scholarly journals Investigation on Durability Behaviour and Optimization of Concrete with Triple-Admixtures Subjected to Freeze-Thaw Cycles in Salt Solution

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Xuejiao Li ◽  
Wensheng Wang ◽  
Zhiqing Zhu ◽  
Kunkun Zheng
Keyword(s):  
Salt Solution ◽  
Coupling Effect ◽  
Orthogonal Experiment ◽  
Cold Climate ◽  
Working Environment ◽  
Mineral Admixtures ◽  
Cement Concrete ◽  
Chloride Permeability ◽  
Freeze Thaw ◽  
Air Entrained Concrete

In the seasonal frozen area of northeast China, cement concrete is usually in a working environment of cold climate and chlorine erosion coupling effect. In general, with a reasonable addition of air entraining agent (AEA) and multimineral admixtures such as fly ash, blast furnace slag, and silica fume, the durability of cement concrete under the effects of freeze-thaw and salt solution can be significantly improved in cold regions. However, due to several more compositions of cement concrete with multiple mineral admixtures, it would take excessive trial mixtures to select the desired mixture proportion based on the conventional method. This means a great deal of costs of raw materials and laboratory experimental time. In this paper, the experimental scheme of mixture proportion for air-entrained concrete with multimineral admixtures was designed based on the orthogonal experiment design method. Based on the compressive strength, rapid chloride permeability, and weight loss and relative dynamic elastic modulus after salt freeze-thaw cycles, the influence of different mineral admixtures and their dosages on the durability of concrete subjected to freeze-thaw in salt solution was analyzed. After that, based on genetic algorithm, an optimization of mixture proportion was proposed, which only requires less trial mixes and accessible optimization process. The test results indicated the superiority of air-entrained concrete with multimineral admixtures when serving in salt freeze-thaw environment. Eventually, it was also verified that the optimized concrete in this paper could achieve pleasurable durability performances under salt freeze-thaw cycles.

scholarly journals SURFACE SCALING RESISTANCE OF CONCRETE MODIFIED WITH BITUMINOUS ADDITION

2004 ◽  
Vol 10 (1) ◽  
pp. 25-30
Author(s):  
Marta Kosior-Kazberuk ◽  
Walery Jezierski
Keyword(s):  
Construction Industry ◽  
Portland Cement Concrete ◽  
Nacl Solution ◽  
Cement Concrete ◽  
Freezing And Thawing ◽  
Freeze Thaw ◽  
Cold Environments ◽  
Surface Scaling ◽  
Air Entrained Concrete ◽  
Scaling Resistance

Deterioration of concrete due to surface scaling is a very serious durability problem faced by the construction industry in cold environments. The experimental results of resistance to scaling due to cyclic freezing and thawing in the presence of 3 % NaCl solution (de‐icing agent) of not air‐entrained concrete with and without bituminous addition are presented and discussed in the paper. The results have been analysed using the analysis of variance and regression to verify the effect of addition content, number of freeze‐thaw cycles and the sort of cement on concrete ability to scaling. The statistical analysis showed that the bituminous addition significantly improves the scaling resistance of Portland cement concrete.

scholarly journals Multi-scale computational modeling for concrete damage by mixed pore pressures – case of coupled alkali–silica reaction and cyclic freeze/thaw

2018 ◽  
Vol 35 (6) ◽  
pp. 2367-2385 ◽  
Author(s):  
Fuyuan Gong ◽  
Yuya Takahashi ◽  
Koichi Maekawa
Keyword(s):  
Coupling Effect ◽  
Mechanical Damage ◽  
Frost Damage ◽  
Alkali Silica Reaction ◽  
Content Type ◽  
Freeze Thaw ◽  
Multi Scale ◽  
Pore Pressures ◽  
Macro Scale ◽  
Air Entrained Concrete

Purpose This paper aims to propose a multi-scale simulation approach for the concrete macro-mechanical damage caused by mixed micro-pore pressures, such as the coupled alkali–silica reaction (ASR) and freeze-thaw cycles (FTC). Design/methodology/approach The micro-physical events are computationally modeled by considering the coupling effect between ASR gel and condensed water in the mixed pressure and motion. The pressures and transport of pore substances are also linked with the concrete matrix deformation at macro-scale through a poro-mechanical approach, and affect each other, reciprocally. Once the crack happens in the nonlinear analysis, both the micro-events (water and gel motion) and the macro mechanics will be mutually interacted. Finally, different sequences of combined ASR and FTC are simulated. Findings The multi-chemo mechanistic computation can reproduce complex events in pore structures, and further the macro-damages. The results show that ASR can reduce the FTC expansion for non-air-entrained concrete, but may increase the frost damage for air-entrained concrete. The simulation is examined to bring about the observed phenomena. Originality/value This paper numerically clarifies the strong linkage between macro-mechanical deformation and micro-chemo-physical events for concrete composites under coupled ASR and FTC.

