Freeze-thaw Durability Of Concrete Research Articles

Prediction of Progressive Frost Damage Development of Concrete Using Machine-Learning Algorithms

Understanding the deterioration mechanism of concrete structures in cold climates that are susceptible to frost damage from repeated freezing and thawing cycles is imperative for ensuring their durability and serviceability. This study analyzed the impact of freeze–thaw (FT) exposure on concrete structural behavior by developing three machine-learning approaches—artificial neural networks (ANN), random forests (RF), and support vector machines (SVM)—to quantify the progressive loss in compressive strength after repeated FT cycles. The results demonstrate that all of the proposed models can predict the deteriorated compressive strength of concrete and align closely with the experimental results. The ANN model demonstrated the highest prediction accuracy with an R2 of 0.924, exhibiting a higher prediction accuracy than RF and SVM models. Sensitivity analysis using Shapley additive explanations (SHAP) revealed that concrete with an initially high strength, along with a lower water–cement ratio and air entrainment, exhibited the least reduction in compressive strength after freezing–thawing cycles, underlining the positive impact of these factors on the FT durability of concrete. The proposed modeling approach accurately predicts the residual compressive strength after FT exposure, enabling the selection of optimal concrete materials and structural designs for cold climates.

The freeze-thaw durability of concrete containing the rubber aggregate of tire waste

The freeze-thaw durability of concrete containing the rubber aggregate of tire waste

Evaluation of the freeze-thaw durability of surface-treated airport pavement concrete under adverse conditions

In this experimental study, four kinds of conventional concrete surface treatments were selected for evaluation of surface treatment on the freeze-thaw durability of airport pavement concrete under the coupled effect of freeze-thaw cycles, ultraviolet radiation, abrasion, and flame erosion. Relative dynamic elastic modulus and freeze-thaw mass loss ratio were used to characterize the performance of the surface treatments. Experimental results indicated that the freeze-thaw durability of concrete coated with surface treatments improved in comparison with non-coated concrete. The performance difference of the four surface treatments can be expressed in the following order: silane > modified polyurea > AH material > epoxy resin. In order to investigate the influence of surface treatment durability on concrete freeze-thaw durability, scanning electron microscopy (SEM) images were collected. SEM images indicate that: (1) silane has good environment applicability; (2) modified polyurea has good freeze-thaw resistance and is susceptible to high temperature; (3) AH material has excellent high temperature performance and poor freeze-thaw resistance; (4) epoxy resin has poor weathering resistance. Having a better understanding of the properties of each surface treatment increases the successful application of surface treatments in accordance with the demand of airports.

Freeze-Thaw Durability of Concrete with Natural and Recycled Concrete Aggregates Using Air-Entraining Admixture

Abstract Freezing and thawing cycles are one of the most damaging factors that affect the durability of concrete. The damages caused by cyclic freeze-thaw (F-T) action can be divided into two factors. The first factor is an increase in internal cracking, which causes the loss in relative dynamic modulus (RDM) of the concrete, and the second factor is surface scaling, which leads to weight loss of the concrete. In this study, the durability of concrete made by replacing natural coarse aggregates (NCA) with various percentages of recycled concrete aggregates (RCA) is measured for an F-T test. Also, some tests have been conducted with the addition of air-entraining admixture (AEA). Prior to mixing the concrete, both NCA and RCA were characterized to determine their suitability as a construction material. Concrete mixes consisting of 0, 20, 40, 60, 80, and 100 % replacement (by weight) of NCA with RCA were prepared. The same concrete mixes were prepared again with the addition of AEA. All specimens were tested for compressive strength after a curing period of 7, 14, and 28 days. The compressive strength of the concrete made with different percentages of RCA decreases as the percentage of RCA increases. After 28 days of curing, sample with 0, 40, and 100 % replacement of NCA with RCA were placed without AEA in the F-T chamber, along with 0, 20, 40, 60, 80, and 100 % NCA replacements containing AEA. After several cycles of freezing and thawing, the RDM, change in weight, and change in length were measured. The RDM loss and weight loss were noticed, as the cyclic F-T durability increased. It has also been observed that concrete mixes containing AEA were still durable after 300 cycles of freezing and thawing; however, the specimens without AEA failed before 150 cycles.

