scholarly journals The Compressive Strength and Resistivity toward Corrosion Attacks by Chloride Ion of Concrete Containing Type I Cement and Calcium Stearate

2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
Agus Maryoto ◽  
Buntara Sthenly Gan ◽  
Nor Intang Setyo Hermanto ◽  
Rachmad Setijadi
Keyword(s):  
Compressive Strength ◽  
Chloride Ion ◽  
Concrete Surface ◽  
Chloride Ions ◽  
Calcium Stearate ◽  
Type I ◽  
Compressive Strength Test ◽  
Strength Tests ◽  
Concrete Quality ◽  
Infiltration Test

This study aims to determine the effect of calcium stearate on concrete. Three kinds of concrete quality are studied, namely, 20, 30, and 40 MPa. Tests performed in the laboratory comprise a compressive strength test and an infiltration test of chloride ion content. The specimens used were cylinders with a diameter of 150 mm and height of 300 mm. The chloride ion infiltration test was carried out on a cube with sides of 150 mm. The infiltration of ions into the concrete was examined at depths of 1, 2, 4, 6, and 8 cm. Four dosages of calcium stearate were added to the concrete, namely, 0, 0.25, 1.27, and 2.53% for 20 MPa concrete; 0, 0.21, 1.07, and 2.48% for 30 MPa concrete; and 0, 0.19, 0.90, and 1.87% for 40 MPa concrete. The results of compressive strength tests indicate that the amount of calcium stearate that could be safely applied to the concrete was 0.25% of the weight of cement. On the other hand, the infiltration of chloride ions at a depth of 6 cm from the unprotected concrete surface decreased by 87, 69, and 113% for the 20, 30, and 40 MPa concrete, respectively, compared to concrete without calcium stearate. The test shows that the use of calcium stearate in concrete significantly increases its resistivity against corrosion attacks because, in the absence of chloride ions, the process of corrosion does not take place in the concrete.

REDUCTION OF CHLORIDE ION INGRESS INTO REINFORCED CONCRETE USING A HYDROPHOBIC ADDITIVE MATERIAL

2017 ◽  
Vol 79 (2) ◽  
Author(s):  
Agus Maryoto ◽  
Buntara S. Gan ◽  
Han Aylie
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Chloride Ion ◽  
Chloride Ions ◽  
Calcium Stearate ◽  
Corrosion Attack ◽  
Reinforced Concrete Member ◽  
Load Carrying ◽  
Compressive Strength Test ◽  
Infiltration Test

Reinforced concrete structures located in areas near the coast are exposed to potential corrosion attack. Corrosion attack can occur because of the infiltration of chloride ions into concrete. At the initiation of the corrosion process, the load-carrying capacity of a reinforced concrete member will be affected negatively as a function of time. Infiltration of chloride ions into the concrete could be avoided by improving the micro-concrete properties. Enhancement of these properties can be achieved by use of an additive in the concrete. Calcium stearate is a hydrophobic material that can improve the properties of concrete. To determine the optimum contribution in concrete, laboratory experiments were conducted. Calcium stearate was added in varying contents of 0, 0.2, 0.9, and 1.9% of the cement weight. Four types of tests were performed to analyse the contribution of calcium stearate, namely the compressive strength test, absorption test, chloride ion infiltration test, and corrosion test. The results show that an optimum value of the compressive strength of concrete is obtained through the addition of calcium stearate. Besides that, the absorption, chloride ion infiltration, and corrosion value decrease significantly when a higher amount of calcium stearate is added to the concrete.  

scholarly journals Evaluation of Chloride Resistance of Early-Strength Concrete Using Blended Binder and Polycarboxylate-Based Chemical Admixture

2020 ◽  
Vol 10 (8) ◽  
pp. 2972 ◽  
Author(s):  
Taegyu Lee ◽  
Jaehyun Lee
Keyword(s):  
Compressive Strength ◽  
Diffusion Coefficient ◽  
Portland Cement ◽  
Chloride Ion ◽  
Strength Criterion ◽  
Chloride Ions ◽  
Chloride Diffusion ◽  
Chloride Diffusion Coefficient ◽  
Characteristic Strength ◽  
Early Strength

