PERFORMANCE OF STEEL MICRO FIBER REINFORCED MORTAR MIXTURES CONTAINING PLAIN, BINARY AND TERNARY CEMENTITIOUS SYSTEMS

2016 ◽  
Vol 11 (4) ◽  
pp. 109-130 ◽  
Author(s):  
Ali Mardani-Aghabaglou ◽  
Cihat Yüksel ◽  
Hojjat Hosseinnezhad ◽  
Kambiz Ramyar
Keyword(s):  
Total Mass ◽  
Drying Shrinkage ◽  
Chloride Ion ◽  
Mineral Admixtures ◽  
Impact Loads ◽  
Test Results ◽  
Chloride Ion Penetration ◽  
Micro Cracks ◽  
The Matrix ◽  
Cementitious Systems

Steel micro fibers provide strengthening, toughening and durability improvement mechanisms in cementitious composites. However, there is not much data in the literature regarding how the extent of their effectiveness changes depending on the type of matrix being reinforced. For clarifying this point, the influence of a constant volumetric ratio (1%) of 6 mm long steel micro fibers on the performance of 5 mortar mixtures was investigated and were prepared using plain, binary and ternary cementitious systems. A total of 10 mixtures were cast. The mineral admixtures used in the study include silica fume (SF), metakaolin (MK) and a Class C fly ash (FA). While the replacement levels of SF and MK were 10% by weight of the total mass of the binder, this ratio was chosen as 30% for FA. In addition to the behavior of the mixtures under compressive, flexural and impact loads, abrasion, water absorption, chloride ion penetration, freezing-thawing resistance and drying shrinkage characteristics of the mixtures were determined. Test results indicate that generally the refinement in the pore structure of the matrix provided by mineral admixtures and the increase in resistance against growth and coalescence of micro-cracks provided by fibers produce a synergistic effect and improve the investigated performances of the mixtures.

Ultra-Low Cement Dosage Hill Sand Concrete’s Electric Flux and Carbonization Performance Study

2014 ◽  
Vol 584-586 ◽  
pp. 1332-1336
Author(s):  
Wei Wei Hu ◽  
Li Bin Xu ◽  
Yi Dong ◽  
Xiao Peng Nie
Keyword(s):  
Materials Science ◽  
Chloride Ion ◽  
Social Stability ◽  
Concrete Durability ◽  
Test Results ◽  
Performance Study ◽  
Chloride Ion Penetration ◽  
Concrete Materials ◽  
Electric Flux ◽  
Low Dosage

Concrete durability is closely related to the national economy and social stability, environmental protection, sustainable development is a major research topic concrete materials science, engineering and technological problems are a major concern. This paper studies resistance to chloride Ion penetration performance and anti-carbonation of low cement concrete sand hill. And combined with the test results analysis and discussion the low dosage of cement to sand concrete electric flux and the influence of carbonization resistance.

The Experimental Research on the Anti-Corrosion Performance of Concrete with Different Mineral Admixtures under Sulfate and Chloride Environment

2014 ◽  
Vol 638-640 ◽  
pp. 1431-1435
Author(s):  
Wen Xun Qian ◽  
Yan Chi Zhang ◽  
Xun Jie Chen ◽  
You Lin Ouyang
Keyword(s):  
Loss Rate ◽  
Chloride Ion ◽  
Strength Loss ◽  
Sulfate Attack ◽  
Mineral Admixtures ◽  
Corrosion Performance ◽  
Chloride Ion Penetration ◽  
Initial Stage ◽  
Chloride Environment ◽  
Permeability Of Chloride Ion

The performance of resistance to sulfate attack and permeability of chloride ion on concrete with different mineral admixtures (fly ash, slag single or both adding) under sulfate and chloride environment were discussed. The results indicated the performance of resistance to salt attack on concrete with appropriate mineral admixtures was improved. Under chloride environment, the resistance to sulfate attack coefficient of testing mortars descended, and compressive strength loss rate of concrete was raised after dry-wet cycles. Therefore, the performance of resistance to salt attack on concrete was decreased in this environment. Besides, on the initial stage of corrosion, the ability to resist chloride ion penetration of concrete was improved under sulfate environment, while the penetrating of chloride ion was accelerated on the later stage.