The effect of synthetic zeolite on hardened cement paste microstructure and freeze-thaw durability of concrete

Tests were done with synthetic zeolite obtained by synthesizing alumina fluoride production residue, sodium hydroxide and alumina hydroxide. The synthesis lasted for two hours at 95°C temperature. The obtained product was a mix of synthetic zeolite of modifications A and X. The binding material was cement CEM I 42.5R. The test results revealed that substitution of cement with 10% of synthetic zeolite reduces water absorption of hardened cement paste ∼23.8%; the addition of air entraining admixture does not change the rate of water absorption. With the increase of zeolite content in concrete with and without air entraining admixture increases the volume of closed pores from 1.6% to 2.1% and from 4.1% to 7.6% respectively. The open porosity determined by water absorption of concrete with and without air entraining admixture changes insignificantly. The average distance between pores reduces from 360μm to 190μm when part of concrete is replaced by zeolite addition without air entraining admixture and from 190μm to 130μm in the case of using air entraining admixture. The addition of 10% of synthetic zeolite results in reduced content of portlandite and development of hydro aluminate compounds C3AH6 (cubic crystals) in hardened cement paste. Rose-shaped plates of calcium hydrosulphoaluminates (mono sulphate form) were also detected. These crystals together with hydroaluminates fill in the pores of hardened cement paste and thus reduce the open porosity of concrete. Substitution of 10wt% of cement with synthetic zeolite addition increases the freeze-thaw resistance of concrete, i.e. reduces the loss of surface mass after 28 freeze-thaw cycles more than 1.6 times without the air entraining admixture and up to 3.5 times with air entraining admixture.

Effect of hydrophobic surface treatment on freeze-thaw durability of concrete

The effect of surface treatment using silanes on the frost durability is investigated on both laboratory and field specimens in an accelerated laboratory test. Measurements include moisture uptake during the pre-saturation and F-T stages, cumulative mass loss and internal bulk cracking under frost salt/water exposure. It is found silane treatment substantially reduces surface scaling, but cannot prevent bulk moisture uptake or the occurrence of the internal frost damage when concrete is insufficiently air entrained. Salt scaling is dominated by the capillary suction process in the thin surface region under freezing which can be curtailed by the pore lining effect from silanes creating a hydrophobic barrier to the ingress of external liquid. This in turn suppresses ice growth in the surface region, evidenced by the complete elimination of sub-freezing dilation in a length-change measurement of small-scale concrete specimens with surface treatment. However, internal frost damage is controlled by the universal degree of pore saturation which in turn is dependent on the bulk moisture uptake.

The Effect of Crumb Rubber on Freeze-Thaw Durability of Portland Cement Concrete

Scrap tires from automobiles create a significant waste stream all over the world, and their disposal needs a viable and environmentally friendly solution. Past research shows that the inclusion of rubber aggregates in concrete reduces its strength but may be useful for improving durability properties such as the freeze-thaw resistance of the concrete; however, comprehensive assessments of the size effects and ideal rubber type have not been fully undertaken. With an understanding of the factors that enable rubber particles to improve the freeze-thaw resistance of concrete, issues such as instability and loss of entrained air in conventionally air-entrained concretes may be addressed. In this study, we assessed the freeze-thaw durability of rubberized Portland cement concrete with the addition of two types of crumb rubber aggregates created via ambient and cryogenic processes. Also, three different sizes of crumb rubber aggregates at three different replacement levels, 8 %, 16 %, and 24 % by volume of fine aggregates, were used for concrete specimens. The results were compared with non-air-entrained concrete as well as air-entrained concrete without added rubber. Based on this investigation, it was concluded that the finer-sized particles of both types of crumb rubber at 16 % and 24 % replacement levels showed very good performance in improving the freeze-thaw durability of concrete without the need for conventional air entrainment.

