Freeze-thaw Resistance Of Concrete Research Articles

Effect of nano‐silica on the mechanical performance and porosity evolution of concrete under freezing and thawing cycles

AbstractThe enhancement of freeze–thaw resistance in concrete is crucial for improving the durability and longevity of infrastructure in cold regions. Although the benefits of nano‐silica (NS) on concrete's freeze–thaw resistance have been demonstrated, there is still controversy surrounding the optimal concentration of admixture and underlying mechanisms. In this study, the mechanical performance (mass weight, elastic modulus, compressive and splitting strength) and porosity evolution (total porosity, porosity distribution and micro‐surface morphologies) of control concrete and concrete modified with five different NS admixture concentration (1%–5%) were tested under freezing and thawing (F–T) cycles, and damage models were established to assess the correlations between macroscopic and microscopic damages. The results indicate that F–T cycles lead to both damage in mechanic properties and porosity in concrete specimens. The effects of NS particles on macroscopic and microscopic damage under F–T conditions depend on their admixture concentration. A 2% concentration mitigates while a 5% dosage promotes both macroscopic and microscopic damages during F–T cycles. These differences can primarily be attributed to different dispersion status of NS particles in concrete, leading to variations in porosity evolution during F–T cycles. The macroscopic damage exhibit stronger correlation with microscopic damage factor modified by proportion of large pores compared to that only based on total porosity, suggest that the microscopic damage, especially large pores' proportion, contribute to macroscopic damage of concrete specimens under F–T cycles. These findings provide valuable references for field concrete engineering applications in cold areas.

Freeze-thaw Resistance of Concrete using Ground Granulated Blast-furnace Slag and Blast-furnace Slag Sand in Salt Water

Freeze-thaw Resistance of Concrete using Ground Granulated Blast-furnace Slag and Blast-furnace Slag Sand in Salt Water

Study on the Freeze-Thaw Resistance of Concrete Pavements in Seasonally Frozen Regions.

In seasonally frozen regions, concrete pavement is exposed to cycles of freeze-thaw and erosion from de-icing salt, which can lead to unfavorable service conditions and vulnerability to damage. This paper examines the compressive strength, flexural-tensile strength, abrasion resistance, permeability, and spacing factor of concrete, taking into account the impact of various curing conditions, de-icing salt solutions, and mass fractions on the concrete's freeze-thaw resistance. Two test methods, the single-face method and the fast-freezing method, were used to comparatively analyze the freeze-thaw resistance of concrete. The analysis was based on the surface scaling, water absorption rate, mass loss rate, relative dynamic elastic modulus, and relative durability index. The results indicate that the presence of salt solution significantly worsened the degree of concrete damage caused by freeze-thaw cycles. The use of freeze-thaw media, specifically sodium chloride (NaCl), calcium chloride (CaCl2), and potassium acetate (KAc) at mass fractions of 5%, 4.74%, and 5%, respectively, had the greatest impact on the surface scaling of concrete. However, their effect on the water absorption rate was inconsistent. When the freeze-thaw medium was water, the concrete's relative dynamic elastic modulus and relative durability index were 9.6% and 75.3% higher, respectively, for concrete cured in 20 °C-95% RH conditions compared to those cured in 0 °C-50% RH conditions. We propose a comprehensive relative durability index (DFw) by combining the results of two methods of freeze-thaw tests. The DFw of concrete cured in 0 °C-50% RH conditions was 83.8% lower than that of concrete cured in 20 °C-95% RH conditions when exposed to a freeze-thaw medium of 5% mass fraction NaCl solution. To evaluate the salt freeze-thaw resistance of concrete pavement, it is recommended to use surface scaling and DFw together.

Analysis and prediction of freeze-thaw resistance of concrete based on machine learning

