Effect of Temperature-Match-Curing on Freeze-Thaw and Scaling Resistance of High-Strength Concrete

2004 ◽  
Vol 26 (1) ◽  
pp. 1-5 ◽  
Author(s):  
JonA. Jonsson ◽  
Jan Olek
Keyword(s):  
High Strength Concrete ◽  
High Strength ◽  
Effect Of Temperature ◽  
Freeze Thaw ◽  
Strength Concrete ◽  
Scaling Resistance

Performance Deterioration of High Strength Concrete under Mixed Erosion and Freeze-Thaw Cycling

2010 ◽  
Vol 163-167 ◽  
pp. 1655-1660
Author(s):  
Jian Zhang ◽  
Bo Diao ◽  
Xiao Ning Zheng ◽  
Yan Dong Li
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Mass Loss ◽  
Modulus Of Elasticity ◽  
Dynamic Modulus ◽  
High Strength Concrete ◽  
High Strength ◽  
Freeze Thaw ◽  
Strength Concrete ◽  
Dynamic Modulus Of Elasticity

The mechanical properties of high strength concrete(HSC) were experimentally investigated under mixed erosion and freeze-thaw cycling according to ASTM C666(Procedure B), the erosion solution was mixed by weight of 3% sodium chloride and 5% sodium sulfate. The mass loss, relative dynamic modulus of elasticity, compressive strength, elastic modulus and other relative data were measured. The results showed that with the increasing number of freeze-thaw cycles, the surface scaled more seriously; the mass loss, compressive strength and elastic modulus continued to decrease; the relative dynamic modulus of elasticity increased slightly in the first 225 freeze-thaw cycles, then decreased in the following 75 cycles; the corresponding strain to peak stress decreased with the increase of freeze-thaw cycles. After 200 cycles, the rate of deterioration of concrete accelerated obviously.

scholarly journals Thermal Properties of Conventional and High-strength Concrete

2018 ◽  
Vol 245 ◽  
pp. 06005 ◽  
Author(s):  
Tatiana Musorina ◽  
Alexsander Katcay ◽  
Mikhail Petrichenko ◽  
Anna Selezneva
Keyword(s):  
Thermal Properties ◽  
Thermophysical Properties ◽  
High Strength Concrete ◽  
High Strength ◽  
Temperature Fluctuations ◽  
Conventional Concrete ◽  
Freeze Thaw ◽  
Strength Concrete ◽  
Concrete Properties ◽  
Cold Chamber

Important characteristics for the Nordic countries: a freeze-thaw resistance and an ability of a material to keep heat inside the building. This paper aims to define the thermophysical properties of a high-strength concrete, compare the discovered performance with the conventional concrete properties. With this object in mind two experiments in cold chamber “CHALLENGE 250” have been conducted and followed by analysis. In these experiments, the insulation of facades is beyond the framework of the investigation. Only the thermophysical properties of concrete are taken into account. The samples were affected by temperature fluctuations. Results from the experiments show that strength characteristics of a material are in indirect ratio to accumulation properties of a structure. This conclusion is directly related to porosity of material and additives. During 70 minutes, with outside temperature being below zero, the temperature inside the concrete dropped to an average. As the outside temperature increases significantly to more than zero, the temperature inside the concrete has become below average (continued to decline) in 70 minutes. The more strength of material, the better thermophysical properties. High-strength concrete is less susceptible to temperature fluctuations, therefore more heat-resistant. As mentioned in the paper below, the material has one disadvantage: this is a large cost per cubic meter.

Performance Comparison between High Strength Concrete and Ordinary Concrete under Mixed Erosion and Freeze-Thaw Cycling

2010 ◽  
Vol 163-167 ◽  
pp. 1667-1672
Author(s):  
Jian Zhang ◽  
Bo Diao ◽  
Yan Dong Li ◽  
Xiao Ning Zheng
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
High Strength Concrete ◽  
Mass Loss Rate ◽  
Peak Stress ◽  
High Strength ◽  
Performance Comparison ◽  
Freeze Thaw ◽  
Strength Concrete ◽  
Ordinary Concrete

: Performance of high strength concrete and ordinary concrete under alternating action of mixed erosion and freeze-thaw cycling were compared. The erosion solution was mixed by weight of 3% sodium chloride and 5% sodium sulfate. Results showed that, after 200 freeze-thaw cycles, the effect of surface scaling of ordinary concrete was more significant than that of high strength concrete, and the mass loss rate of ordinary concrete was much higher; The relative dynamic modulus of elasticity of high strength concrete slightly increased by 2.99%, while that of ordinary concrete decreased more than 13%. Compressive strength and elastic modulus of high strength and ordinary concrete behaved almost in the same way in the first 50 freeze-thaw cycles, with the increase of freeze-thaw cycles in the following test, the compressive strength and elastic modulus of ordinary concrete showed larger reductions than these of high strength concrete. As the freeze-thaw cycles increased, the corresponding strain to the peak stress of high strength concrete decreased, but it increased for ordinary concrete.

scholarly journals Chloride Ion Corrosion Pattern and Mathematical Model for C60 High-Strength Concrete after Freeze-Thawing Cycles

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Yan Li ◽  
Bing Li ◽  
Lian-ying Zhang ◽  
Chao Ma ◽  
Jiong Zhu ◽  
...  
Keyword(s):  
Mathematical Model ◽  
High Strength Concrete ◽  
Chloride Ion ◽  
High Strength ◽  
Chloride Ions ◽  
Diffusion Method ◽  
Freeze Thaw ◽  
Strength Concrete ◽  
Artificial Environment ◽  
Transport Control

