Experimental Study of Pre-Stressed Concrete Beams with Fatigue Subjoining Freezing-Thawing Circle

2011 ◽  
Vol 368-373 ◽  
pp. 2346-2350
Author(s):  
Yi Duo Zhang ◽  
Rong Gui Liu ◽  
Yu Chen ◽  
Kai Fu
Keyword(s):  
Experimental Study ◽  
Elastic Modulus ◽  
Design Theory ◽  
Concrete Beams ◽  
Influence Factors ◽  
Degradation Process ◽  
Fatigue Tests ◽  
Dynamic Elastic Modulus ◽  
Ordinary Concrete ◽  
Main Influence

Based on fatigue tests of pre-stressed concrete (PC) and ordinary concrete beams for 15 specimens after different times of freezing-thawing circle, the degradation process for the tested beams of the relative dynamic elastic modulus is conducted. The experimental study shows that the pre-stressing level and times of freezing-thawing circles are main influence factors to durability of test beams. The results of this study are useful for the exploration of the mechanism of the PC structure’s damage and the improvement of design theory concerning the durability of the PC structures.

Experimental Study on Shear Behavior of Combined Aggregate Concrete Beams

2012 ◽  
Vol 166-169 ◽  
pp. 1422-1425
Author(s):  
Yan Kun Zhang ◽  
Hui Liu ◽  
Ze Zao Song
Keyword(s):  
Experimental Study ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Lightweight Aggregate ◽  
Shear Behavior ◽  
Shear Capacity ◽  
Aggregate Concrete ◽  
Design Formula ◽  
Ordinary Concrete

Based on the test，the shear behavior of combined aggregate concrete beams is studied. The results show that combined aggregate concrete beam have similar behavior with ordinary concrete beams, and the shear capacity reduces with the increase of lightweight aggregate. And design formula of the combined aggregate concrete shear capacity is suggested.

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

2011 ◽  
Vol 71-78 ◽  
pp. 4361-4364 ◽  
Author(s):  
Xiao Yan Zhang ◽  
Xin Xin Ding ◽  
Shun Bo Zhao ◽  
Zhan Fang Ge
Keyword(s):  
Experimental Study ◽  
Elastic Modulus ◽  
Mass Loss ◽  
Source Rock ◽  
Crushed Stone ◽  
Dynamic Elastic Modulus ◽  
Cycle Times ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle

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.

Model identification of durability degradation process of concrete material and structure based on Wiener process

2020 ◽  
pp. 105678952096143
Author(s):  
Zhenhao Zhang ◽  
Minhan Liu ◽  
Xin Liu ◽  
Xiao Wang ◽  
Yi Zhang
Keyword(s):  
Elastic Modulus ◽  
Reinforced Concrete ◽  
Wiener Process ◽  
Autocorrelation Function ◽  
Function Method ◽  
Concrete Structures ◽  
Degradation Process ◽  
Dynamic Elastic Modulus ◽  
Concrete Material ◽  
Verification Method

The degradation and damage of concrete material and structure during their service life are significantly characterized by randomness, so it is of great importance to establish a stochastic process model for the structural durability degradation. This study was based on Wiener process to identify the durability degradation of concrete structures. Firstly, two identification methods for Wiener process were introduced, including autocorrelation function method and probability statistics verification method. The former is a rough method for preliminary identification, and the latter is a strict method for accurate identification. According to the degradation processes and damage mechanisms of dynamic elastic modulus of concrete and section stiffness of reinforced concrete girder, and based on relevant data, autocorrelation function method and probability statistics verification method were used to identify whether the degradation processes of concrete dynamic elastic modulus and girder section stiffness conform to Wiener process. The results showed that the degradation process of concrete dynamic elastic modulus and the degradation process of section stiffness of reinforced concrete girder can be modeled with Wiener process. The conclusions contribute to the prediction of performance degradation and the maintenance for concrete structures in service.

Research on Ordinary Concrete Durability

2014 ◽  
Vol 584-586 ◽  
pp. 1318-1321 ◽  
Author(s):  
Peng Cheng ◽  
Xin Fu Chen ◽  
Lang Wu
Keyword(s):  
High Performance ◽  
Influence Factors ◽  
Base Material ◽  
Steel Corrosion ◽  
Corrosion Mechanism ◽  
Concrete Durability ◽  
Ordinary Concrete ◽  
The Status ◽  
The Common ◽  
Main Influence

This paper introduces the common concrete durability research background of the status quo, summarizes the corrosion resistance of concrete under the background of the main influence factors. The corrosion types and corrosion mechanism of concrete are discussed, including the corrosion mechanism of concrete base material of cement, steel corrosion mechanism and corrosion mechanism of reinforced concrete structures. From the research and the analysis of the structure formation of ordinary concrete, summarizes the common strength grade of concrete high performance-based approach.