Based on Support Vector Regression, Random Forest Regression, Gradient Boosting and Extreme Gradient Boosting, a prediction model of concrete's freeze-thaw mass loss rate with high accuracy and strong generalization ability is established. The impacts of water, cement, fly ash, slag, sand, natural coarse aggregate, recycled coarse aggregate, superplasticizer, air-entraining agent, and the number freeze-thaw cycles on the freeze-thaw resistance of concrete are systematically analyzed using feature importance analysis, global interpretation and partial dependence analysis. The main results are as follows: (1) The Gradient Boosting and Extreme Gradient Boosting models demonstrate relatively higher prediction accuracy, with the Extreme Gradient Boosting model exhibiting stronger generalization ability compared to the Gradient Boosting model. (2) Sand, natural coarse aggregate and the number freeze-thaw cycles have the most substantial impact on the freeze-thaw resistance of concrete, while the impact of recycled coarse aggregate is relatively modest. Utilizing suitable quantities of air-entraining agent, fly ash, slag, and superplasticizer can improve concrete's freeze-thaw resistance. (3) A reduced water-cement ratio is advantageous for enhancing concrete's resistance to freeze-thaw damage in cold regions. (4) The partial dependence analysis of Extreme Gradient Boosting model can provide references for optimizing the composition of each component during the preparation of concrete in cold regions. (5) A graphical user interface based on the Extreme Gradient Boosting model for predicting concrete freeze-thaw mass loss rate has been developed, facilitating user-friendly interaction with the computer program and enhancing the practicality of the model.

Evaluation of the compressive-strength reducing behavior of concrete containing rubber aggregate

It is well known that the toughness and freeze-thaw resistance of concrete can be improved by rubber aggregate (RA) while it significantly reduces the compressive strength. In this study, a simple semi-empirical prediction model of strength reduction factor (SRF) for rubberized concrete (RuC) is proposed to evaluate the compressive-strength reducing behavior of RuC. The model takes the volume fraction of RA as an independent variable and can be used to quantitatively describe the influence of different composition factors on compressive strength. In addition, a database containing more than 321 groups of reported experimental results is established to validate the proposed model. The main influencing factors of SRF are also clarified, including the content, particle size, surface property and replacement method of RA. According to the above factors, scientific classification and statistical fitting analysis are carried out on the database to determine the model parameter b. It is found that the proposed SRF model has good universality and predictability, which can be used to guide the mix design of RuC.

Farklı Agregalarla Üretilen Silindirle Sıkıştırılmış Betonların Donma-Çözülme Direncinin Araştırılması

Roller compacted concretes are a building material that can be produced using the raw materials used in traditional concrete production, which allows working with dry mix with the production technique, and is preferred for use in road and dam constructions. In this experimental study, the effect of using different aggregates in roller compacted concretes on the freeze-thaw resistance of concrete was investigated. Dolomite, basalt, marble and limestone were used as coarse aggregates in the production of roller compacted concrete. In roller compacted concrete production, concrete mixtures with zero slump value and water/cement ratio of 0.35 were prepared, and these mixtures were compressed in two stages and placed in the mold. The specimens were demolded 24 h after casting and moist-cured. The water-saturated cube specimens, which were kept in lime-saturated water for 90 days, were subjected to repeated freeze-thaw cycles of 12 hours at +20°C and 12 hours at -20°C. At the end of 25, 50 and 75 cycles, the weight and ultrasonic pulse velocity (UPV) of roller compacted concrete specimens were recorded. At the end of 75 cycles, the average compressive strength, standard deviation and coefficient of variation values of the specimens were determined. At the end of 75 freeze-thaw cycles, the compressive strength loss was determined as 12.2% in the samples produced with dolomite aggregate, 13.8% in those produced with basalt, 3.3% in those produced with marble, and 4.6% in those produced with limestone. As a result of the experimental study, it was observed that the aggregate type was effective on the freeze-thaw resistance of the roller compacted concretes.

Effects of Thermal Conductive Materials on the Freeze-Thaw Resistance of Concrete.

To solve the problem of black ice, many studies are being carried out. The key in recent days is enhancing the thermal conductivity of concrete. In this study, to improve the thermal conductivity, silicon carbide was used to substitute 50% and 100% of the fine aggregate. In addition, steel fiber is not only for enhancing the mechanical properties but could enhance thermal conductive material. Hence, the arched-type steel fiber was used up to a 1% volume fraction in this study. Furthermore, graphite was used for 5% of the volume fraction for enhancing the thermal conductivity. However, thermal damage would occur due to the difference in thermal conductivity between materials. Therefore, the thermal durability must be verified first. The target application of the concrete in this study was its use as road paving material. To evaluate the thermal durability, freeze–thaw and rapid cyclic thermal attacks were performed. The thermal conductivity of the specimens was increased with the increase in thermal conductive materials. Graphite has already been reported to have a negative effect on mechanical properties, and the results showed that this was the case. However, the steel fiber compensated for the negative effect of graphite, and the silicon carbide provided a filler effect. Graphite also had a negative effect on the freeze–thaw and rapid cyclic thermal attack, but the steel fiber compensated for the reduction in thermal durability. The silicon carbide also helped to improve the thermal durability in the same way as steel fiber. Comprehensively, the steel fiber enhanced all of the properties of the tests. Using 100% silicon carbide was considered the acceptable range, but 50% of silicon carbide was the best. Graphite decreased all the properties except for the thermal conductivity. Therefore, the content of graphite or using other conductive materials used should be carefully considered in further studies.

