scholarly journals Distribution Map of Frost Resistance for Cement-Based Materials Based on Pore Structure Change

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2509
Author(s):  
Nguyen Xuan Quy ◽  
Takumi Noguchi ◽  
Seunghyun Na ◽  
Jihoon Kim ◽  
Yukio Hama
Keyword(s):  
Prediction Model ◽  
Pore Structure ◽  
Frost Resistance ◽  
Frost Damage ◽  
Structure Change ◽  
Quantitative Prediction ◽  
Weather Data ◽  
Distribution Map ◽  
Cement Based Materials ◽  
Damage Risk

This paper presents a prediction method and mathematical model based on experimental results for the change in pore structure of cement-based materials due to environmental conditions. It focuses on frost damage risk to cement-based materials such as mortar. Mortar specimens are prepared using water, ordinary Portland cement, and sand and the pore structure is evaluated using mercury intrusion porosimetry. New formulas are proposed to describe the relationship between the pore structure change and the modified maturity and to predict the durability factor. A quantitative prediction model is established from a modified maturity function considering the influences of environmental factors like temperature and relative humidity. With this model, the frost resistance of cement-based materials can be predicted based on weather data. Using the prediction model and climate data, a new distribution map of frost damage risk is created. It is found that summer weather significantly affects frost resistance, owing to the change in pore structure of cement-based mortar. The model provides a valuable tool for predicting frost damage risk based on weather data and is significant for further research.

scholarly journals Investigation of thermal, moisture, and mechanical properties of wet and dry fired clay materials to assess frost damage risk

2019 ◽  
Vol 282 ◽  
pp. 02083
Author(s):  
Kazuma Fukui ◽  
Chiemi Iba ◽  
Madoka Taniguchi ◽  
Kouichi Takahashi ◽  
Daisuke Ogura
Keyword(s):  
Mechanical Properties ◽  
Environmental Conditions ◽  
Frost Resistance ◽  
Building Materials ◽  
Frost Damage ◽  
Thermal And Mechanical Properties ◽  
Freeze Thaw ◽  
Different Temperatures ◽  
Damage Risk ◽  
Clay Materials

Frost action is one of the main causes for deterioration of porous building materials under defined hygrothermal conditions. For an accurate assessment of the frost damage risk under various environmental conditions, thermal, moisture, and mechanical properties should be considered; the hygrothermal properties affect the distribution of temperature and amount of frozen water in the material, whereas the mechanical properties are necessary to predict deformation and damage. Moreover, the dependency of these properties on the moisture content should be understood. Therefore, in this study, thermal, moisture, and mechanical properties of wet and dry fired clay materials were measured. The fired clay materials were sintered at two different temperatures, 1000 °C and 1100 °C (samples T10 and T11, respectively) for comparison. The measured thermal and mechanical properties are considerably different in the wet state compared to the dry state. Freeze–thaw tests were conducted to investigate the relation between the material properties and the frost resistance under a simple experimental condition. As expected, based on the pore structure and obtained mechanical properties, T10 exhibited lower frost resistance than T11 in the freeze–thaw test. Finally, frost damage risk was assessed under various environmental conditions based on the obtained hygrothermal and mechanical properties.

scholarly journals Life Prediction Model of Mineral Admixture Cement Based-Materials under Early Age CO2-Erosion

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 413
Author(s):  
Saisai Wang ◽  
Jian Chen ◽  
Xiaodong Wen
Keyword(s):  
Prediction Model ◽  
Life Prediction ◽  
Experimental Tests ◽  
Mineral Admixture ◽  
Model Parameters ◽  
Influence Coefficient ◽  
Test Pieces ◽  
Cement Based Materials ◽  
Particle Group ◽  
Life Prediction Model

Most of the existing models of structural life prediction in early carbonized environment are based on accelerated erosion after standard 28 days of cement-based materials, while cement-based materials in actual engineering are often exposed to air too early. These result in large predictions of the life expectancy of mineral-admixture cement-based materials under early CO2-erosion and affecting the safe use of structures. To this end, different types of mineral doped cement-based material test pieces are formed, and early CO2-erosion experimental tests are carried out. On the basis of the analysis of the existing model, the influence coefficient of CO2-erosion of the mineral admixture Km is introduced, the relevant function is given, and the life prediction model of the mineral admixture cement-based material under the early CO2-erosion is established and the model parameters are determined by using the particle group algorithm (PSO). It has good engineering applicability and guiding significance.

