Experimental Study on Frost Resistance Durability and Service Life Prediction of Normal Cement Concrete

2011 ◽  
Vol 368-373 ◽  
pp. 2425-2429 ◽  
Author(s):  
Shi Zhu Lin ◽  
Hui Min Li ◽  
Hong Yan Zhang
Keyword(s):  
Elastic Modulus ◽  
Mass Loss ◽  
Loss Rate ◽  
Mass Loss Rate ◽  
Northern China ◽  
Standard Test ◽  
Dynamic Elastic Modulus ◽  
Operation Conditions ◽  
Thawing Process ◽  
Actual Operation

The existing concrete structures, especially hydraulic dams, in the cold areas of northern China have suffered from freeze-thaw damages to varying degrees in the small part or the vast areas of the projects. This paper will work out the performance deterioration index with the relative dynamic elastic modulus and the mass loss rate of the concrete. The test shows that there is a linear relationship between the concrete's relative dynamic elastic modulus and the increasing number of freezing-thawing cycles; the mass loss rate, however, varies with the water-cement ratio and displays different tendency of changes in the initial phase of the cycle, but the mass is decreased in the later phase. Besides, combining with the application, the writer will simulate the concrete's freezing-thawing process under actual operation conditions with the standard test data, in order to offer the presumption model of freezing-thawing durability and predict the residual freezing-thawing life of the concrete, thus providing theoretical basis for the structure's maintenance, repair, and dismantlement.

Microstructure and life prediction model of steel slag concrete under freezing-thawing environment

2021 ◽  
Vol 10 (1) ◽  
pp. 1776-1788
Author(s):  
Yang Wen ◽  
Hui Sun ◽  
Shuaidong Hu ◽  
Guangmao Xu ◽  
Xiazhi Wu ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Mass Loss ◽  
Frost Resistance ◽  
Mass Loss Rate ◽  
Steel Slag ◽  
Quadratic Function ◽  
Northern China ◽  
Calculation Model ◽  
Dynamic Elastic Modulus ◽  
Resistance Durability

Abstract The goals of this paper are to study the frost resistance of steel slag concrete (SSC), research the damage mechanisms, and predict the service life of SSC in cold regions. First, the stability of steel slag (SS) was tested, and then SS samples with different treatment dosages were used as aggregates to replace natural aggregates of equal volumes in the preparation of C40 concrete. The microstructures of concrete and micro properties of cement hydration products were investigated in nanospace in this research. In addition, rapid frost resistance durability tests were carried out under laboratory conditions. The results revealed that the ordinary concrete (OC) exhibited a more serious damage phenomenon, and the mass loss and relative dynamic elastic modulus of OC were changed by 5.27 and 62.30%, respectively. However, with increases in the SS content, the losses in mass were lowered. Furthermore, the relative dynamic elastic modulus decreased less, and the frost resistance of the specimens was stronger. The range of mass loss rate was between 2.233 and 3.024%, and the relative dynamic elastic modulus range was between 74.92 and 91.09%. A quadratic function with a good fitting degree was selected to establish a freezing-thawing damage calculation model by taking the relative dynamic elastic modulus as the variable. Then, the freezing-thawing durability lifespan of concrete in the colder regions of northern China was successfully predicted by using the damage calculation model. The results of SSC20–60 showed the better frost resistance durability when the content of SS sand was 20% and the dosage of SS stone was 60%. Its frost resistance lifespan was more than twice that of OC, which demonstrated that SS as an aggregate could effectively improve the frost resistance lifespan of concrete to a certain extent.

Experimental Study on Frost Resistance Properties of Pumice Mixed Aggregate Concrete

2012 ◽  
Vol 476-478 ◽  
pp. 1661-1664
Author(s):  
Jun Fang Huo ◽  
Jian Jun Chu ◽  
Hui Yang
Keyword(s):  
Elastic Modulus ◽  
Mass Loss ◽  
Frost Resistance ◽  
Loss Rate ◽  
Mass Loss Rate ◽  
Strength Loss ◽  
Dynamic Elastic Modulus ◽  
Aggregate Concrete ◽  
Freeze Thaw ◽  
Thaw Cycle

Different amount of pumice were used to replace gravel to make mixed aggregate concrete, the fast freeze-thaw cycle test were conducted and the influence of pumice rate substitution to the frost resistance properties of concrete were studied.The mass loss rate, strength loss and relative dynamic elastic modulus were regarded as the evaluation index of frost resistance properties of concrete. Results showed that the mass loss rate and strength loss rate gradually decreased and the relative dynamic elastic modulus gradually increased with the increase of pumice rate, the mass loss rate, strength loss rate and the relative dynamic elastic modulus gradually decreased with the increase of freeze-thaw cycles. Polypropylene fibers could reduce the strength loss rate, improved the relative dynamic elastic modulus, but had little effect to improve the mass loss. Through the frost resistance, the frost resistance of concrete improved with the increase of pumice content, at the same time, polypropylene fiber also could improve the frost resistance of concrete.

