term compressive strength when it was used together with C and enabled to produce high-strength SCC with high volume of admixtures. SCC containing MK and C together showed better durability-related property.

Durability indicators of high-strength self-compacting concrete with marble and granite wastes and waste foundry exhaust sand using electrochemical tests

2022 ◽  
Vol 317 ◽  
pp. 125907
Author(s):  
Maria Auxiliadora Martins ◽  
Regina Mambeli Barros ◽  
Lucas Ramon Roque da Silva ◽  
Valquiria Claret dos Santos ◽  
Rosa C.C. Lintz ◽  
...  
Keyword(s):  
High Strength ◽  
Self Compacting Concrete ◽  
Electrochemical Tests

scholarly journals Effect of basalt fibres on the parameters of fracture mechanics of MB modifier based high-strength concrete

2018 ◽  
Vol 251 ◽  
pp. 02003 ◽  
Author(s):  
Makhmud Kharun ◽  
Dmitry Koroteev
Keyword(s):  
Compressive Strength ◽  
Fracture Mechanics ◽  
High Strength Concrete ◽  
High Strength ◽  
Critical Energy ◽  
Critical Stress Intensity Factor ◽  
Critical Energy Release Rate ◽  
Environmental Friendliness ◽  
Strength Concrete ◽  
Structural Applications

Basalt fibres (BF) are increasingly studied in structural applications due to its environmental friendliness and good mechanical properties. Mass production of high-strength concrete (HSC) in Russia is mainly associated with the use of organomineral modifiers of the MB series, containing in their composition microsilica, fly ash, hardening regulator and superplasticizer C-3 in different ratios. In our study we produced HSC specimens (without BF, and with 1 wt.% chopped BF) using the modifier MB10-30, with the dimensions of 100x100x100 mm, 100x100x400 mm, 100x100x400 mm with the artificial crack of 25 mm deep in the middle of the span, and also 100х75х400 mm (75 mm height was taken equal to the height of the section above the crack of the 2nd type of prisms). The compressive strength, the tensile strength at bending, the strength at axial tension, the cracking moment, and also the parameters of fracture mechanics, such as: the critical stress intensity factor and the critical energy release rate, at the curing periods of 7, 14, 28, 60 days, have been determined. We also evaluated the influence of crack in the bend element on the value of the cracking moment. The results showed that the inclusion of BF in MB modifier based HSC resulted in a decrease in the compressive strength, however, significantly enhanced its flexure behavior.

Impact of Plasticizers on Technological Properties of Gypsum

2016 ◽  
Vol 865 ◽  
pp. 130-134 ◽  
Author(s):  
Dušan Dolák ◽  
Karel Dvořák
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Mechanical Strength ◽  
Research Work ◽  
High Strength ◽  
Building Industry ◽  
Technological Properties ◽  
Accurate Comparison

Sulphate binders based on gypsum are widely used in building industry. This research work was focused on testing the influence of Melflux plasticizers on the final properties of the gypsum mixture. The aim was to determine the correct concentration of the plasticizer considering workability and improvement of mechanical properties, especially the compressive strength. Different concentrations of plasticizers were tested in mixture of alfa and beta plaster. Each batch was created as paste of normal consistency to create accurate comparison. The results of experiment show significant improvements of mechanical strength of the hardened mixture while maintaining same consistency. This knowledge can be utilized in the design of high-strength sulphate binders.

scholarly journals Effect of Steel Fiber Aspect Ratio on the Properties of High Strength Self Compacting Concrete

2019 ◽  
Vol 9 (2) ◽  
pp. 2938-2941
Keyword(s):  
Compressive Strength ◽  
High Strength Concrete ◽  
High Strength ◽  
Steel Fibers ◽  
Self Compacting Concrete ◽  
Split Tensile Strength ◽  
Strength Concrete ◽  
Fiber Aspect Ratio ◽  
Aspect Ratios ◽  
Hardened Properties

The High strength concrete defined as per IS 456 as the concrete having characteristic compressive strength more than 65 MPa. The self-compacting concrete has lot of advantages including concreting at congested reinforcement locations, better finish, good compaction etc. The inclusion of fibers in the concrete mix decreases the brittle nature of concrete thereby the ductility increases. Different types of fibers are available for inclusion in concrete like steel, glass, polypropylene, basalt, etc. In the present investigation, high strength concrete having characteristic strength of 90 MPa was developed and hooked ended steel fibers are used and the hardened properties are determined. Steel fibers having diameter of 1 mm and lengths of 25 and 50 mm were added to concrete in 0.125%, 0.25% and 0.5% by volume of concrete. Three hardened properties compressive strength, split tensile Strength and flexural strength were determined. Out of the two lengths of fiber i.e with two aspect ratios, the fiber with 50 mm length yielded better results.

scholarly journals Performance of sustainable self-compacting fiber reinforced concrete with substitution of marble waste (MW) and coconut fibers (CFs)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jawad Ahmad ◽  
Fahid Aslam ◽  
Rebeca Martinez-Garcia ◽  
Mohamed Hechmi El Ouni ◽  
Khalid Mohamed Khedher
Keyword(s):  
Experimental Investigation ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Reinforced Concrete ◽  
High Strength ◽  
Fiber Reinforced Concrete ◽  
Self Compacting Concrete ◽  
Pozzolanic Materials ◽  
Passing Ability ◽  
Marble Waste

