Study on Chloride Ion Permeability Resistance Variation of C40 Concrete

2014 ◽  
Vol 919-921 ◽  
pp. 1845-1848
Author(s):  
Zhi De Huang
Keyword(s):  
Concrete Structure ◽  
Chloride Ion ◽  
Construction Technology ◽  
Ion Permeability ◽  
Resistance Variation ◽  
Concrete Quality ◽  
Curing Condition

The influence of construction seasons and curing condition on chloride ion permeability of entity structure concrete was analyzed, which was based on the monitoring of pier concrete quality constructed seasonal of Qingdao bay bridge. At the same time, durability of entity concrete structure was analyzed combining site construction technology.

Test and Study on Green High-Performance Marine Concrete Containing Ultra-Fine Limestone Powder

2013 ◽  
Vol 368-370 ◽  
pp. 1112-1117
Author(s):  
Jin Hui Li ◽  
Liu Qing Tu ◽  
Ke Xin Liu ◽  
Yun Pang Jiao ◽  
Ming Qing Qin
Keyword(s):  
Fly Ash ◽  
High Performance ◽  
Mechanical Performance ◽  
Chloride Ion ◽  
Limestone Powder ◽  
Ion Permeability ◽  
High Quality ◽  
Cracking Resistance ◽  
Slag Powder ◽  
Marine Concrete

In order to solve the environment pollution of limestone powder during production of limestone manufactured sand and gravel and problem of lack of high quality fly ash or slag powder in ocean engineering, ultra-fine limestone powder was selected for preparation of green high-performance marine concrete containing fly ash and limestone powder and that containing slag powder and limestone powder for tests on workability, mechanical performance, thermal performance, shrinkage, and resistance to cracking and chloride ion permeability. And comparison was made between such green high-performance concrete and conventional marine concrete containing fly ash and slag powder. Moreover, the mechanism of green high-performance marine concrete was preliminary studied. Results showed that ultra-fine limestone powder with average particle size around 10μm had significant water reducing function and could improve early strength of concrete. C50 high-performance marine concrete prepared with 30% fly ash and 20% limestone powder or with 30% slag powder and 30% limestone powder required water less than 130kg/m3, and showed excellent workability with 28d compressive strength above 60MPa, 56d dry shrinkage rate below 300με, cracking resistance of grade V, 56d chloride ion diffusion coefficient not exceeding 2.5×10-12m2/s. Mechanical performance and resistance to chloride ion permeability of limestone powder marine concrete were quite equivalent to those of conventional marine concrete. But it had better workability, volume stability and cracking resistance. Moreover, it can serve as a solution to the lack of high quality fly ash and slag powder.

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.

Effects of Compositions on the Chloride Ion Permeability of Geopolymer Concrete

2012 ◽  
Vol 450-451 ◽  
pp. 428-432
Author(s):  
Qing Wang ◽  
Jing Da ◽  
Cun Bao Zhang ◽  
Zhao Yang Ding ◽  
Zhi Tong Sui
Keyword(s):  
Chloride Ion ◽  
Geopolymer Concrete ◽  
Ion Permeability

scholarly journals Effect of Lithium-Slag in the Performance of Slag Cement Mortar Based on Least-Squares Support Vector Machine Prediction

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1652 ◽  
Author(s):  
Jianghu Lu ◽  
Zhexuan Yu ◽  
Yuanzhe Zhu ◽  
Shaowen Huang ◽  
Qi Luo ◽  
...  
Keyword(s):  
Support Vector Machine ◽  
Compressive Strength ◽  
Least Squares ◽  
Cement Mortar ◽  
Chloride Ion ◽  
Industrial Wastes ◽  
Support Vector ◽  
Ion Permeability ◽  
Property Changes ◽  
Lithium Slag

There is a universally accepted view that environmental pollution should be controlled while improving cement mortar natural abilities. The purpose of this study is to develop a green cement mortar that has better compressive strength and anti-chloride ion permeability. Two industrial wastes, lithium-slag and slag, were added to cement mortar, and the role of lithium-slag was to activate slag. In addition, to save economic and time costs, this paper also used the least-squares support vector machine (LS-SVM) method to predict the property changes of cementitious-based materials. Then multiple natural abilities of samples, including compressive strength, anti-chloride ion permeability, and fluidity, were tested. In addition, LS-SVM and traditional support vector machine (SVM) were used to train and forecast the performance, including compressive strength. The results show that lithium-slag can activate slag to improve the compressive strength, anti-chloride ion permeability of mortar, and LS-SVM sharpens accuracy by 11% compared to SVM.