The mixing proportions of concrete were examined with regard to the durability performance and early strength in coastal areas. Research was conducted to improve the C24 mix (characteristic strength of 24 MPa). C35 concrete (characteristic strength of 35 MPa) was selected as a comparison group, as it exhibits the minimum proposed strength criterion for concrete in the marine environment. To secure the early strength of the C24 concrete, 50% of the total ordinary Portland cement (OPC) binder was replaced with early Portland cement (EPC); and to provide durability, 20% was substituted with ground granulated blast-furnace slag (GGBS). In addition, a polycarboxylate (PC)-based superplasticizer was used to reduce the unit water content. The compressive strength, chloride ion diffusion coefficient, chloride penetration depth, and pore structure were evaluated. After one day, the compressive strength improved by 40% when using EPC and GGBS, and an average increase of 20% was observed over 91 days. EPC and GGBS also reduced the overall porosity, which may increase the watertightness of concrete. The salt resistance performance was improved because the rapid early development of strength increased the watertightness of the surface and immobilization of chloride ions, decreasing the chloride diffusion coefficient by 50%.

Development of Fly Ash Based Geopolymer as Erosion Mitigation Coating

2014 ◽  
Vol 699 ◽  
pp. 342-347
Author(s):  
Noor Hafizah Ramli Yusof ◽  
Rashidah Mohamed Hamidi ◽  
Zakaria Man ◽  
Khairun Azizi Azizli ◽  
Mohd Fadhil Nuruddin
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Concrete Surface ◽  
Organic Coating ◽  
Cycle Performance ◽  
Gel Time ◽  
Compressive Strength Test ◽  
Alternative Material ◽  
Treatment Facilities ◽  
Erosion Mitigation

Loss of durability of concrete materials in sewage and chemical treatment facilities exposed to acidic environments is a key issue that affects the life cycle performance. Applications of organic coating such as epoxy and acrylic usually covers the concrete surface by physical addition normally failed to act as an effective coating due to debonding when the organic coating absorbs water. In this work, geopolymer was used as alternative material for concrete coating. Preparation of geopolymer involved fly ash, a materials containing high aluminosilicate and calcium mixed with various concentrations (6, 8 and 12M) of sodium hydroxide (NaOH). Subsequently, all samples were tested and analysed through compressive strength test and gel time. Geopolymers synthesised from 12M NaOH concentration exhibited high compressive strength and low gel time, hence was chosen as a coating for the concretes for the erosion evaluation. Results show that, concretes coated with geopolymers yielded low percentage of mass loss compared to the uncoated concretes. This suggest that geopolymers has high potential to be used as erosion mitigation coating to prevent the concretes from degrading due to the acidic environment.

Effect of Electrochemical Chloride Extraction on the Steel Reinforced Concrete

2008 ◽  
Vol 400-402 ◽  
pp. 221-225 ◽  
Author(s):  
Jian Zhi Xu ◽  
Zhu Ding ◽  
Feng Xing
Keyword(s):  
Compressive Strength ◽  
Steel Surface ◽  
Extraction Efficiency ◽  
Concrete Surface ◽  
Chloride Ions ◽  
High Current ◽  
Steel Reinforced Concrete ◽  
Strong Shift ◽  
Current Densities ◽  
Electrochemical Chloride Extraction

Electrochemical chloride extraction (ECE) is used for the rehabilitation of chloride-contaminated concrete. High current densities of steel surface are applied between the steel and a temporary external anode which is placed on the concrete surface. Anions are pushed away from the cathode (steel reinforcement), and cations are accumulated at the cathode. In this study chloride ions were found in the electrolyte during ECE. The extraction efficiency of chlorides was obvious. After treatment, the amount of chlorides around the reinforcement was greatly reduced. ECE had insignificant effect on the compressive strength. Steel potentials in treated specimens showed a strong shift towards more positive values, while potentials in control specimens remained strongly negative.