scholarly journals Influence of Crack on Concrete Damage in Salt-Freezing Environment

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Guangyan Liu ◽  
Song Mu ◽  
Jingshun Cai ◽  
Deqing Xie ◽  
Ying Zhou ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Mass Loss ◽  
Crack Width ◽  
Mass Loss Rate ◽  
Development Trend ◽  
Initial Crack ◽  
Dynamic Elastic Modulus ◽  
Damage Development ◽  
Concrete Damage ◽  
Freezing Cycle

The damage development trend of concrete with cracks in salt-freezing environment is systematically studied. The cracks are also tested in intact concrete for comparison, and crack characterization is introduced. The mass loss, the relative dynamic elastic modulus, and the change of crack width are analyzed. Results show that the crack width increases as the salt-freezing cycle progresses. Following the development trend of the cracks, concrete cracks can be divided into three categories: 0–40, 40–100, and 100–150 μm. The mass loss increases significantly, and the change of relative dynamic elastic modulus decreases in concrete with an initial crack compared with the intact concrete. When the crack width is 80 μm, a maximum mass loss rate of 0.19% and a minimum relative dynamic elastic modulus of 75.81% can be obtained. These test results prove that crack and freeze-thaw coupling can influence each other and accelerate the failure of concrete. Overall, this study can serve as a basis for the durability design and life improvement of concrete structures.

scholarly journals Experimental Investigation on the Freeze–Thaw Resistance of Steel Fibers Reinforced Rubber Concrete

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1260
Author(s):  
Tao Luo ◽  
Chi Zhang ◽  
Chaowei Sun ◽  
Xinchao Zheng ◽  
Yanjun Ji ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Mass Loss ◽  
Loss Rate ◽  
Bending Strength ◽  
Mass Loss Rate ◽  
Steel Fibers ◽  
Freeze Thaw ◽  
Four Point Bending ◽  
Rubber Concrete

The reuse of rubber in concrete results in two major opposing effects: an enhancement in durability and a reduction in mechanical strength. In order to strengthen the mechanical properties of rubber concrete, steel fibers were added in this research. The compressive strength, the four-point bending strength, the mass loss rate, and the relative dynamic elastic modulus of steel fiber reinforced rubber concrete, subjected to cyclic freezing and thawing, were tested. The effects of the content of steel fibers on the freeze–thaw resistance are discussed. The microstructure damage was captured and analyzed by Industrial Computed Tomography (ICT) scanning. Results show that the addition of 2.0% steel fibers can increase the compressive strength of rubber concrete by 26.6% if there is no freeze–thaw effect, but the strengthening effect disappears when subjected to cyclic freeze–thaw. The enhancement of steel fibers on the four-point bending strength is effective under cyclic freeze–thaw. The effect of steel fibers is positive on the mass loss rate but negative on the relative dynamic elastic modulus.

scholarly journals SN 2009ip: CONSTRAINTS ON THE PROGENITOR MASS-LOSS RATE

2013 ◽  
Vol 768 (1) ◽  
pp. 47 ◽  
Author(s):  
E. O. Ofek ◽  
L. Lin ◽  
C. Kouveliotou ◽  
G. Younes ◽  
E. Göğüş ◽  
...  
Keyword(s):  
Mass Loss ◽  
Loss Rate ◽  
Mass Loss Rate

Effect of Sample Width on Downward Flame Spread over Typical Energy Conservation Material at a High Elevation Area

2014 ◽  
Vol 664 ◽  
pp. 199-203 ◽  
Author(s):  
Wei Guang An ◽  
Lin Jiang ◽  
Jin Hua Sun ◽  
K.M. Liew
Keyword(s):  
Mass Loss ◽  
Flame Spread ◽  
Loss Rate ◽  
Mass Loss Rate ◽  
High Elevation ◽  
Flame Height ◽  
Spread Rate ◽  
Flame Spread Rate ◽  
Sample Width ◽  
Downward Flame Spread

An experimental study on downward flame spread over extruded polystyrene (XPS) foam at a high elevation is presented. The flame shape, flame height, mass loss rate and flame spread rate were measured. The influences of width and high altitude were investigated. The flame fronts are approximately horizontal. Both the intensity of flame pulsation and the average flame height increase with the rise of sample width. The flame spread rate first drops and then rises with an increase in width. The average flame height, mass loss rate and flame spread rate at the higher elevation is smaller than that at a low elevation, which demonstrates that the XPS fire risk at the higher elevation area is lower. The experimental results agree well with the theoretical analysis. This work is vital to the fire safety design of building energy conservation system.

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