Experimental Study of Compression and Carbonation in Concrete Subjected to Freeze-Thaw Environment

2014 ◽  
Vol 887-888 ◽  
pp. 814-818
Author(s):  
Li Xue Wang ◽  
Xiao Ting Shan ◽  
Yu Qing Zhang ◽  
Chun Sheng Li ◽  
Zai Xing Wang ◽  
...  

In order to research the changes of concrete properties in freeze-thaw environment, five concrete samples with water-cement ratio respectively equal to 0.60, 0.65, 0.70, 0.75 and 0.80 were tested in freeze-thaw environment according to GB/T50082-2009 concrete rapid freeze-thaw cycles test method. Five samples were carried out 0, 25, 50, 75, 100 times faster freeze-thaw cycles test. With the increasing number of freeze-thaw cycles, the concrete relative dynamic modulus of elasticity loss rises, the compressive strength drops, and the carbonation depth increases. The greater the water-cement ratio of concrete specimens with freeze-thaw cycles, the greater the degree of damage increases.

2014 ◽  
Vol 1065-1069 ◽  
pp. 1899-1902
Author(s):  
Yan Kun Zhang ◽  
Yu Cheng Wang ◽  
Xiao Long Wu

In this article, the flexural strength of combined aggregate concrete with four kinds of water-cement ratio (0.3,0.35.0.4, 0.45), and six ceramsite replace rate (0%, 20%, 40%, 60%, 80%, 60%) are studied with comprehensive test method. Experiment shows that the ceramsite replace rate of combined aggregate has greater influence on the flexural strength than the water-cement ratio. The flexural strength increases with the increasing of compressive strength, and the formula of the flexural strength and compressive strength of combined aggregate concrete is given.


2014 ◽  
Vol 912-914 ◽  
pp. 131-135
Author(s):  
Xiang Ping Fu ◽  
Xiao Xue Liu ◽  
Yi Ze Sun ◽  
Pei Huang ◽  
Yu Chen Li ◽  
...  

The experiment studies how the freeze-thaw cycles influence concrete compressive strength and elasticity modulus with different water-cement ratio under the air-entraining agent and zero of that value respectively. It can be found that modulus of elasticity and compressive strength of the concrete specimen reduced significantly when there is air-entraining agent; the durability of freeze-thaw resistance, however, makes great improvement; as the cement increases, both of them improves effectively. Through the comparison of concrete compressive strength and elastic modulus with different water-cement ratio and air-entraining agent, the optimal water-cement ratio and air-entraining agent were determined. The results of experiment can be used in concrete engineering design in severe cold area.


2017 ◽  
Vol 904 ◽  
pp. 179-184
Author(s):  
Seung Jo Lee

The purpose of this study is to investigate the freeze-thaw resistance, one of the most important durability indicators, of high-performance concrete made of fibers (nylon and polypropylene), AE agent, viscosity agent, and fly ash, an industrial by-product. While FN-1 showed the best freeze-thaw resistance with an about 2.8% relative dynamic modulus of elasticity, PV-2 showed the worst results, with an about 7.4% modulus, in comparison tests with GC. Most of the test samples showed better compressive strength than GC. Especially, N-1 showed the greatest compressive strength increase of 8%. Also, the test samples mixed with FA and PP showed a 2-4% compressive strength increase effect.


2019 ◽  
Vol 2 (2) ◽  
pp. 126-136
Author(s):  
M.I Retno Susilorini ◽  
Budi Eko Afrianto ◽  
Ary Suryo Wibowo

Concrete building safety of fire is better than other building materials such as wood, plastic, and steel,because it is incombustible and emitting no toxic fumes during high temperature exposure. However,the deterioration of concrete because of high temperature exposure will reduce the concrete strength.Mechanical properties such as compressive strength and modulus of elasticity are absolutely corruptedduring and after the heating process. This paper aims to investigate mechanical properties of concrete(especially compressive strength and modulus of elasticity) with various water-cement ratio afterconcrete suffered by high temperature exposure of 500oC.This research conducted experimental method and analytical method. The experimental methodproduced concrete specimens with specifications: (1) specimen’s dimension is 150 mm x 300 mmconcrete cylinder; (2) compressive strength design, f’c = 22.5 MPa; (3) water-cement ratio variation =0.4, 0.5, and 0.6. All specimens are cured in water for 28 days. Some specimens were heated for 1hour with high temperature of 500oC in huge furnace, and the others that become specimen-controlwere unheated. All specimens, heated and unheated, were evaluated by compressive test.Experimental data was analyzed to get compressive strength and modulus of elasticity values. Theanalytical method aims to calculate modulus of elasticity of concrete from some codes and to verifythe experimental results. The modulus elasticity of concrete is calculated by 3 expressions: (1) SNI03-2847-1992 (which is the same as ACI 318-99 section 8.5.1), (2) ACI 318-95 section 8.5.1, and (3)CEB-FIP Model Code 1990 Section 2.1.4.2.The experimental and analytical results found that: (1) The unheated specimens with water-cementratio of 0.4 have the greatest value of compressive strength, while the unheated specimens with watercementratio of 0.5 gets the greatest value of modulus of elasticity. The greatest value of compressivestrength of heated specimens provided by specimens with water-cement ratio of 0.5, while the heatedspecimens with water-cement ratio of 0.4 gets the greatest value of modulus of elasticity, (2) Allheated specimens lose their strength at high temperature of 500oC, (3) The analytical result shows thatmodulus of elasticity calculated by expression III has greater values compares to expression I and II,but there is only little difference value among those expressions, and (4)The variation of water-cementratio of 0.5 becomes the optimum value.