Stochastic Damage Model of Concrete during Freeze-Thaw Process

Abstract. The anti-frost property of concrete is one of the major parts of study on the durability of concrete. By viewing all over the world, due to the alternation of external temperature upon and under zero centigrade, concrete structures located on the areas of high latitude are usually unavoidable to suffer the damage caused by freeze-thaw cycles. Due to the insufficiency of theoretical foundation and the complexity of freeze-thaw durability itself, the contemporary studies are far from integrity in respect to the theoretical consensus. What is more, the researching measures concentrate more on the experimental approach. Based on this, it would be necessary to carry out relevant theoretical study on the freeze-thaw durability of concrete. The freeze-thaw damage of concrete is equivalent to that when internally generated hydrostatic pressure during freezing thawing process is greater than the destruction produced by then tensile strength of concrete. Although hydrostatic pressure is uniform in all directions, concrete is a kind of uneven brittle material. When it's under the stress by three even directions, the final destruction always happens in the weakest section, which is very similar to tensile breakage. In this case, unilateral tensile can be used to simulate the internal hydrostatic pressure affection of concrete during freezing and thawing process. In this article, one-dimensional micromechanical model of random damage will be used to the research of freeze-thaw damage and try to quantify it.

Stochastic Damage Model of Concrete during Freeze-Thaw Process

Abstract. The anti-frost property of concrete is one of the major parts of study on the durability of concrete. By viewing all over the world, due to the alternation of external temperature upon and under zero centigrade, concrete structures located on the areas of high latitude are usually unavoidable to suffer the damage caused by freeze-thaw cycles. Due to the insufficiency of theoretical foundation and the complexity of freeze-thaw durability itself, the contemporary studies are far from integrity in respect to the theoretical consensus. What is more, the researching measures concentrate more on the experimental approach. Based on this, it would be necessary to carry out relevant theoretical study on the freeze-thaw durability of concrete. The freeze-thaw damage of concrete is equivalent to that when internally generated hydrostatic pressure during freezing thawing process is greater than the destruction produced by then tensile strength of concrete. Although hydrostatic pressure is uniform in all directions, concrete is a kind of uneven brittle material. When it's under the stress by three even directions, the final destruction always happens in the weakest section, which is very similar to tensile breakage. In this case, unilateral tensile can be used to simulate the internal hydrostatic pressure affection of concrete during freezing and thawing process. In this article, one-dimensional micromechanical model of random damage will be used to the research of freeze-thaw damage and try to quantify it.

Freeze-Thaw Durability of Portland Cement Concrete Subjected to Aircraft Deicer

Influence of glycol, which is the main composition of the most frequently used aircraft dicer, on the freeze-thaw durability of Portland cement concrete were investigated. Freeze-thaw durability of Portland cement concrete was tested by accelerated freeze-thaw test. Four kinds of solutions, namely tap water, 3.5% NaCl solution, glycol solutions and a LBR-A type commercial aircraft deicer were employed to be the freezing-thawing mediums. Results show that freeze-thaw durability of concrete exposed to glycol solutions is closely related to the solution concentrations. Failure of concretes exposed to 3.5% glycol solution is similar to that of those exposed 3.5% NaCl solution, which are attributed to serious surface scaling. While damage of concrete exposed to 12.5% and 25% glycol solutions are postponed, and the durability of concrete are increased. Compared with glycol solution, the commercial aircraft deicer demonstrated much more negative effect to concrete freeze-thaw durability, and the degree even exceeds 3.5% NaCl solution. Consequently, the commercial aircraft deicer is not a kind of environmental friendly deicer as usually considered.

