Study on the Influence of Painting Processes on the Protective Property of Concrete Coating

2012 ◽  
Vol 509 ◽  
pp. 88-92
Author(s):  
Yan Zheng ◽  
Qian Jin Mao ◽  
Ya Li Wang ◽  
Zi Ming Wang ◽  
Su Ping Cui
Keyword(s):  
Penetration Depth ◽  
Chloride Ion ◽  
Chloride Permeability ◽  
Acrylic Emulsion ◽  
Effective Measure ◽  
Water Based ◽  
Protective Performance ◽  
The Impact ◽  
The Relationship ◽  
Durability Of Concrete

With the development of construction project the durability of concrete is becoming more and more prominent, and surface coating is an effective measure to enhance the durability of concrete. Water-based silicone acrylic emulsion coating and water-based fluorocarbon resin coating were chose as prime and topcoat respectively. The impact of the coating’s thickness and viscosity on the durability of concrete and the relationship between the viscosity of the coating and its penetration depth were testified by chloride ion permeability-resistance property of concrete. The results show that thickness is proportional to the protective performance of the coating, and the penetration depth highly depends on viscosity. And the result of coating-4 viscosity method shows that samples with viscosity between 15 and 25 seconds have better chloride permeability resistance.

scholarly journals Influence of Steam Curing Method on the Performance of Concrete Containing a Large Portion of Mineral Admixtures

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Mengyuan Li ◽  
Qiang Wang ◽  
Jun Yang
Keyword(s):  
Chloride Ion ◽  
Mineral Admixtures ◽  
Strength Development ◽  
Steam Curing ◽  
Chloride Permeability ◽  
Curing Conditions ◽  
Volume Stability ◽  
Ettringite Formation ◽  
The Impact ◽  
Reaction Degree

A comparison was made between the impact of raising the thermostatic temperature and the impact of prolonging the thermostatic time on the performance of steam-cured concrete containing a large portion of fly ash (FA) or ground granulated blast furnace slag (GGBS) by analysing the form removal strength, chemically combined water content, reaction degree, strength development, chloride permeability, and volume stability. For the materials and test conditions reported in this study, raising the thermostatic temperature is more favourable for concrete containing FA, as indicated by the significantly higher form removal strength and the higher growth of reaction degree of FA compared with prolonging the thermostatic time. With an increase in the thermostatic temperature, the hydration degree of a binder containing FA or GGBS initially increases and subsequently decreases. Although concrete containing FA can obtain satisfactory form removal strength with steam curing at 80°C, the late strength development of concrete containing FA is slow for the same curing conditions. The effect of the late performance of resistance to chloride ion permeability improved by FA is better than the effect improved by GGBS. The risk of destroying the structure of concrete containing a large portion of FA or GGBS due to delayed ettringite formation (DEF) is minimal when specimens were steam-cured at 80°C.

scholarly journals The Durability of Concrete Modified by Waste Limestone Powder in the Chemically Aggressive Environment

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1693 ◽  
Author(s):  
Maja Kępniak ◽  
Piotr Woyciechowski ◽  
Paweł Łukowski ◽  
Justyna Kuziak ◽  
Rafał Kobyłka
Keyword(s):  
Negative Impact ◽  
Raw Materials ◽  
Desirability Function ◽  
Chloride Ion ◽  
Production Costs ◽  
Limestone Powder ◽  
Fine Aggregate ◽  
Concrete Technology ◽  
The Impact ◽  
Durability Of Concrete

The idea of sustainable development assumes that natural resources must be treated as limited goods and that waste must be managed rationally. This idea and the constant striving to reduce production costs make the use of waste materials as substitutes for traditionally used raw materials from non-renewable sources increasingly popular. In cement concrete technology, there are many possibilities to use waste as components of mortars and concretes. The subject of this paper is a fine-grained material, obtained as a by-product during the preparation of aggregate for mineral-asphalt mixtures. The aim of the research was to test the suitability of the selected type of powder, namely limestone powder, as a component of cement composites. The paper presents an evaluation of the potential of using the limestone powder as a substitute for the fine aggregate, focusing on the impact of such a modification on aspects of durability. The sulfate degradation and chloride ion diffusion in concrete were investigated. The overall desirability function has been determined. It was demonstrated that the satisfactory value of the general desirability can be attributed to most of the investigated concretes. Positive test results support the potential of replacing part of natural fine aggregate with the tested waste limestone dust without a negative impact on the durability of concrete.