Durability Assessment of Hot Dip Galvanized Reinforcement Concrete

2010 ◽  
Vol 177 ◽  
pp. 533-536
Author(s):  
Quan Jiang ◽  
Yu Jun Liu ◽  
Ru Ping Liu
Keyword(s):  
Chloride Ion ◽  
Concrete Specimen ◽  
Test Results ◽  
Tidal Zone ◽  
Accelerated Corrosion ◽  
Protection Efficiency ◽  
Chloride Ion Penetration ◽  
Steel Bars ◽  
Durability Assessment ◽  
Accelerated Corrosion Test

Treat the steel bars by hot dip galvanizing technology to prepare steel concrete specimen. Adopt artificial accelerated corrosion test to simulate the seawater corrosive environment in continuous immersion zone and tidal zone and carry out accelerated corrosion for the concrete bars. Add NaCl whose cement content is 1%, 5% and 7% respectively in the concrete specimen to improve the chloride ion content in the system and simulate the strong corrosion environment. This thesis examines the corrosion influence of chloride ion penetration on the ordinary bars and hot-dip steel bars. It also assesses the corrosion protection efficiency for hot dip galvanized reinforcement (HDGR) by half cell method and analyzes the test results.

Influence of Mineral Admixtures on the Performance of Polymer Modified Porous Concrete

2009 ◽  
Vol 87-88 ◽  
pp. 92-97 ◽  
Author(s):  
Fang Xu ◽  
Ming Kai Zhou ◽  
Wei Guo Shen ◽  
Bei Xing Li
Keyword(s):  
Functional Performance ◽  
Element Model ◽  
Structural Features ◽  
Resistance Coefficient ◽  
Mineral Admixtures ◽  
Test Results ◽  
Strength Performance ◽  
Porous Concrete ◽  
Optimum Dosage ◽  
Micro Cracks

In order to improve the performance of polymer modified porous concrete (PMPC), the mineral admixtures (MAs) including fly ash (FA) and silicon fume (SF), are added in the concrete. In this paper, the optimum dosage of the MAs, the influence of the MAs on the strength performance, permeability performance and the surface functional performance of PMPC are studied. The microscopic test of SEM is used to explore the microscopic structure of PMPC. The test results indicate that: the dosage of 10% FA or of 6% SF is the optimum dosage, while the 28d compressive strength can reach 24MPa and 43MPa, respectively, the 28d flexural strength can reach 5.2MPa and 5.3MPa, respectively, and the permeability coefficient can reach 0.36cm/s and 0.32cm/s, respectively. The surface structural depth can reach more than 1mm and the slide resistance coefficient can reach more than 40BPN, which can conform to the standard of JTG F30-2003. The Contact Element Model is proved to conform to the structural features of PMPC. With the microscopic test, as the addition of the polymer and MAs, the internal micro-cracks and non-hydrated cement particles in the interfacial transition zone (ITZ) are covered by the cement paste and polymer films. The contact area, the mechanical property and durability of PMPC can be improved.

scholarly journals Effect of SiO2 Sol/Silane Emulsion in Reducing Water and Chloride Ion Penetration in Concrete

Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 682
Author(s):  
Yongjuan Geng ◽  
Shaochun Li ◽  
Dongshuai Hou ◽  
Xu Chen ◽  
Zuquan Jin
Keyword(s):  
Contact Angle ◽  
Hydrophobic Effect ◽  
Chloride Ion ◽  
Treatment Method ◽  
Chloride Diffusion ◽  
Capillary Absorption ◽  
Test Results ◽  
Ion Diffusion ◽  
Chloride Ion Penetration ◽  
Hydrophobic Treatment