Durability of concrete subjected to the combined actions of flexural stress, freeze-thaw cycles and bittern solutions

Freeze-thaw durabilities of three types of concretes-normal portland cement concrete (OPC), high strength concrete (HSC) and steel fiber reinforced high strength concrete (SFRHSC) were systemically investigated under the attacks of chemical solution, and combination of external flexural stress and chemical solution. Four kinds of bitterns from salt lakes in Sinkiang, Qinghai, Inner Mongolia and Tibet provinces of China were used as chemical attack solutions. The relative dynamic modulus (RDM) was used as an index for evaluating the damage degree during the course of chemical attack and stress corrosion. The experimental results show that the freeze-thaw durability of concrete is visibly reduced in the present of the flexural stress, i e, stress accelerates the damage process. In order to quantify the stress accelerated effect, a stress accelerating coefficient was proposed. The stress accelerating coefficient is closely related with the types of bitterns and the numbers of freeze-thaw cycles is. The more numbers of freeze-thaw cycles is, the greater the stress accelerating coefficient for various concretes will be. In addition, there also exists a critical ratio of external stress to the maximum flexural stress. If the stress ratio exceeds the critical one, the freeze-thaw durability of various concretes will be greatly decreased compared to the responding concretes without applied stress. The critical stress ratio of OPC, HSC and SFRHSC is 0.30, 0.40 and 0.40, respectively, indicating that HSC and SFRHSC have advantages over OPC and are suitable to use in the bittern erosion regions.

Preliminary Study for Strength and Freeze-Thaw Durability of Microwave- and Steam-Cured Concrete

This study investigates the effects of steam and microwave curing on the strength development and freeze-thaw durability of concrete. Two steam-curing treatments, four microwave curing times and four types of concrete mix, were used in this study. The test results indicated that microwave heating could further increase the early strength of concrete. Pozzolanic reaction of silica fume, fly ash, and blast-furnace slag was observed to be further promoted by steam-microwave curing. Concrete samples with 10% silica fume added responded well to microwave curing. The strength gain development of concrete appeared to level off after 40 min of microwave curing. Thus, a 40-min microwave heating time appeared to be the optimal curing time. The microwave-cured concrete did not show an increase in deterioration relative to the concrete that was steam cured, but showed an increase in strength. The strength of the top layer of the steam-cured concrete blocks is lower than the strength of the middle or bottom layer.

Freeze-thaw durability of concrete: ice formation process in pores

Freeze-thaw durability of concrete is of great importance to hydraulic structures in cold areas. Study of ice formation process in concrete pores is necessary to evaluate the damages in concrete caused by freezing. In this paper, freezing of pore solution in concrete exposed to a freeze-thaw cycle is studied by following the change of concrete electrical conductivity with freezing temperatures. Concretes were subjected to freeze-thaw cycles with temperature varying between −0°C and −20°C . In the freezing process, the changing rate of concrete electrical conductivity obviously decreases at about −10°C, indicating that more pore solution in concrete freezes above −10°C than below −10°C. According to Powers’ static hydraulic pressure hypothesis, it is thought that frost damage mainly occurs between 0°C and −100°C. To ordinary concrete, frost damages below −10°C are negligible.

Freeze-Thaw Durability of Concrete With and Without Silica Fume in ASTM C 666 (Procedure A) Test Method: Internal Cracking Versus Scaling

Abstract The freeze-thaw durability of concrete with and without silica fume was investigated in accordance with the requirements of ASTM Test Method for Resistance of Concrete to Rapid Freezing and Thawing (C 666 Procedure A). The water-cement ratio of all mixes was 0.5, and the silica-cement ratio of the silica fume mixes 0.1. The test results show that the critical value of the air-void spacing factor in these ASTM C 666 tests is significantly lower for the silica fume concretes. These concretes are therefore more susceptible to internal cracking caused by rapid freeze-thaw cycles in water, even though the use of silica fume decreased the surface scaling of the test specimens. This confirms that scaling and internal cracking are two different forms of frost damage caused by rapid freeze-thaw cycles in water. The use of silica fume also decreased the internal cracking of the nonair-entrained mixes damaged during the tests.