Study on Corner Contact Shock of Gear Transmission by ADAMS Software

2015 ◽  
Vol 778 ◽  
pp. 205-211
Author(s):  
Li He ◽  
Jin Yuan Tang
Keyword(s):  
Penetration Depth ◽  
Impact Velocity ◽  
Impact Force ◽  
Ansys Software ◽  
New Approach ◽  
Adams Software ◽  
Simulation Results ◽  
The Impact ◽  
The Relationship ◽  
Key Parameter

Solving gear meshing impact force problems by using ADAMS software is studied.A pair of tooth meshing model is established based on UG, modal neutral file is generated by using ANSYS software, calculating gear meshing impact after Importing ADAMS. The relationship between the impact velocity and the impact force by taking reasonable key parameter about penetration depth in ADAMS simulation.A new approach for studying gear meshing impact is proposed here, and the simulation results show that ADAMS software is a very useful tool for solving gear corner contact shock problems outside the normal path of action line.

Effect of Aggregate Volume Fraction on the Charge Passed of Mortar and Concrete

2009 ◽  
Vol 405-406 ◽  
pp. 283-288 ◽  
Author(s):  
Quan Lin Niu ◽  
Chong Zhi Li
Keyword(s):  
Penetration Depth ◽  
Volume Fraction ◽  
Low Permeability ◽  
Chloride Permeability ◽  
Volume Fractions ◽  
Aggregate Fraction ◽  
Low Charge ◽  
Astm C1202 ◽  
The Relationship ◽  
Cl Permeability

Charge passed of mortars with different aggregate volume fractions was tested according to ASTM C1202, and the differential expression of the Ohm law was introduced to explain the relationship between charge passed data and aggregate fractions.Cl- penetration depth of the corresponding mortars and concretes was measured to illustrate the influence of the aggregate volume fraction on their chloride permeability. It was shown that the charge passed of mortar was negatively correlated with aggregate volume fractions, and high aggregate fraction bearing concrete with low charge passed did not necessarily mean low permeability. As a result, the influence of aggregate fraction on charge passed should be taken into consideration when charge passed data was employed to evaluate Cl- permeability of concrete.

scholarly journals Spatiotemporal Variations of Reference Evapotranspiration and Its Determining Climatic Factors in the Taihang Mountains, China

Water ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3145
Author(s):  
Tingting Kang ◽  
Zeng Li ◽  
Yanchun Gao
Keyword(s):  
Climate Change ◽  
Land Surface ◽  
Reference Evapotranspiration ◽  
Climatic Factors ◽  
Sunshine Duration ◽  
High Elevation ◽  
Lower Sensitivity ◽  
Effective Measure ◽  
The Impact ◽  
The Relationship

Reference evapotranspiration (ETo) is an effective measure of atmospheric water demand of the land surface. In-depth investigations of the relationship between ETo and primary climatic factors can facilitate the adaptable agriculture and optimize water management, especially in the ecologically fragile Taihang Mountains (THM). This work assessed the spatiotemporal dynamics of ETo and its driving climatic factors from 1973 to 2016 in THM. Results showed: (1) Annual ETo slightly increased during 1973–2016; relative humidity (RH) decreased more slowly, the temperature increased more rapidly, and wind speed (WS) decreased more rapidly at higher elevation than those at lower elevations; (2) two breakpoints occurred in ETo series at 1990 and 1997, and an “evaporation paradox” existed in 1973–1990; (3) ETo at higher elevations had greater sensitivity to changes in RH and lower sensitivity to changes in Tmax and WS. Sensitivity of ETo to minimum air temperature (Tmin) at middle elevations was lowest among three elevation bands; (4) RH and sunshine duration (SD) were the dominant climatic factors of ETo for most periods and stations. This study helps us understand the impact of climate change on ETo in mountainous areas and confirms reference evapotranspiration in high-elevation areas is particularly sensitive to climate change.