The Seismic Damage Characteristic and Mechanism Analysis of Building Structure in Wenchuan Earthquake

2011 ◽  
Vol 287-290 ◽  
pp. 1892-1895
Author(s):  
Yu Wang ◽  
Yong Yao ◽  
Bin Cheng ◽  
Lin Wang
Keyword(s):  
Concrete Structure ◽  
Resistance Mechanism ◽  
Structure Type ◽  
Seismic Damage ◽  
Construction Technology ◽  
Mechanism Analysis ◽  
Damage Degree ◽  
Feature Structure ◽  
Frame Construction ◽  
Damage Characteristic

In the paper, the seismic damage information of six kinds of buildings, including Brick and concrete structure, the bottom frame brick and concrete structure, frame construction, Big span structure, special structure, farmhouse, were collected. Based on the architecture type, damage degree, height of house, the seismic damage information were statistic analysis in the damage characteristic of the structure. And on the basis of the damage characteristic, the dynamic response and earthquake resistance mechanism were studied. The correlation among site feature, structure type, strength of materials, construction technology and the seismic damage of structure were discussed.

Study on the Corrosion Performance of Reinforced Concrete by Using the Seawater Hot Rain Testing Equipment

2013 ◽  
Vol 699 ◽  
pp. 173-178
Author(s):  
Yue Li ◽  
Zhong Wei Gu ◽  
Xian Ming Qin
Keyword(s):  
Reinforced Concrete ◽  
Marine Environment ◽  
Rust Resistance ◽  
Chloride Ion ◽  
Crystalline Material ◽  
Test Results ◽  
Ion Permeability ◽  
Corrosion Performance ◽  
Different Types ◽  
Rust Inhibitor

In order to investigate the corrosion performance of reinforced concrete in the marine environment, the seawater hot rain testing (SHRT) equipment was used to imitate the marine environment and accelerate corrosion rate by circularly spraying seawater to the samples under high temperatures which can attain 70°C. The test results show that SHRT can accelerate the chloride ion permeability which can quickly investigate the corrosion performance of reinforced concrete. Different types of material admixtures have different influences on the corrosion performance of reinforcement concrete, and rust inhibitor and cementitious capillary crystalline material can improve the anti-rust resistance of reinforced concrete effectively.

Effect of Metakaolin-Based Modifier on the Permeability of Concrete Structure in the Marine Environment

2013 ◽  
Vol 438-439 ◽  
pp. 117-120
Author(s):  
Jun Tao Ma ◽  
Liang Yan ◽  
Yu Ping Tong ◽  
Hui Xian Wang
Keyword(s):  
Fly Ash ◽  
Marine Environment ◽  
Concrete Structure ◽  
Chloride Ion ◽  
Penetration Resistance ◽  
Chloride Ion Penetration ◽  
Working Performance ◽  
Electric Flux ◽  
Penetration Behavior ◽  
Strength And Durability

Corrosion of the steel reinforcement in the concrete structure caused by chloride ion penetration becomes more serious in the marine environment. Metakaolin has been widely used in the concrete structure to improve the strength and durability. The combination of metakaolin (MK) and fine fly ash (FA) was studied in the article and the penetration behavior of concrete with various contents of metakaolin-based modifier is investigated. The penetration resistance of concrete was tested in combination of electric flux test. The improving mechanism was studied with mercury intrusion porosimetry analysis (MIP). The experiment results indicate that metakaolin-based modifier improved the penetration resistance of concrete obviously. The combination of fine fly ash weakened the water sucking action of metakaolin and preserved the working performance of concrete. The pore size distribution of concrete containing metakaolin-based modifier has been optimized to improve the microstructure and enhance the penetration resistance of concrete.

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