AbstractSelf compacting concrete (SCC) is special type of concrete which is highly flowable and non-segregated and by its own mass, spreads into the formwork without any external vibrators, even in the presence of thick reinforcement. But SSC is also brittle nature like conventional concrete, which results in abrupt failure without giving any deformation (warning), which is undesirable for any structural member. Thus, self-compacting concrete (SCC) needs some of tensile reinforcement to enhance tensile strength and prevent the unsuitable abrupt failure. But fiber increased tensile strength of concrete more effectively than compressive strength. Hence, it is essential to add pozzolanic materials into fiber reinforced concrete to achieve high strength, durable and ductile concrete. This study is conducted to assess the performance of SCC with substitutions of marble waste (MW) and coconut fiber (CFs) into SCC. MW utilized as cementitious (pozzolanic) materials in percentage of 5.0 to 30% in increment of 5.0% by weight of binder and concrete is reinforced with CFs in proportion of 0.5 to 3.0% in increment of 0.5% by weight of binder. Rheological characteristics were measured through its filling and passing ability by using Slump flow, Slump T50, L-Box, and V-funnel tests while mechanical characteristics were measured through compressive strength, split tensile strength, flexure strength and bond strength (pull out) tests. Experimental investigation show that MW and CFs decrease the passing ability and filling ability of SCC. Additionally, Experimental investigation show that MW up to 20% and CFs addition 2.0% by weight of binder tend to increase the mechanical performance of SCC. Furthermore, statistical analysis (RSM) was used to optimize the combined dose of MW and CFs into SCC to obtain high strength self-compacting concrete.

scholarly journals An Experimental Development on Properties of Concrete with GGBS in Addition with Alkaline Solution of Sodium Hydroxide and Sodium Silicate

2019 ◽  
Vol 8 (2) ◽  
pp. 5306-5310
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
High Strength Concrete ◽  
Research Work ◽  
High Strength ◽  
Blast Furnaces ◽  
Experimental Development ◽  
Strength Concrete ◽  
Binding Material ◽  
Almost All

Becoming modern waste have discovered the need to transfer of mechanical waste, The waste that must be arranged would two be able to be spared to use in some way, among the two modern waste preparing cementatious nature substances can be supplanted as folio include number in cement to separated. Ground Granulated Blast Furnaces Slag (GGBS) which used to be squander from an iron assembling industry, which used to be utilized as substitute of bond in cement because of its characteristic solidifying properties. To increase the strength of the concrete some of the special cements are used. Due to various codal specifications the binding material replacements of GGBS have been restricted up to 80% in maximum. In this project replacement of GGBS is done by an amount of 10% ,20% ,30% and 40%. In accordance with above restrictions the replacement variations in binding material have been decoded in a high strength concrete mixture. The research work have been extensively executed in almost all areas of testing like compressive strength , spilt tensile strength, and flexural strength, and also various primary tests like specific gravity , granular gradation etc. have also been excited to achieve high strength concrete.

Effect Of Specimen Size and Shape on Compressive Strength of Self-Compacting Concrete

2014 ◽  
Vol 7 (2) ◽  
pp. 16-29
Author(s):  
Mohammed Karem Abd ◽  
Zuhair Dhaher Habeeb
Keyword(s):  
Compressive Strength ◽  
Correction Factor ◽  
High Strength Concrete ◽  
High Strength ◽  
Specimen Size ◽  
Self Compacting Concrete ◽  
Normal Concrete ◽  
Cube Strength ◽  
Strength Concrete ◽  
Size And Shape

This study aims to show the effect of specimen size and shape on compressive strength of self-compacting concrete (SCC). The work is divided into two parts, the first was to designed Normal Concrete (NC), High Strength Concrete (HSC) and Self Compacting Concrete (SCC) of strength between (25-70) MPa. from locally available materials. The values percent of cylinder to cube strength were between (0.86-0.9), (0.94-0.96), (0.96-0.99) of NC, HSC and SCC respectively.The second is to investigate the effect of specimen size on compressive strength, the values of correction factor of cube specimens (150*150*150)mm and (100*100*100)mm is (0.89-1.29), (0.98-1.26) and (0.98-1.22) of NC,HSC and SCC respectively. The values of correction factor of cylinder specimens of (150*300) mm and (100*200) mm is (0.88-1.08), (0.93-1.07) and (0.95-1.04) of NC, HSC and SCC respectively.

The Influence of Aggressive Environment with a High Content of Fluoride Ions on the Alloy TiAl6V4 with a Protective Ti-Al-Si Layer

2011 ◽  
Vol 287-290 ◽  
pp. 966-969
Author(s):  
Tomáš Kubatík ◽  
Marcela Kadlecová ◽  
Boleslav Eremiáš ◽  
Eva Kalabisová
Keyword(s):  
Chloride Solution ◽  
Corrosion Potential ◽  
Corrosion Current ◽  
Potential Range ◽  
Fluoride Ions ◽  
Electrochemical Tests ◽  
Aggressive Environment ◽  
Potentiodynamic Curves ◽  
Main Component ◽  
Positive Effect

This work presents results on the influence of fluoride ions on the behavior of layers whose main component is the phase TiAl0.3Si1.7 (called t2 phase), formed on TiAl6V4 substrate. Layers were prepared in AlSi20 melt at 650 ° C for 60 min. Potentiodynamic curves were measured in a chloride solution with 0 and 5000 ppm fluoride. Layer were shifted corrosion potential to more negative values and at the some time reduce the corrosion current density (Im). Values of Im are in the potential range of 300 – 1500 mV (SCE) for TiAl6V4 with Ti-Al-Si layers significantly lower in comparison with Im values found for TiAl6V4 in chloride solution containing 5000 F-. The electrochemical tests showed that Ti-Al-Si layer had marked positive effect on corrosion resistance of TiAl6V4 alloys in aggressive environment with high content of F-.

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