scholarly journals The Impact of PM10 Levels on Pedestrian Volume: Findings from Streets in Seoul, South Korea

2019 ◽  
Vol 16 (23) ◽  
pp. 4833 ◽  
Author(s):  
Juwon Chung ◽  
Seung-Nam Kim ◽  
Hyungkyoo Kim
Keyword(s):  
Public Health ◽  
Air Quality ◽  
Accurate Information ◽  
Atmospheric Conditions ◽  
Effective Measure ◽  
Walking Activity ◽  
Surrounding Areas ◽  
Pm 10 ◽  
The Impact ◽  
The Relationship

Although many studies have revealed that both air quality and walking activity are dominant contributors to public health, little is known about the relationship between them. Moreover, previous studies on this subject have given little consideration to the day-to-day atmospheric conditions and floating populations of surrounding areas even though most pedestrian count surveys are not conducted on a single day. Against this backdrop, using the 2015 Pedestrian Volume Survey data and quasi-real-time weather, air quality, and transit ridership data in Seoul, this study investigates the relationship between particulate matter (PM)10 and pedestrian street volumes empirically. The regression results suggest that PM10 concentration determines people’s intention to walk and affects the volume of street-level pedestrians. The three regression models, which adopted different spatial aggregation units of air quality, demonstrated that PM10 elasticity of pedestrian volume is the largest in the borough-level (the smallest spatial unit of air quality alert) model. This means that people react to the most accurate information they can access, implying that air quality information should be provided in smaller spatial units for public health. Thus, strengthening air quality warning standards of PM is an effective measure for enhancing public health.

The Durability Failure of Pre-Damaged Concrete Induced by Mechanical Load

2012 ◽  
Vol 594-597 ◽  
pp. 1061-1065
Author(s):  
Fang Zhi Zhu ◽  
Fu Xiang Jiang ◽  
Jun Shang ◽  
Zhong Hua Bi
Keyword(s):  
Chloride Ion ◽  
Load Level ◽  
Uniaxial Tensile ◽  
Chloride Diffusion Coefficient ◽  
Freezing And Thawing ◽  
Chloride Ion Penetration ◽  
Negative Effect ◽  
The Impact ◽  
Durability Of Concrete ◽  
Ion Penetration

Chloride ion penetration and freezing and thawing damage are the two main factors that affect the durability of concrete structures. Through the chloride ion penetration test and freezing and thawing test of concrete specimens after tensile and compressive loading, the influence of load-induced damage on the long-term durability of concrete was studied. The results showed that the apparent chloride diffusion coefficient of concrete increased by 6.4% and 34%, and the surface chloride concentration increased 10% and 40%, respectively, both of which showed the "negative effect" when the uniaxial tensile load level reached the 65% and 75% of the ultimate capacity. However, with the increasing uniaxial compressive load level, the impact on the frost resistance of concrete experienced a transformation from the "positive effect" to the "negative effect".

Research on Chloride Ion Diffusion of Concrete Water-Based Capillary Crystalline Waterproofer and its Penetration Depth by Using Electron Microscope

2013 ◽  
Vol 857 ◽  
pp. 27-34 ◽  
Author(s):  
Xin Xiao ◽  
Qi Sen Zhang ◽  
Xiao Ye Liang ◽  
Xiao Ning Zhang
Keyword(s):  
Diffusion Coefficient ◽  
Electron Microscope ◽  
Penetration Depth ◽  
Good Condition ◽  
Chloride Ion ◽  
Chloride Ions ◽  
Ion Diffusion ◽  
Strength Concrete ◽  
Water Based ◽  
Chloride Ion Diffusion

In order to improve the durability of concrete structure, studying reduction effect that water-based capillary crystalline waterproofer has on chloride ion diffusion coefficient in the concrete; analyse the inner microstructure of concrete by using electron microscope, and observe the penetration depth of waterproof agent in concrete directly. Research shows that: the water permeable crystalline waterproof agent can significantly reduce the diffusion coefficient of chloride ions in concrete, after concrete forms, the earlier brush waterproof agent, the longer it cure and its improving effect is more prominent after brushing waterproof agent , reduction rate of chloride ion diffusion coefficient in low strength concrete is higher than high-strength concrete;in good condition of water percolation, by detecting of electron microscope, it proved waterproofing agent can penetrate into internal concrete 6cm at least , the gel produced can be filled with pore and micro crack of concrete, so it can significantly improve the compactness of the whole structure.