Expansion strain model and damage risk control for cement-based materials with low water–binder ratios under rehydration

2021 ◽  
Vol 287 ◽  
pp. 122996
Author(s):  
Yazhou Liu ◽  
Mingzhe An ◽  
Ge Zhang ◽  
Ziruo Yu ◽  
Yue Wang ◽  
...  
Keyword(s):  
Risk Control ◽  
Cement Based Materials ◽  
Strain Model ◽  
Damage Risk

Field survey on frost damage to roof tiles under climatic conditions

2016 ◽  
Vol 34 (2) ◽  
pp. 135-149 ◽  
Author(s):  
Chiemi Iba ◽  
Ayumi Ueda ◽  
Shuichi Hokoi
Keyword(s):  
Field Survey ◽  
Winter Season ◽  
Frost Damage ◽  
Climatic Conditions ◽  
Weather Data ◽  
Measured Temperature ◽  
Content Type ◽  
Roof Tile ◽  
Deterioration Process ◽  
The Impact

Purpose – Frost damage is well-known as the main cause of roof tile deterioration. The purpose of this paper is to develop an analytical model for predicting the deterioration process under certain climatic conditions. This paper describes the results of a field survey conducted to acquire fundamental information useful to this aim. Design/methodology/approach – A field survey of roof tile damage by freezing was conducted in an old temple precinct in Kyoto, Japan. Using detailed observations and photographic recordings, the damage progress was clarified. To examine the impact of climatic conditions upon the damage characteristics, weather data and roof tile temperatures were measured and logged in the winter season. Findings – The deterioration process was observed under the climatic conditions associated with the measured temperature of the roof tiles. In particular, it was revealed that the orientation has a significant influence on increasing or decreasing the risk of frost damage. For certain distinctive forms of damage, the deterioration mechanisms were estimated from the viewpoint of the moisture flow and temperature distribution in the tile. Originality/value – This study contributes to the elucidation of the mechanism behind frost damage to roof tiles. The findings will guide the construction of a numerical model for frost damage prediction.

Influence of Lightweight Aggregate on Durability of High Performance Concrete

2009 ◽  
Vol 405-406 ◽  
pp. 197-203
Author(s):  
Bao Sheng Zhang ◽  
Li Juan Kong ◽  
Yong Ge
Keyword(s):  
Pore Structure ◽  
Cement Paste ◽  
Frost Resistance ◽  
High Performance ◽  
High Performance Concrete ◽  
Bound Water ◽  
Lightweight Aggregate ◽  
Normal Weight ◽  
Lightweight Aggregate Concrete ◽  
Aggregate Concrete

High performance concrete (HPC) with a water/cement ratio (w/c) of 0.32 and different lightweight aggregate (LWA) contents (0%, 25%, 50%, 75%, 100%) were prepared, and the influence of LWA on concrete frost-resistance and impermeability at different ages were studied, as well as the hydration degree, hydrated product, pattern and pore structure of the paste around aggregate. The results show that, by replacing normal weight aggregate (NWA) with 50% and 100% volume contents of pre-wetted LWA respectively, the chemical bound water of the cement paste surrounding aggregate are increased 12.1% and 22.7% as compared to concrete mixed without LWA. And at 28 days, lightweight aggregate concrete has the highest Ca(OH)2 content, whereas the 90-day Ca(OH)2 content of normal weight concrete is the highest. This proves that, with the increase of LWA content in concrete, both of the internal curing effect of pre-wetted LWA and secondary hydration effect of fly ash (FA) are strengthened, this can also be verified by the SEM study. Furthermore, the pore structure of the cement paste around aggregate can be improved consequently. The performance of frost-resistance of HPC can be improved by mixing LWA, the 90 day-frost-resistance of lightweight aggregate concrete is about 2.5 times of that of concrete mixed without LWA. The influence of LWA on the impermeability of HPC is different from normal concrete. When LWA content is more than 50%, the HPC impermeability decreased obviously, however at later age the difference between them becomes minor.

Effect of Saturation Degree on Concrete Deterioration due to Freeze-Thaw Action

2011 ◽  
Vol 477 ◽  
pp. 404-408 ◽  
Author(s):  
Wen Cui Yang ◽  
Yong Ge ◽  
Bao Sheng Zhang ◽  
Jie Yuan
Keyword(s):  
Frost Resistance ◽  
Water Pressure ◽  
High Water ◽  
Frost Damage ◽  
Critical Value ◽  
Cold Weather ◽  
Saturation Degree ◽  
Freeze Thaw ◽  
Air Content ◽  
The Difference

Freezing-thawing durability of cement concrete is extremely important in cold weather, to better understand mechanism of frost damage and air-entraining，saturation degree of pores in concrete and its relation with frost resistance were studied in this paper. Concrete specimens with different saturation degree from 0 to 100% were prepared used a sealed tin with a high water pressure pump. Then these specimens were subjected to six freezing-thawing cycles and the relative dynamic modulus of elasticity was examined. The results showed that critical saturation degree of concrete with water- binder ratio of 0.30 and 0.47, air content of 1%, 4% and 6% were from 0.60 to 0.80. When its saturation degree exceeded the critical value, concrete was deteriorated significantly after only six freeze-thaw cycles. The critical saturation degree was mainly related to the air content of concrete mixture, and it decreased with the increasing of air content. The difference between the saturation degree and the critical value can be used to evaluate potential frost resistance of concrete, and its result was consistent with the result of frost tests very well.

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