Freeze-thaw resistance of concrete containing mixed aggregate and construction and demolition waste-additioned cement in water and de-icing salts

Durability is a key property in concrete structures exposed to freeze–thaw cycles, particularly where the concrete mix includes recycled materials. This study explores 25% or 50% replacement of natural with mixed recycled aggregate (MRA) from construction and demolition waste (CDW), in concrete mixes prepared with recycled cement (including 25% fired clay-based waste and called OPC-CDW) or with ordinary Portland cement (OPC) and its effect on structural concrete resistance to freeze–thaw cycles (exposure classes XF1 to XF4). The findings show that the inclusion of MRA and OPC-CDW affect the material differently depending on the type of exposure. In concrete exposed to water, MRA induce a decline in load capacity, whereas OPC-CDW raised strength. The opposite was observed in concrete in contact with de-icing salts. The recycled concrete designed, proved to resist freeze–thaw cycles conducted in water (XF1 and XF3), whilst the presence of de-icing salts (XF2 and XF4) compromised their durability. In such cases additional measures would be needed for in the design and construction of structures built with recycled concrete.

Non-traditional Approach to the Evaluation of the Freeze-thaw Resistance of Concrete based on the Fracture Tests

The paper deals with a pilot study focused on the freeze-thaw (F-T) resistance of concrete. A non-traditional approach to the evaluation of the F-T resistance of concrete based on the determination of the fracture parameters is presented in the paper. Three types of specimens were used in the experimental program – prisms with edge and Chevron notch, and cylinders with the Chevron notch. Three sets of specimens of each shape were tested in total. The reference set was stored in the water until the time of testing. Another two sets of specimens were subjected to 50 and 100 freeze-thaw tests, respectively. One F-T cycle consisted of 4 hours freezing in the air at temperature -18 °C and 2 hours thawing in the water at temperature +20 °C. Based on the results, it can be stated that the values of fracture energy are proportional to the area of the ligament. This finding was observed for all tested sets – non-frost and frost attacked. The values of modulus of elasticity and fracture toughness are influenced more by the geometry and also by the changes of the specimens’ stiffness due to the exposition to the F-T cycles.

Diamidoamine Salt as the Admixture for Concrete Increasing the Resistance to the Freeze-Thaw Cycle

Concrete freeze-thaw resistance, along with compressive strength, is one of its basic features, which have a significant impact on the durability of structures of buildings and engineering structures. Numerous studies presented in domestic and foreign literature showed that there is a relationship between the concrete mix’s composition and the extent of frost damage. The frost durability of concrete depends on many factors. Therefore, cyclic changes of air temperature in winter conditions (over 100 freeze-thaw event cycles per year are estimated in Poland) must be taken into consideration as soon as in the phase of designing a concrete mix and structural elements. Proper designing of the concrete mix, optimal selecting of proportions and kinds of components, applying of appropriate kinds of additives and admixtures as well as proper maintenance of concrete can protect the investor against serious financial consequences. The paper discussed the influence of sub-zero temperatures effect on cement concretes properties. The requirements that are imposed on designers in terms of concretes resistance to frosts cyclic effect by the currently applicable standards were presented. The paper also presents the results of an original research programme showing the effectiveness of diamidoamine salt as an admixture for concretes that increases their resistance to the freeze-thaw cycle. Within the preliminary tests, the influence of the diamidoamine salt on early and 28-day compressive strength was marked. The air content in fresh concrete, absorbability and water permeability were also specified. The freeze-thaw resistance of concretes with the addition of the diamidoamine salt after 50 freeze-thaw cycles was determined. The conducted preliminary laboratory tests showed that applying the diamidoamine salt causes the decrease in compressive strength. This decrease is proportional to the admixture content. The applied admixture significantly decreases the absorbability, improves waterproofness and freeze-thaw resistance of the concrete.