A hybrid method for determining material properties from instrumented micro-indentation experiments

1994 ◽  
Vol 9 (5) ◽  
pp. 1314-1321 ◽  
Author(s):  
Y-M. Chen ◽  
A.W. Ruff ◽  
J.W. Dally
Keyword(s):  
Penetration Depth ◽  
Material Properties ◽  
Ofhc Copper ◽  
Material Constants ◽  
Computation Process ◽  
Indentation Experiment ◽  
Micrometer Scale ◽  
The Impact ◽  
The Relationship ◽  
Micro Indentation

The impact code EPIC was employed to study the relationship between the applied force and the penetration depth in a micrometer-scale indentation experiment with oxygen free high conductivity (OFHC) copper. EPIC is an elastic-plastic finite element code that uses a Lagrangian formulation and triangular mesh, which can accommodate large deformation without the need to remesh during the computation process. By fitting the force-penetration curves for a triangular indenter with second degree polynomials, it was demonstrated that the fit changed with two material constants in the constitutive equation. A systematic procedure for determining the material constants is described that is based on matching either the slope or the curvature of the force penetration depth curves from numerical simulation and experiments. It is concluded that material constants can be determined from indentation data obtained using pyramidal or spherical indenters as well as a flat-ended indenter.

scholarly journals Effect of steel fiber on impact resistance and durability of concrete containing nano-SiO2

2021 ◽  
Vol 10 (1) ◽  
pp. 504-517
Author(s):  
Peng Zhang ◽  
Hongsen Zhang ◽  
Guo Cui ◽  
Xiaodong Yue ◽  
Jinjun Guo ◽  
...  
Keyword(s):  
Impact Energy ◽  
Steel Fiber ◽  
Impact Resistance ◽  
Chloride Ion ◽  
Penetration Resistance ◽  
Freeze Thaw ◽  
Chloride Ion Penetration ◽  
The Impact ◽  
Durability Of Concrete ◽  
Ion Penetration

Abstract Impact drop weight tests, rapid chloride migration coefficient tests, single-sided freeze–thaw tests, and mechanical property tests were performed to investigate the effect of the steel fiber (SF) content on the impact resistance and durability of concrete containing nano-SiO2 (NS). A fixed NS content of 3% and six SF contents in a range of 0–2.5% by volume were used. The impact resistance was measured based on the number of blows (N1, N2) and the impact energy. The durability of concrete includes its freeze–thaw resistance and chloride ion penetration resistance, which were appraised by the chloride ion diffusion coefficient (CDC) and relative dynamic elastic modulus (RDM), respectively. The ductility ratio was used to predict the impact resistance of concrete containing NS with different SF contents, and a linear relation between this ratio and the impact energy (R 2 = 0.853) was found. The experimental results indicated that SF could greatly improve the impact resistance of concrete. The addition of 2.0% SF increased N1 and N2 by 106 and 169%, respectively. In addition, an appropriate SF content significantly improved the durability of the concrete, including its frost resistance (especially in the middle and late freezing–thawing cycles) and chloride ion penetration resistance. An SF content of 1.5% was the optimum, decreasing the CDC of nano-concrete by 17.1% and minimizing the RDM loss. Moreover, the 1.5% SF content increased the compressive strength of concrete containing NS by 18.5%, whereas an SF content of 2.0% increased the splitting tensile strength and flexural strength by 77 and 20%, respectively. Furthermore, when the SF content exceeded a certain value, the improvement effect on these properties began to decrease and even became negative.

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