scholarly journals The Impact of Chloride and Sulphate Aggressiveness on the Microstructure and Phase Composition of Fly Ash-Slag Mortar

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4430
Author(s):  
Paweł Falaciński ◽  
Agnieszka Machowska ◽  
Łukasz Szarek
Keyword(s):  
Compressive Strength ◽  
Phase Composition ◽  
Sodium Chloride ◽  
Chloride Ion ◽  
Sodium Sulphate ◽  
Chloride Ions ◽  
Ion Concentration ◽  
Pore Liquid ◽  
A Minor ◽  
The Impact

The article discusses the results of examining the impact of aggressive solutions on specimens of mortars with a slag-ash binder. Bar specimens were exposed to unidirectional diffusion of sodium chloride and sodium sulphate for 90 days. Next, the specimens were subjected to flexural and compressive strength tests, ion content tests, XRD phase composition tests, and microstructural SEM-EDS tests. The test results indicated that aggressive solution action resulted in decreased flexural strength, however, it did not impact the compressive strength of mortars. A minor impact of chloride ions on the pH of the pore liquid was recorded, while the tests did not show any influence of sulphate ions. Furthermore, aggressive ion concentration decreased in deeper specimen slices. Specimen phase composition testing after chloride ion action indicated the presence of a small amount of Friedel’s salt, while regular sodium chloride crystals were identified in the microscopic image. The performance properties of mortars exposed to the action of aggressive solutions were maintained.

Protection Effectiveness of Concrete Surface Treating Materials

2013 ◽  
Vol 834-836 ◽  
pp. 749-754 ◽  
Author(s):  
Li Wei Teng ◽  
Ran Huang ◽  
Si Yu Zou ◽  
Hui Mi Hsu
Keyword(s):  
Compressive Strength ◽  
Taguchi Method ◽  
Concrete Surface ◽  
Strength Test ◽  
Influential Factors ◽  
Absorption Test ◽  
Permeability Test ◽  
Key Factors ◽  
Factors Influencing ◽  
Compressive Strength Test

This study was aimed to evaluate the protection effectiveness of various concrete surface treating materials. Four types of surface treating materials and six parameters were selected. Compressive strength test, absorption test and permeability test were performed. Taguchi method was adopted to identify the key factors influencing the protection effectiveness provided by the surface treatment. L16(81Î26) orthogonal array was chosen to reduce the number of experiments. The major sequentially influential factors are type of coating material, w/c ratio of concrete substrate and coating thickness.

Experimental Study on Improvement Mechanism of Silane Emulsion on Acid Rain Corrosion of Green Ecological Concrete

2020 ◽  
Vol 12 (6) ◽  
pp. 873-883
Author(s):  
Wei Xun Hu ◽  
Yao Zhuang Li ◽  
Hua Peng
Keyword(s):  
Compressive Strength ◽  
Service Life ◽  
Acid Rain ◽  
Concrete Structure ◽  
Test Group ◽  
Chloride Ion ◽  
Chloride Ions ◽  
Test Time ◽  
Ratio Test ◽  
Mixing Ratio

Concrete structure is vulnerable to acid rain corrosion, which affects the service life of the material, in the corrosive environment, and concrete structure will deteriorate because of the erosion of water/chloride ions. Therefore, waterproof treatment of concrete structure is needed to improve the durability of the structure. In this study, the green ecological concrete is taken as the research object. The concrete is mixed with a certain amount of silane emulsion to reduce the probability of corrosion of concrete due to moisture and chloride ions, thereby prolonging the service life of this kind of concrete. During the experiment, in order to further test the corrosion resistance of silane emulsion to this kind of concrete, different kinds of concrete were taken as test objects and divided into 3 test groups, namely, the original test group (ITE), the non silane emulsion test group (TWSE) and the optimal ratio test group (OT-SE). It is proved by experiments that the best proportion of concrete mixed with silane emulsion is 0.32 of water binder ratio, 18% of coal powder mixing ratio, 37% of gravel mixing ratio and 0.23% of proportion of silane emulsion. The above factors are applied to compressive strength test, and 30 days as test time, the compressive strength of concrete with fly ash is measured. In the experiment of anticorrosion, compared with the traditional concrete samples, the electrical flux of concrete mixed with silane emulsion decreased by 28.7% in 8 h, that is, chloride ion permeability decreased significantly.