scholarly journals Durability Evaluation of Concrete with Multiadmixtures under Salt Freeze-Thaw Cycles Based on Surface Resistivity

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Shibin Luo ◽  
Wei Liang ◽  
Hua Wang ◽  
Wensheng Wang ◽  
Rongjun Zou
Keyword(s):  
Flexural Strength ◽  
Concrete Strength ◽  
Air Entrainment ◽  
Surface Resistivity ◽  
Mineral Admixtures ◽  
Chloride Permeability ◽  
Freeze Thaw ◽  
Air Content ◽  
Rapid Chloride Permeability ◽  
Function Relationship

According to the climatic characteristics of seasonal frozen area in northeast China, the concrete strength tests, surface resistivity, rapid chloride permeability, and freeze-thaw test under salt solution were carried out to study the influences of mineral admixtures and air content on the conventional properties and salt freeze-thaw resistance of concretes. Then, the correlation analysis of surface resistivity with strength and rapid chloride permeability were further investigated. Subsequently, the changes of cumulative mass loss and relative dynamic elastic modulus varying with salt freeze-thaw cycles were analyzed to study the influences of mineral admixtures and air content on salt freeze-thaw resistance of concrete. The test results showed that fly ash (FA) was not conducive to improve the strength and salt freeze-thaw resistance of concrete. However, blast furnace slag (BFS) and silica fume (SF) could improve the compressive and flexural strength of concrete, in which SF can improve its strength more significantly. Increasing the air content of concrete will lead to the reduction of its compressive strength, and the flexural strength first increased and then decreased. Nevertheless, the addition of air-entrainment agent (AEA) has the best effect on improving the salt freeze-thaw resistance of concrete. Moreover, surface resistivity of concrete has a good exponential function relationship with strength and a good power function relationship with rapid chloride permeability. Therefore, it is of great significance for engineering quality control and quickly and nondestructive testing.

Study on Cement Concrete Pavement Treatment Methods of Common Damage Diseases

2014 ◽  
Vol 716-717 ◽  
pp. 307-309 ◽  
Author(s):  
Zhong Gen Liu ◽  
Fu Ming Xu ◽  
Guo Bin Cao
Keyword(s):  
Disease Prevention ◽  
Concrete Pavement ◽  
Jilin Province ◽  
Fracture Dislocation ◽  
Cement Concrete ◽  
Corner Crack ◽  
Treatment Methods ◽  
Pavement Maintenance ◽  
Freeze Thaw ◽  
Cement Concrete Pavement

This paper analyzed for common diseases treatment methods for cement pavement in Jilin province seasonal freeze-thaw area, based on the analyses, disease prevention and repair methods have been put forward for water deposit, fracture, dislocation, potholes, arch, plate corner crack and uneven settlement, the research results have certain reference meanings for cement pavement maintenance.

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.

Corrosion Resistance Performance of Ethylamines in Fly Ash Blended Cement Concrete

2014 ◽  
Vol 507 ◽  
pp. 286-290
Author(s):  
V. Rajkumar
Keyword(s):  
Corrosion Resistance ◽  
Fly Ash ◽  
Blended Cement ◽  
Impedance Measurement ◽  
Chloride Ions ◽  
Experimental Investigations ◽  
Optimal Dosage ◽  
Cement Concrete ◽  
Chloride Permeability ◽  
Resistance Performance

The main aim of this investigation is to study the influence of monoethylamine, diethylamine and triethylamine inhibitors on the corrosion resistance performance of 25% fly ash blended cement concrete. These inhibitors were added in dosages of 1%, 2%, 3% and 4% by weight of cement and experimental investigations have been carried out to compare the effectiveness of these three inhibitors with regard to strength and corrosion resistance. The mechanical strength properties studied were compressive, split tensile, flexural and bond strengths. The resistance to corrosion was evaluated based on the performance of the concrete for the penetration of chloride ions by means of impressed voltage technique, Rapid chloride permeability test (RCPT), AC impedance measurement, and weight loss measurement and ultimately the most effective of the three inhibitors and its optimal dosage has been determined.

Mineral Admixtures as Components of Cement Concrete

2021 ◽  
pp. 3-28
Author(s):  
Leonid Dvorkin ◽  
Vadim Zhitkovsky ◽  
Nataliya Lushnikova ◽  
Yuri Ribakov
Keyword(s):  
Mineral Admixtures ◽  
Cement Concrete
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