2010 ◽  
Vol 163-167 ◽  
pp. 1655-1660
Author(s):  
Jian Zhang ◽  
Bo Diao ◽  
Xiao Ning Zheng ◽  
Yan Dong Li

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.


1990 ◽  
Vol 17 (1) ◽  
pp. 102-112
Author(s):  
T. Rezansoff ◽  
D. Stott

The influence of CaCl2 or a chloride-based accelerating admixture on the freeze–thaw resistance of concrete was evaluated. Three air entrained mix designs were investigated using ASTM C666-84, Standard Test Method for Resistance of Concrete to Rapid Freezing and Thawing. All mix designs were similar, using cement contents of 340–357 kg/m3 of concrete, except for the addition of either 2% calcium chloride or 2% High Early Pozzolith, while no accelerating admixture was added to the control mix. The entire test program was repeated four times with water-to-cement ratio of 0.46 and three times with the ratio of 0.43. For the Pozzolith-accelerated concrete, half the samples were coated with boiled linseed oil in all seven series. For the control (unaccelerated) concrete, half the samples were coated with boiled linseed oil in one series for each water-to-cement ratio. Performance was monitored using the dynamic modulus of elasticity as obtained from transverse resonant frequency measurements. Weight loss of the specimens was also measured. Only the control samples (no accelerators) showed sufficient durability to satisfy the standard of maintaining at least 60% of the original dynamic modulus after 300 cycles of alternate freezing and thawing. Sealing with linseed oil showed inconsistent improvement in the durability in the various test series when defined in terms of the dynamic modulus; however, weight losses were the lowest of all categories and surface scaling was minimal. Key words: concrete, durability, freeze–thaw testing, calcium chloride, admixtures, sealants, air void system.


2014 ◽  
Vol 1054 ◽  
pp. 128-131
Author(s):  
Klára Křížová ◽  
Petr Novosad ◽  
Denisa Orsáková

The paper presents obtained results of self-compacting concretes with various compositions with focus on basic characteristics development. Firstly the fresh concrete properties are summed and self-compactness classes are categorised and subsequently the values of compressive strength, static and dynamic modulus of elasticity of hardened concretes are compared. All the stated parameters were monitored during different ages of the concrete and therefore they provide a view of its development in time. With still enlarging scale of concrete types and development of their application it is necessary to monitor common parameters which due to the application of new concepts in raw material compositions and use of higher amounts of additives may notably differ compared to applied orthodox concrete parameters.


2013 ◽  
Vol 405-408 ◽  
pp. 2801-2805
Author(s):  
Ji Feng Liang ◽  
Lei Lv ◽  
Feng Wang

The use of orthogonal test method, the concrete mixed with limestone power and fly ash was carried out static compressive experiment, and contrast with the experiment of single doped with limestone powder and fly ash concrete. The experimental result demonstrated that the compressive strength enhancement effect of the concrete mixed with limestone power and fly ash was obvious. The importance of each factor affecting static compressive strength as follows: water-cement ratio, the amount of fly ash, the amount of limestone powder, sand ratio. The concrete compressive strength reached the maximum when the water-cement ratio reached 0.3, the limestone powder content reached 15%, the fly ash content reached 10%, and sand ratio reached 34%.


2019 ◽  
Vol 9 (2) ◽  
pp. 152-166 ◽  
Author(s):  
Ronaldo Alves de Medeiros-Junior ◽  
Guilherme da Silva Munhoz ◽  
Marcelo Henrique Farias de Medeiros

This research confronts the following concrete properties: water absorptions (by immersion and capillarity), electrical resistivity and compressive strength. Concrete mixtures with two types of cement were tested. Results showed that concretes with higher content of pozzolan had higher resistivity and greater absorption by capillarity, for water/cement ratios lower than 0,60. This behavior is attributed to reduced pore diameters and microstructure densification. However, for water/cement ratio of 0,60, concrete with lower content of pozzolan presented higher absorption by capillarity. It was observed that the compressive strength and the electrical resistivity behaved inversely proportional to the water/cement ratio, and the absorption by immersion and capillarity are directly proportional to the water/cement ratio. Correlations with high determination coefficients were found between tests.


Sign in / Sign up

Export Citation Format

Share Document