In this study, the porosities of C60 high-strength concrete after 0, 30, 60, and 90 freeze-thaw cycles determined via the water retention method are 1.30%, 3.65%, 5.14%, and 7.34%, respectively. Furthermore, a mathematical model of porosity varying with the number of freeze-thaw cycles is established. Using an artificial environment simulation experimental system and the natural diffusion method, the chloride diffusion law of C60 high-strength concrete after 0, 30, 60, and 90 freeze-thaw cycles is obtained. The corresponding diffusion coefficients are calculated based on the experimental results and Fick’s law, where 0.3431 × 10−12, 0.5288 × 10−12, and 0.6712 × 10−12, and 0.8930 × 10−12 m2/s are obtained, respectively, and a mathematical model of diffusion coefficient with freeze-thawing is established. Transport control equations comprising solution flow and solute migration control equations are established for chloride ions in concrete after freeze-thawing cycles. The equations consider the effects of freeze-thawing, solution pressure, solution concentration, solution density, convection, mechanical dispersion, and chemisorption on chloride ion transport in concrete. Using COMSOL numerical software, the transport control equations for chloride ions are solved using a real concrete numerical model, and the chloride ion corrosion process in concrete after freeze-thaw cycles is simulated. The simulation results are consistent with the experimental values.

scholarly journals STRESS-STRAIN BEHAVIOR OF HIGH-STRENGTH CONCRETE REINFORCED WITH POLYPROPYLENE FIBERS

2020 ◽  
Author(s):  
Г.Д. Ляхевич ◽  
В.А. Гречухин ◽  
С. Мотамеди
Keyword(s):  
Compressive Strength ◽  
High Strength Concrete ◽  
Polypropylene Fiber ◽  
Three Dimensional ◽  
High Strength ◽  
Strength Characteristics ◽  
Effect Of Temperature ◽  
Polypropylene Fibers ◽  
Strength Concrete ◽  
Concrete Mix

Целью настоящего исследования является исследование влияния полипропиленовых волокон, вводимых в бетонную смесь, на прочностные характеристики и снижение эффекта взрывного откалывания в бетоне, при повышении температуры. Полипропиленовая фибраобразует в бетоне трехмерный армирующий каркас, который воспринимает растягивающие усилия. Ее применение повышает долговечность, снижает истираемость поверхности, повышает ударную вязкость, устраняет усадку, предупреждает образование трещин, повышает морозостойкость. Для приготовления бетонной смеси использовали следующие компоненты: цемент марки М-500, песок кварцевый, щебень, микрокремнезем, суперпластификатор, вода, полипропиленовая фибра. Водоцементное отношение в испытании составило от 0,23 до 0,32. С целью изучения влияния температуры на прочностные характеристики высокопрочного бетона приготовили 16 составов бетонной смеси. Образцы нагревали до температуры 800 °С при скорости нагрева около 20 °С в минуту. После достижения данной температуры образцы в течение 24 часов медленно остывали до комнатной температуры, после чего измерялось снижение их массы и остаточное сопротивление на сжатие. При нагревании образцов в интервале температур от 160 °С до 180 °С в бетоне с ППВ происходит образование каналов, по которым при дальнейшем нагревании выходит пар. Испытания показали, что в образцах с полипропиленовым волокном (ППВ) не наблюдается эффекта взрывного откалывания. Полипропиленовые волокна уменьшают потерю сопротивления, и устраняют хрупкое разрушение. В исследовании изучено влияние длины и количества ППВ на прочность бетона на сжатие. Использование полипропиленовых волокон повышает огнестойкость и хрупкость высокопрочного бетона, способствует его вязкому разрушению. Образцы бетона без ППВ после нагружения полностью разрушились, тогда, как образцы бетона с ППВ при аналогичной нагрузке сохранили свою геометрию. Введение волокна в высокопрочный бетон способствует повышению прочности на сжатие и термостойкости образцов. После расплавления волокон, образовались капилляры, через которые пар может выйти из массива бетона, предотвращая, таким образом, взрывное откалывание бетона. The purpose of this study is to study the effect of poly-propylene fibers introduced into the concrete mix on the strength characteristics and reduction of the effect of explosive chipping in concrete when the temperature increases. Polypropylene fiber forms a three-dimensional reinforcing frame in concrete that accepts tensile forces. Its use increases durability, reduces surface abrasion, increases impact strength, eliminates shrinkage, prevents the formation of cracks, and increases frost resistance. The following components were used to prepare the concrete mix: M-500 cement, quartz sand, crushed stone, microsilicon, superplasticizer, water, polypropylene fiber. The water-cement ratio in the test was from 0.23 to 0.32. In order to study the effect of temperature on the strength characteristics of high-strength concrete, 16 concrete mix compositions were prepared. The samples were heated to a temperature of 800 °C at a heating rate of about 20 °C per minute. After reaching this temperature, the samples were slowly cooled to room temperature for 24 hours, after which the decrease in their mass and residual compressive resistance were measured. When samples are heated in the temperature range from 160 °C to 180 °C in concrete with PPV, channels are formed through which steam escapes during further heating. Tests have shown that there is no explosive chipping effect in samples with polypropylene fiber (PPV). Polypropylene fibers reduce the loss of resistance, and eliminate brittle fracture. The study examined the effect of the length and amount of PPV on the compressive strength of concrete. The use of polypropylene fibers increases the fire resistance and brittleness of high-strength concrete, contributes to its viscous destruction. Samples of concrete without PPV after loading completely collapsed, while samples of concrete with PPV under a similar load retained their geometry. The introduction of fiber into high-strength concrete increases the compressive strength and heat resistance of samples. After melting the concrete, capillaries were formed through which steam can escape from the concrete mass, thus preventing explosive chipping of the concrete.

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