Effect of cement type and limestone particle size on the durability of steam cured self-consolidating concrete

This paper describes a laboratory program to investigate the influence of cement and limestone filler (LF) particle size on the hardened properties and durability performance of steam cured self-consolidating concrete. In addition, the interplay between cement type and LF particle size was investigated. CSA (Canadian Standards Association) Type GU (General Use) and HE (High Early-strength) cements were used with 5% silica fume (SF) [1]. The water-to-cement ratio was 0.34. LF with two nominal particle sizes of 17 μm and 3 μm, which correspond to Blaine fineness of 475 and 1125 m2/kg, respectively, were used. In addition to fresh concrete properties, hardened properties including compressive strength, elastic modulus, ultrasonic pulse velocity and density were measured at 12 h and 16 h, and at 3, 7 and 28 days. Indicators of durability performance including rapid chloride permeability testing (RCPT), sulfate resistance, linear shrinkage, salt scaling resistance and freeze-thaw resistance were evaluated. The results showed that LF improved the 12 and 16-h strength with no influence on later age strength (i.e., 3–28 days). The linear shrinkage and RCPT decreased with the addition of LF. This reduction was linked to the production of calcium mono-carboaluminate. LF did not impact the sulfate resistance, salt scaling resistance or freeze-thaw resistance of concrete.

Analysis of durability testing of concrete landscaping units

In recent years the problem of the durability of vibrocompacted concrete products (landscaping elements, paving blocks in particular) has received great attention in Europe. In Easter Europe there are rather aggressive climate conditions (temperature fluctuations, humidity, precipitation, etc.). Besides, in winter concrete paving is treated with sodium, calcium, magnesium chloride salts that accelerate the deterioration of concrete paving block structure. European standard EN 1338:2003+AC:2006 that sets forth the basic requirements and test methods for concrete paving blocks does not take into account the performance of concrete products under specific climatic conditions. Therefore, it is important to determine the basic technological factors that influence the quality of vibrocompacted concrete, in particular freeze-thaw resistance, and to optimize the composition and other technological properties of vibrocompacted concrete. The freeze-thaw resistance of concrete has to be measured by different methods. The present paper describes the testing of concrete paving blocks, the top layer of which contained different amounts of cement ranging from 527 to 385kg/m3. The cement content in the bottom (support) layer compositions of all specimens remained the same – 371kg/m3. Density, freeze-thaw resistance according to two different methods, splitting tensile strength and abrasion resistance were measured in the tests.

Substantiation of Reference Method For Determining Concrete's Freeze-Thaw Resistance

It has been analytically proved that using concrete's rate of set e as a measure of damage, instead of decreasing of tensile strength R, increases freeze-thaw resistance's accuracy of estimation a lot under otherwise equal conditions by the time of freeze-thaw cycling. Also it has been experimentally shown that ratio of relative decreasing R to ε in direction, perpendicular to compression, is assumed to be independent on values R and ε for a given concrete and on the ways of achieving them during mechanical or freeze-thaw cycling. Taking this into account patented methods for estimation of concrete's freeze-thaw resistance as per values R and e received after freezing and thawing cycles of some specimens and their postliminary failure by linear compression was substantiated.

ITZ properties of concrete with carbonated steel slag aggregate in salty freeze-thaw environment

The concrete samples with carbonated steel slag aggregate (CSA), normal aggregate (NA) and crushed steel slag aggregate (SSA) with W/C of 0.42 were prepared. The properties of the resistance on freezing and thawing were investigated and compared by freeze-thaw test with the condition of fresh-water and salt-water. The rapid chloride migration test (RCM) and coulomb electric flux test (CEF) were made in order to test the resistance of the concrete to chloride ion penetration. The ITZ properties and freeze thaw resistance of concrete were investigated by micro hardness tests, SEM, Ca/Si ratios, weight loss and relative dynamic elastic modulus test. The results show that using CSA instead of NA increased the freeze-thaw cycles from about 30 cycles to 175 cycles in salt-water condition and from about 150 cycles to 300 cycles in fresh-water condition. The average value of the hardness of ITZ around CSA is more than 43, which may due to the low W/C ratio caused by high water absorption of the CSA. The range of interfacial transition zone (ITZ) of CSA from SEM and EDS is larger but denser than NA and SSA, and fewer cracks are observed. The resistance to freeze and thaw will be improved by the hydration of steel slag to bond cement matrix. The cambered surfaces of CSA are less likely to occur stress concentration.

Effect of Binder Composition on the Structure of Cement Paste and on Physical Properties and Freeze-Thaw Resistance of Concrete

The primary objective of this study was to determine how differences in the composition of the binder made with Portland cement, slag and/or fly ash affect the modification of the cement paste structure and the properties of concrete with respect to its freeze/thaw resistance. The test results show that the use of mineral additions (fly ash or a mixture of fly ash and slag) does not guarantee the impermeability and the frost resistant structure of concrete. The concrete behaves as expected up to the slag level of 20% by mass of the cement. The results from the tests conducted on non-air entrained concretes with W/B ratio of 0.45 (limiting value for concrete exposure class XF4) show that the concrete mix in any case should be air entrained when mineral additions are to be used.