The Research on the Dyeing Wastewater Treatment in Ultrasonic with Fenton

2014 ◽  
Vol 955-959 ◽  
pp. 2585-2588
Author(s):  
Jun Liu ◽  
Hui Lan Zhang ◽  
Kun You ◽  
Ya Shu Yuan
Keyword(s):  
Experimental Study ◽  
Wastewater Treatment ◽  
Treatment Effect ◽  
Influence Factors ◽  
Dyeing Wastewater ◽  
Experimental Conditions ◽  
Ph Values ◽  
Direct Blue ◽  
Radiation Dosing ◽  
Main Influence

Experimental study on the ultrasonic, Fenton law separate and composite handle direct blue-B2RL dyeing wastewater of main influence factors and treatment effect. Experimental results show that ultrasonic Fenton recombination method > Fenton> ultrasound treatment effect alone . Complex legal pH values, while ultrasonic-Fenton ultrasonic radiation dosing the amount of H2O2 and time and other factors were studied to determine the best experimental conditions.The best experimental conditions is :the dosing the amount of H2O2 3ml/L, pH=3.

Comparison and Selection of the Durability Evaluating Parameters of Concrete in Saline Soil Region

2014 ◽  
Vol 919-921 ◽  
pp. 1751-1754 ◽  
Author(s):  
Li Zhang ◽  
Xiao Ping Su
Keyword(s):  
Elastic Modulus ◽  
Saline Soil ◽  
Degradation Process ◽  
Dynamic Elastic Modulus ◽  
Failure Behavior ◽  
Concrete Durability ◽  
Salt Corrosion ◽  
Concrete Damage ◽  
Main Index ◽  
Durability Of Concrete

The mal-condition of environment directly affects the durability of concrete, and which has become a widespread problem under the complicated environment conditions. Domestic and overseas scholars have carried out many researches on the durability of concreteunder different environmental conditions. The mass and the dynamic elastic modulus loss are focused as two major criteria in the evaluation of concrete damage. The article further gives researches on the durability of concrete in the saline soil environment in the west region of Jilin province. The concrete durability tests are conducted under the actions of salt soaking, salt corrosion and freezing-thawing cycles, and salt corrosion and dry-wet cycles. Comparing the test results in the same coordinate system, it is concluded that the dynamic elastic modulus of concrete can reflect the degradation process of concrete performance more accurately and intuitively, and forecast the failure behavior of concrete under the action of various environmental factors timely and effectively. Therefore it can be used as the main index for no damage detection, while the mass loss can be acted as the auxiliary detection index during the concrete durability tests.

Experimental Study of Frost-Resistance Properties of Silica Fume Concrete

2014 ◽  
Vol 584-586 ◽  
pp. 1626-1629 ◽  
Author(s):  
Zhi Gang Yin ◽  
Jun Feng ◽  
Shu You Huang ◽  
Bing Fang Zhao
Keyword(s):  
Elastic Modulus ◽  
Silica Fume ◽  
Frost Resistance ◽  
Dynamic Elastic Modulus ◽  
Test Results ◽  
Change Rate ◽  
Ordinary Concrete ◽  
Thawing Cycle ◽  
Different Content

The frost resistance of low strength concrete is researched. In order to evaluate the effect of different content of silica fume on frost resistance，the quality of the cement 6%, 9%, 12% silica fume are respectively added into concrete. Freezing-thawing test results show that: the silica fume concrete has good frost resistance. Content of silica fume on concrete is not almost effect to quality loss rate. In 0-250 times of freezing-thawing cycle range, it is smaller that relative dynamic elastic modulus change rate. Relative dynamic elastic modulus of ordinary concrete decreases rapidly after 250 times of freezing-thawing cycle while dynamic elastic modulus decrease rate of the silica fume concrete tends to slow. The freezing -thawing cycles up to 350 times, silica fume concrete relative dynamic elastic modulus is 1.5 times that of ordinary concrete that show the silica fume concrete frost resistance is better than that of ordinary concrete.

Fatigue Tests on Prestressed Concrete Beams Made With Debonded Strands

PCI Journal ◽  
1994 ◽  
Vol 39 (6) ◽  
pp. 70-88
Author(s):  
Bruce W. Russell ◽  
Ned H. Burns
Keyword(s):  
Prestressed Concrete ◽  
Concrete Beams ◽  
Fatigue Tests
Sign in / Sign up

Export Citation Format

Share Document