Here, a new concrete hydrophobic treatment method is developed using SiO2 sol and silane emulsion. The effectiveness of the modification for concrete protection is evaluated through testing water absorption and chloride diffusion. Two types of concrete with different strength grades (C40, C50) are used as the research object. The results show that the water capillary absorption coefficient and chloride ion diffusion coefficient of concrete decrease greatly under the protection of SiO2 sol and silane emulsion. Additionally, the protection effect is better with the increase of SiO2 consumption. Contact angle test results reveal that when the coating amount of SiO2 sol and silane emulsion is 300 g/m2, respectively, the contact angle reaches 150.2°, indicating the concrete (C40) surface reaches the superhydrophobic state. Through scanning electron microscope (SEM) observation, it is found that the hydrophobic effect of the SiO2 sol/silane emulsion is mainly due to the change in the surface morphology of concrete (C40).

Properties of VA/E/MMA Terpolymer Powder-Modified Mortars

2015 ◽  
Vol 1129 ◽  
pp. 169-176
Author(s):  
Sunhee Hong ◽  
Wan Ki Kim
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Cement Mortar ◽  
Mercury Porosimetry ◽  
Chloride Ion ◽  
Test Results ◽  
Polymer Powder ◽  
Chloride Ion Penetration ◽  
Redispersible Polymer Powder

This study is to examine and clarify the quality of polymer-modified mortars using a VA/E/MMA terpolymer powder as compared with polymer-modified mortars using a VAE copolymer powder. Polymer-modified mortars using general commercial redispersible polymer powders are prepared with various polymer-cement ratios, and tested for flexural and compressive strengths, tensile strength, water absorption, chloride ion penetration, carbonation and pore size distribution by mercury porosimetry. Overall, the properties of polymer-modified mortars using a VA/E/MMA terpolymer powder were superior to those of polymer-modified mortars using a VAE copolymer powder. And VA/E/MMA terpolymer powder-modified mortars showed significantly improved mechanical properties and durability in comparison with unmodified mortar. It is concluded from the test results that the modification of cement mortar with redispersible polymer powder improves the properties of unmodified mortar, and VA/E/MMA terpolymer powder has higher quality than VAE copolymer powder.

A Method on the Rapid Assessment of Resistance to Chloride Ion Penetration for Mortar and Concrete with Mineral Admixtures

2004 ◽  
Vol 16 (4) ◽  
pp. 485-492 ◽  
Author(s):  
Jung-Jun Park ◽  
Sung-Wook Kim ◽  
Kyung-Taek Koh ◽  
Jong-Suk Lee ◽  
Jang-Hwa Lee
Keyword(s):  
Rapid Assessment ◽  
Chloride Ion ◽  
Mineral Admixtures ◽  
Chloride Ion Penetration ◽  
Ion Penetration

Effects of Mineral Admixtures on Carbonation and Chloride Ingress of Concrete

2012 ◽  
Vol 212-213 ◽  
pp. 878-882 ◽  
Author(s):  
Abuduhelili Haibier ◽  
Yong Xin Wu
Keyword(s):  
Concrete Structures ◽  
Steel Corrosion ◽  
Chloride Ion ◽  
Chloride Penetration ◽  
Mineral Admixture ◽  
Mineral Admixtures ◽  
Chloride Ingress ◽  
Test Results ◽  
Concrete Carbonation ◽  
Carbonation Process

Reinforcement corrosion is one important factor affecting the durability and safety of reinforced concrete structures. Concrete carbonation and chloride ion penetration is the main cause leading to steel corrosion, also important indicators affecting the service life of concrete structures. An accelerated carbonation experiment and Chloride penetration experiment was carried out on ordinary Portland cement (OPC) concrete and admixture concrete in various conditions. Eight concrete specimens of different mixture properties were tested in experiment. Resistance of OPC concrete system with and without mineral admixture (fly ash, slag) and air-entraining agent against carbonation was investigated. Besides, the influence of mineral admixture on the chloride penetration was also studied. The carbonation process and the factors affecting concrete carbonation are discussed according to test results. The test results were presented and they were in good agreement with the results of previous research.

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