Realization of Optional Method of Determining the Concrete's Freeze-Thaw Resistance with Help of Dilatometer

It’s really necessary to determine freeze-thaw resistance of concrete faster and correctly.The offered method is based on measurement of long strength by nondestructive method, based onacoustic issue. Also dilatometer is used. During this research, the theoretical analysis of concrete'sspecimen dependence on freeze-thaw resistance and energy, which is emitted by a specimen duringdestruction, has been carried out. Freeze-thaw resistance of a specimen is calculated as themathematical relation of these energies. Correctness of the offered method is proved byexperiments. The offered method is characterized by small labor input, high efficiency and a wideapplication scope, but special laboratory equipment is needed.

Freeze-thaw resistance of concrete using acid-leached rice husk ash

The main purpose of this research is to investigate the freeze-thaw resistance of concrete incorporating acid-leached rice husk ash. The research has been initiated because of its unique microstructural characteristic: rice husk ash maintains the original cellular structure of rice husk that has large amount of empty space, so it has a potential possibility of reducing the air void spacing factor. The freeze-thaw resistance of concrete using rice husk ash is compared to that using silica fume. The result shows that the freeze-thaw resistance of concrete using acid-leached rice husk ash is slightly less than that of silica fume concrete during 300 freeze-thaw cycles. When freeze-thaw cycles are extended to 600 cycles, freeze-thaw resistance of concrete using acid-leached rice husk ash is equivalent to the concrete using silica fume.

The Freeze-Thaw Resistance of Concrete Control Structure for Debris Flow on Tianshan Highway

The extreme climate in Tianshan area has a significant impact on the freeze-thaw resistance of concrete control structure for debris flow. This paper describes a fiber reinforced concrete designed for Tianshan area. The impact factors on the freeze-thaw resistance of concrete are analyzed. The optimal composition for concrete control structure is discussed. And the engineering economic of such material is compared with that of Portland cement concrete. Research results shows fiber reinforced concrete can greatly improve the freeze-thaw resistance of concrete, and significantly extend its life with a great of practical value.

NONDESTRUCTIVE TESTING OF ULTRA-HIGH PERFORMANCE CONCRETE TO EVALUATE FREEZE-THAW RESISTANCE

Recently increased attention has been given to materials, which could meet certain strength and durability requirements. Ultra high performance concrete (UHPC) is one of the materials which possess such properties. UHPC has excellent durability and mechanical properties and could be suitable for various construction applications, however all construction over time in aggressive environment loses its original designed properties. In this article researched one of the most important durability parameter – freeze-thaw resistance of concrete. This durability parameter is significant for constructions and materials used in Lithuania. Nondestructive test methods are one of the ways, which are suitable to investigate durability properties of UHPC. Each of the methods has its advantages or disadvantages and depending on environment will presents different reliability results. Durability properties of UHPC were investigated by ultrasonic and dynamic modulus of elasticity methods. The reliability of these test methods was verified by determining the compressive strength, and surface defects were visually inspected by fluorescence method. There are a few publications about freeze-thaw resistance of UHPC and fewer articles about concretes prediction to severe frost damage, however such research in Lithuania is not done at all.DOI: http://dx.doi.org/10.5755/j01.mech.18.2.1565

Experimental Study on Freeze-Thaw Resistance of Concrete with Proto-Machine-Made Sand

Experiments were conducted to study the effects of source rock state and stone powder on freeze-thaw resistance of concrete with proto-machine-made sand, the strength grade of concrete was C50, the source rock states were gravel and crushed stone, the contents of stone powder in sand were 5%, 9% and 13% respectively. The values of relative dynamic elastic modulus and mass of concrete at different freeze-thaw cycle times were measured, the reduction of relative dynamic elastic modulus and mass loss were calculated to evaluate the freeze-thaw resistance of concrete. The results show that freeze-thaw resistances are controlled by the reduction of relative dynamic elastic modulus of concrete, which are good of concrete with proto-machine-made sand of gravel and crushed stone, and increases with the increasing content of stone powder in sand made of gravel. The reasons leading to difference of freeze-thaw resistance of concrete with sand made of gravel and crushed stone are discussed.