Curing Effects on Air Permeability of Concrete

2011 ◽  
Vol 214 ◽  
pp. 602-606 ◽  
Author(s):  
Gladis Camarini
Keyword(s):  
Compressive Strength ◽  
Cement Hydration ◽  
Air Permeability ◽  
Strength Test ◽  
Hydrated Cement ◽  
Steam Curing ◽  
Compressive Strength Test ◽  
Concrete Quality ◽  
Blastfurnace Slag ◽  
Kinetics Of

The kinetics of cement hydration can be accelerated by steam curing and this kind of curing can be responsible for increasing concrete porosity, since a greater portion of non hydrated cement particles can be present. The increased porosity results can result in increased permeability. The aim of this work was to investigate the influence of curing on concrete quality by air permeability and compressive strength test. It was measured by means of a non steady state air permeameter. Concretes were produced with Portland cements containing 0%, 27% and 53% of ground granulated blastfurnace slag. The amount of slag in cement influenced concrete performance and steam curing increased air permeability of concrete.

scholarly journals Menentukan Kualitas Hasil Perbaikan Beton Bangunan Dermaga Dengan Metode Inspeksi Teknik

2017 ◽  
Vol 6 (1) ◽  
pp. 23-29
Author(s):  
Sulardi Sulardi
Keyword(s):  
Compressive Strength ◽  
Research Method ◽  
Design Method ◽  
Concrete Surface ◽  
Strength Test ◽  
Concrete Repair ◽  
Concrete Core ◽  
Surface Protection ◽  
Compressive Strength Test

The research objective was to provide an overview of the engineering inspection methods used in determine the quality of repair results and the quality of the results of concrete repair based on the results of concrete repair what has been done. The research method is carried out by engineering inspection methods which include visual tests and rebar test of concrete surface, compressive strength test with hammer test, test for concrete homogeneity with UPV test, test profometer concrete thickness blanket, cast drilled concrete core sampling, tensile test and concrete connection carbonation test of concrete surfaces with phenopthalein solution. The results of the research are chipping and grouting with specifications of microconcrete flowable material and repaired concrete surface protection with a thick mastic shield coating material specifications min. 300 micron DFT has been proven improve the strong quality of existing concrete by 69.40% from the compressive strength of the installed concrete design. Method Technical inspection, repair methods and specifications of the material used can be replicated for repairs damage and to determine the quality of similar repairs elsewhere.

scholarly journals Pengaruh Penggunaan Fly Ash dari Berbagai Sumber terhadap Sifat Kimia dan Sifat Fisika pada Semen Tipe I (OPC)

2020 ◽  
Vol 11 (2) ◽  
pp. 61-71
Author(s):  
Yulizar Yusuf ◽  
Vivin Firman Savitri ◽  
Hermansyah Aziz
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Physical Properties ◽  
Main Parameter ◽  
Strength Test ◽  
Type I ◽  
Cement Type ◽  
Compressive Strength Test ◽  
Cement Mixture

The aim of this study is to utilize fly ash from various sources on chemical and physical properties of cement type I (OPC). Utilization of fly ash can improve the strengthness of the cement. It can reduce the waste of fly ash by utilization into cement process. The procedure has been carried out on cement type I (OPC) with the addition of fly ash additives from various sources with concentration variations such as 10% and 20%. Utilization of fly ash as additives substance in cement works to improve the quality of cement. The main parameter in determining the quality of cement is determined by the compressive strength. The results of the compressive strength test showed that the addition of fly ash with a concentration of 10% had a higher effect on the compressive strength than the addition of a concentration of 20%. 5 types fly ash from various sources, fly ash from PT Sinar Mas gives greater compressive strength at 28 days. the addition of fly ash additives to OPC cement mixture has chemical and physical properties which are not much different from properties of PCC cement.

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